The right light - Energy Saving Trust

The right light - Energy Saving Trust
The right light
Selecting low energy lighting
introduction for designers and house builders

Produced in association with
The right light - Energy Saving Trust
Energy Saving Trust                                                                           Energy Saving Trust
Selecting low energy lighting                                                                 Selecting low energy lighting

                          Contents                                                            1. Welcome
                          1. Welcome                                                    03
                          2. Introduction                                               04                    To appreciate the recent advances in lighting, we should consider the
                                                                                                               historical perspective. Though there was a move towards the use of
                          3. L ow energy lighting –definition, compliance and safety   05                    fluorescent light tubes in the 1960s, incandescent light bulbs remained
                                                                                                               our main source of domestic lighting for over 90 years. Standard
                          4. Domestic lighting – available technology                   09                    solutions for lighting our homes became established with the typical
                          5. C
                              onsiderations when selecting low energy lamps            15                    40, 60 or 100 watt incandescent lamps available, and any slight
                                                                                                               deficiencies in lighting were easily addressed with a higher wattage
                          6. Lighting guidance for the home                             25                    bulb or by investing in a multi-lamp fitting. Energy was cheap and we
                                                                                                               had little concern over the fact that our light bulbs were only 10%
                          7. Information sources                                        30                    efficient, generating only a miserly dozen or so lumens of light per watt.
                          Index31                                                                             A very different attitude to lighting has emerged in the last few years.
                                                                                                               Partly driven by legislation, but also by a growing public appreciation of
                                                                                                               the role good lighting can play in improving their homes. Lighting has
                                                                                                               become a lifestyle statement. Homeowners are now looking for wall
                                                                                                               washes, spot-lit features, subtle accent lighting, clever use of colour
                                                                                                               temperature and colour rendition, and the ability to control lighting for
                                                                                                               different moods and activities. In addition they are increasingly aware
                                                                                                               of the environmental benefits, reduced lighting bills and flexibility that
                                                                                                               LED technology can provide.

                                                                                                               Energy Saving Trust hopes ‘The right light’ will provide a useful starting
                                                                                                               point for designers and house builders who have not yet developed
                                                                                                               expertise in the use of low energy lighting, and want to prepare
                                                                                                               themselves for a future which will inevitably be dominated by LED
                                                                                                               technology. With increasing choice, covering a range of lighting
                                                                                                               characteristics, this guide makes a timely contribution to ensuring that
                                                                                                               LED product selection is as informed as possible.

                                                                                                               Energy Saving Trust

                          Energy Saving Trust is grateful to the NHBC Foundation for
                          funding the development of this guide and providing support
                          during its preparation.

                          Energy Saving Trust thanks PhotonStar LED Ltd for supplying
                          much of the imagery used in this guide.

02                                                                                                                                                                                          03
The right light - Energy Saving Trust
Energy Saving Trust                                                                                               Energy Saving Trust
Selecting low energy lighting                                                                                     Selecting low energy lighting

2. Introduction                                                                                                   3. Low energy lighting –
                                                                                                                      definition, compliance and safety
                 Historically, lighting has accounted for just under 3% of the annual
                 overall energy use in homes, and was not viewed as a priority for energy                                          European perspective
                 efficiency measures or initiatives. Once the emphasis shifted to
                 addressing carbon emissions, lighting, with its dependence on grid                                                Since 1998 there has been European                        and most halogen lamps (all those with
                 electricity (with relatively high emissions per kW generated) became a                                            guidance on the energy efficiency of                      energy rating E and some in rating D)
                 significant consideration for Government.                                                                         lighting, initially through EU Commission                 being excluded. In April 2015 the European
                                                                                                                                   Directive 98/11/EC. This established an                   Commission announced plans to increase
                 Since 2000, a number of drivers, including national and international                                             energy efficiency rating scale for lamps                  these minimum efficiency requirements
                 legislation, together with standards, such as the Code for Sustainable                                            (originally A to G) similar to that already               and current proposals are for a phase out of
                 Homes, have stimulated innovation in low energy lighting technology,                                              introduced for electrical appliances such                 the majority of D rated halogen lamps from
                 and its adoption in new and existing homes. Compact fluorescent                                                   as refrigerators and washing machines.                    September 2018.
                 lamps (CFLs) and halogen incandescent lamps initially offered the main                                            Initially, the term ‘energy efficient’ was
                 alternatives to traditional tungsten incandescent bulbs, which were                                               applied to lamps which used less power                    With the least efficient lighting now being
                 phased out from 2009. However, it is LED (Light emitting diode)                                                   (for a given light output) than the standard              phased out, new ratings (A+ and A++) were
                 technology that seems set to truly revolutionise the energy                                                       tungsten incandescent light bulb available                introduced at the top of the efficiency scale
                 efficiency of lighting.                                                                                           at the time. Initially, products with only a              to recognise the high-end innovation in
                                                                                                                                   marginal improvement over standard lamps                  lamp technology. Figure 1 illustrates some
                 With LED lighting, the speed and magnitude of change is quite                                                                                                               of these changes and shows the range of
                 remarkable. The traditional incandescent light bulb, which offered                                                (such as halogen incandescent lamps) were
                                                                                                                                   accepted as part of the product mix                       performance for the main types of domestic
                 about 12 lumens per watt and a life of about 1,000 hours, can now be                                                                                                        lamps. It is now a legal requirement to
                 replaced by an LED lamp with an output exceeding 100 lumens per                                                   available for energy efficient lighting.
                                                                                                                                                                                             display the rating scale on packaging for
                 watt and potentially 35,000 hours of use or more. In addition, LEDs                                               Subsequent European legislation which                     domestic lighting. Proposals to re-base the
                 have been adapted to overcome their earlier limitations: they can now                                             came into effect from 2009 has served to                  rating scale to establish new A to G ratings
                 provide a range of colour temperatures to create ambience, many are                                               refine what is meant by energy efficient                  are currently being consulted on by the
                 fully dimmable and a range of beam angles are available to tailor light                                           lighting, with tungsten incandescent lamps                EU Commission.
                 distribution. The critical change over the last eighteen months has been
                 on affordability; good quality lamps are now available for under £6,                                               Status                            Energy     Comparative                           Ranges for lamp types
                 often less than half the price they were a year ago.                                                                                                 Rating     energy use*
                                                                                                                                    New European ratings
                 In terms of running cost, research1 has shown that in a typical home the                                           from 2013, for highly              A++       Less than 11%
                                                                                                                                    efficient lamps
                 fixed lighting alone accounts for round 15% of all electricity use (a                                                                                 A+        11 to 17%

                 figure which rises considerably if plug in lighting is also included). In
                 new homes, despite the requirement to include a proportion of low                                                                                       A       17 to 24%

                 energy lighting (with CFLs the predominant choice), any efficiency                                                                                      B       24 to 60%
                 benefits may be offset by the greater number of light fittings used,
                 particularly in kitchens and bathrooms. However, a switch to 100% LED                                                                                   C       60 to 80%

                 lamps would significantly reduce electrical consumption for lighting,                                              To be phased out from 2018           D       80 to 95%
                 compared with the typical CFL/halogen solution. It is noted that some
                 house builders are already aware of the benefits of LEDs, and are                                                  Products now being phased out         E      100%                               Halogen
                 beginning to install them routinely.                                                                               These older European
                                                                                                                                    ratings now deleted
                                                                                                                                                                          F      100 to 130%

                                                                                                                                    E & F rated lamps now phased
                                                                                                                                    out for everyday domestic use        G       More than 130%     Tungsten

                 1   Powering the nation. Household electricity-using habits revealed. Energy Saving Trust.2012
04                                                                                                                                 Figure 1 Understanding European energy ratings for lamps. This chart compares non-directional (bulb-like) lamps. 05
                                                                                                                                   *Compared with the energy use of a typical tungsten incandescent bulb.
The right light - Energy Saving Trust
Energy Saving Trust                                                                                               Energy Saving Trust
Selecting low energy lighting                                                                                     Selecting low energy lighting

                 UK perspective
                 In England, low energy domestic lighting is      editions of Part L1A are required to have
                 defined in the Domestic Building Services        energy efficient lamps in a minimum of
                 Compliance Guide, which supports Part L1A        75% of the interior light fittings. More                           One switch should operate no more than six light fittings with a maximum load
                 of the Building Regulations. In summary,         detail on compliance to the English Building                       of 100 circuit watts.
                 new homes, built to either 2010 or 2013          Regulations is shown below.                                        Explanation: this is unlikely to be a limitation if LED lamps are used. There might be
                                                                                                                                     some constraints if you are considering using higher output CFLs. Halogen lamps will
                                                                                                                                     considerably reduce flexibility for linking more than one fitting to a single light switch.
                                                                                                                                     Lampholders may be dedicated or standard.
                                                                                                                                     The Building Regulations no longer require dedicated lampholders/sockets for low
                 Meeting Building Regulations (England) Part L1A 2013                                                                energy lamps. Standard bayonet or Edison screw sockets are acceptable for all low
                                                                                                                                     energy lamps with integral control gear (like LEDs and CFLs). Pin fittings will still be
                 Summary of requirements for fixed lighting as set out in the Domestic Building Services                             required for linear fluorescent lamps and others with separate control gear.
                 Compliance Guide (England), together with explanatory notes
                                                                                                                                     For fixed external lighting there are two compliant options.
                   At least 75% of the interior light fittings must be fitted with low energy lamps.
                 •	                                                                                                                 For energy efficient lamps (with efficacy above 45 lumens per circuit watt)
                   Explanation: a light fitting may hold one lamp (e.g. a typical downlight) or several                              automatic switch-off is needed when daylight is sufficient, but manual control of light
                   lamps (e.g. a chandelier).                                                                                        fittings allowable.
                   Exemption: when working out the 75%, exclude light fittings in cupboards, wardrobes
                   and other similar places where light is needed rarely or for very short periods.                                    For less efficient lamps (up to 100 lamp watts per fitting) automatic controls are
                                                                                                                                       required for switch-off when daylight is sufficient and when the lit area is unoccupied.
                   A low energy lamp must provide a minimum of 45 lumens per circuit watt.
                   Explanation: Only fluorescent lamps and LEDs achieve these levels. Halogen lamps                                These requirements are the minima that might be specified in a design to meet Part L1A.
                   don’t qualify. A ‘circuit watt’ includes all electrical loading on the circuit including the                    To comply with Part L1A, the design team may have put greater reliance on lighting in
                   lamp (it should not be confused with the efficacy of the lamp itself, expressed in                              meeting the Design Emission Target (DER) of the home, and in practice the design may
                   lumens per watt, which will be a higher value).                                                                 call for a higher (more energy efficient) specification than that shown above.
                   Light fittings consuming less than 5 circuit watts are not counted towards the
                   75% target.                                                                                                     While the legal requirements for lighting are similar throughout the UK, each
                   Explanation: This requirement was included to ensure that low wattage decorative                                country has its own Building Regulations:
                   lamps etc., were not included as part of the 75% low energy light fitting compliance in
                   Part L. If using LEDs be aware that many LED products rated at around 5 watts are on                            England The Building Regulations 2010 Conservation of Fuel and Power in new dwellings,
                   the market: for these to be included within the 75% compliance figure, each lamp                                Approved Document L1A. (2013 edition). See Domestic Building Services Compliance Guide
                   must exceed a minimum light output (see below).                                                                 for guidance.

                   Fittings must have an output greater than 400 lumens.
                 •	                                                                                                               Wales The Building Regulations 2010 Conservation of Fuel and Power, Approved Document
                   Explanation: Low output lamps (400 lumens or below) are considered to make a                                    L1A: New dwellings (2014 edition).
                   limited contribution to a home’s lighting and cannot be counted towards the 75% low                             Scotland Building (Scottish) Regulations 2004, Technical Handbook – Domestic 2015
                   energy lighting target in Part L. Note that the ‘over-400 lumens’ target relates to the                         Section 6: Energy.
                   whole fitting (the luminaire). However for typical downlights, which are flush mounted                          Northern Ireland Building Regulations 2012, Technical Booklet F: Conservation of Fuel and
                   on ceilings, the lumen output of the lamp itself can be used for compliance.                                    Power (October 2012).

06                                                                                                                                                                                                                              07
The right light - Energy Saving Trust
Energy Saving Trust                                                                                              Energy Saving Trust
Selecting low energy lighting                                                                                    Selecting low energy lighting

                 Best Practice                                                                                   4. Domestic lighting – available technology
                 Building Regulations set minimum standards of performance to be achieved. Careful
                 selection of lighting can achieve better value for householders, and achieve lower carbon                          This section introduces the main types of low energy lighting available for domestic use.
                 dioxide emission rates from lighting in design calculations. Today, good practice would be                         Figure 2 gives an overview of equivalence between the three main lamp types available
                 the adoption of low energy lighting lamps in 100% of a home’s light fittings. Best practice                        today, compared with the now obsolete tungsten incandescent lamps. Figure 3 shows how
                 would be a 100% adoption of high efficiency LED lighting with efficacy above 100 lumens                            lamps have evolved over time and in particular the rapid improvements in efficiency
                 per watt.                                                                                                          achieved and projected for LED lamps. Many of the terms and performance characteristics
                                                                                                                                    included in this section are explained in more detail in Section 5 of this guide.
                  afety standards
                 Specified lighting systems must be CE tested (European Conformity) with accompanying                                                What we                                                       What’s available today
                 compliance documentation from credible sources.                                                                                    used to buy
                 EU safety and performance standards for LEDs are explained in the 2012 IEP publication:                                            Now phased out                               Still available
                                                                                                                                                                                                                                   Classed as energy efficient
                                                                                                                                                                                                                                      (Part L1A compliant)
                 A Guide to the Specification of LED Lighting Products. Special care should be taken when
                                                                                                                                                       Tungsten           How much light?           Halogen
                 installing downlighters (see below).                                                                                                Incandescent         (lamp output in        Incandescent                   CFL                       LED
                                                                                                                                                         lamps                lumen)                 lamps                    lamps                      lamps

                                                                                                                                                          40W                                        28W                       9W                         5W

                 Notes on the installation of downlighters                                                                                                        lamp
                                                                                                                                                                                                                    or                         or
                 When installing downlighters there are a number of practical considerations which should
                 be considered:                                                                                                                           60W                                        42W                     12 – 15W                   7 – 10W

                 Fire resistance                                 Special care is needed where downlighters                                                        lamp
                                                                                                                                                                              800        same
                                                                                                                                                                                        output                      or                         or
                 For ceilings, plasterboard normally provides    are to be installed in insulated ceilings at                                                      was       Lumen       from
                 part of the fire resistance of the home. If     loft or roof level. Special supports are
                 downlighters are to be installed in ceilings,   available to keep insulation a suitable                                                  100W                                       70W                     23 – 28W                  14 – 19W
                 they must not reduce fire resistance below      distance away from downlighters installed                                                                               same
                                                                                                                                                                  lamp        1600
                 that required in Building Regulations           at loft level. For rooms in the roof, keeping                                                   output
                                                                                                                                                                   was       Lumen
                                                                                                                                                                                                                    or                         or
                 Approved Document B. It is important to         an air gap around downlighters will cause a
                 ensure that the type of downlighter used        cold bridge in the roof and the additional
                                                                                                                                    Figure 2 Compared with tungsten incandescent light bulbs, modern lamps, particularly CFLs and LEDs, require a
                 has test evidence to support its use in a       heat loss will need to be accounted for in                         fraction of the power to generate an equivalent level of light.
                 particular situation.                           thermal performance calculations.
                 Overheating and thermal performance             Moisture control

                 Unless there is adequate air space around a     If downlighters are to be used in bathrooms,

                                                                                                                                                    150                                                                               KEY
                 downlighter, the lamp and surrounding air       showers or wet rooms it is important that

                                                                                                                                                                                                                                         Tungsten incandescent lamps
                 can overheat. Overheating will reduce the       they do not allow moist air to spread to

                                                                                                                                  Lumens per Watt
                                                                                                                                                                                                                                         Linear fluorescent lamps
                 performance and life of lamps, and in the       other parts of the home, such as roof                                              100                                                                                  Halogen incandescent lamps
                 case of halogen lamps in particular, with       spaces, where condensation can occur. For
                                                                                                                                                                                                                                         Compact fluorescent lamps
                 their high operating temperatures, can          rooms that generate moisture, select
                 result in a fire risk. Manufacturers provide    downlighters which provide a vapour seal.                                           50                                                                                  LED lamps

                 guidance on the air space required around
                 downlighter units, and maximum operating
                 temperatures are included in the                                                                                                     1940           1960             1980             2000                 2020
                 specifications for LED lamps.                                                                                                                                        Year
                                                                                                                                    Figure 3 Domestic lighting – performance development over time.
08                                                                                                                                                                                                                                                                   09
The right light - Energy Saving Trust
Energy Saving Trust                                                                                           Energy Saving Trust
Selecting low energy lighting                                                                                 Selecting low energy lighting

                 Halogen lamps                                                                                                 Fluorescent lighting

                 Halogens are incandescent lamps using a        Though halogens lamps have been used                           Inside a fluorescent lamp or tube an            Fluorescent lighting offers long service life
                 filament suspended in a small amount of        very commonly for downlighting, their high                     electrical charge is passed through mercury     and is very energy efficient, with most
                 halogen (iodine or bromine) gas. They work     energy consumption and relatively short                        gas. This generates UV light, which then        types complying with Part L1A
                 at high temperature and can be more            service life are now recognised                                excites a phosphorescent coating on the         requirements for low energy lighting.
                 efficient than traditional tungsten            disadvantages. Even the best halogen                           inside of the tube to generate visible light.   Though associated with cool light and slow
                 incandescent bulbs. Halogen lamps produce      lamps have efficacy ratings and service                                                                        start up times, advances in fluorescent
                 an attractive bright white light, reach full   lives which are well short of the                              A ballast is needed for fluorescent lighting    lighting have led to a range of products
                 lighting level immediately and can last        performance offered by CFLs and LEDs.                          to supply a suitable amount of current for      which are satisfactory in many domestic
                 from 1,000-3,000+ hours. Currently, they do    If considering halogen lamps, choose a                         startup: this can be incorporated into the      situations. Fluorescent lamps are
                 not meet the 45 lumens/circuit watt            product with the best possible service life                    bulb’s design or can be an attachment on        manufactured in two distinct types: linear
                 requirement for low energy lighting in Part    (some offer 3,000 hours) and select                            the light fitting.                              fluorescent lamps (LFLs) and compact
                 L1A of the Building Regulations. From 2018,    energy class B.                                                                                                fluorescent lamps (CFLs).
                 even the most efficient halogen lamps will
                 be phased out of producton.
                                                                                                                               Linear fluorescent lamps (LFLs)
                 Positives                                      Negatives
                                                                                                                               LFLs are the familiar ‘light tubes’, which      under cabinets), in home offices, utility
                 •		     Low purchase price                     •		The best products are in energy                            have been in common use from the 1960s.         rooms and bathrooms.
                                                                    efficiency rating B: halogens are                          They typically produce very bright light. In
                 •		Colour temperature: good,                      therefore not classed as ‘energy                                                                           Unlike CFLs (see next page) LFLs do not
                     although limited to around                                                                                domestic settings this has made LFLs
                                                                    efficient’ in Part L1A of the                              popular for task lighting in kitchens (e.g.     have integrated ballasts, and require a
                     3,000K                                         Building Regulations                                                                                       dedicated fitting.
                 •		Colour rendering: excellent                •		High running costs
                     (CDI near to 100)                                                                                         Positives                                       Negatives
                                                                •		Short life: 2,000 hours typical
                 •		No warm up time                                                                                           •		Energy efficiency class A, and              •		Must have ballast/ control gear
                                                                •		Very high surface temperature.                                 classed as ‘energy efficient’ in                as part of the light fitting
                 •		Easily dimmable.                                                                                              Part L1A of the Building
                                                                                                                                   Regulations                                 •		Contain mercury and must be
                                                                                                                                                                                   disposed of carefully
                                                                                                                               •		Low running costs
                                                                                                                                                                               •		Colour rendering: halophosphate
                                                                                                                               •		Long life: 20,000 hours+                        types – poor or moderate (up to
                                                                                                                                                                                   CRI 69).
                                                                                                                               •		Range of colour temperatures:
                                                                                                                               •		Colour rendering: triphosphate or
                                                                                                                                   multiphosphate types – very
                                                                                                                                   good/excellent (CRI 80+)
                                                                                                                               •		Warm up time very short
                                                                                                                               •		Some can be dimmable but need
                                                                                                                                   special control gear.
10                                                                                                                                                                                                                         11
The right light - Energy Saving Trust
Energy Saving Trust                                                                                                  Energy Saving Trust
Selecting low energy lighting                                                                                        Selecting low energy lighting

                 Compact fluorescent lighting (CFLs)                                                                                  LEDs (Light emitting diodes)

                 When incandescent bulbs were being            Both CFLs (and dedicated fittings for CFLs)                            In an LED lamp, an electrical current is        LED lamps are now available for almost
                 phased out, CFLs were the most obvious        are available in a wide range of sizes,                                passed across semiconductor material            every domestic lighting purpose. Lamps are
                 replacement, offering potential savings of    shapes and colours. Some CFLs are suitable                             (usually silicon). As electrons migrate         available that can be fitted into traditional
                 up to £50 over the lifetime of the lamp.      for dimming but require specialist,                                    between charged atoms in the                    pendant light fittings containing bayonet,
                 CFLs are highly energy efficient (usually     compatible control gear.                                               semiconductor, photons of light are             cap or Edison screw lamp holders.
                 class A) and remain a good choice for areas                                                                          released. LEDs, and the less well known         Downlights, traditional bulb-shaped lamps,
                 requiring long periods of lighting, for       Some CFLs have glass that is bent or                                   OLEDs (organic light-emitting diodes) and       linear tube types and candle style lamps are
                 example living rooms, however it is clear     spiraled to achieve a more compact shape.                              PLEDs (polymer light-emitting diodes) are       all available.
                 that LED alternatives are now offering even   There are also ‘bulb’ designs although                                 different categories of solid state lighting.
                 greater advantages. Earlier CFLs had          these include a second layer of glass and                                                                              It is recommended that only dedicated LED
                 inconveniently long warm up times before      are therefore less efficient, typically                                LED lighting is the most efficient type         luminaires, dimmer switches and other
                 reaching a good level of light output,        energy class B.                                                        of lighting system currently available for      control gear are specified for LED lamps.
                 however this aspect of performance is less                                                                           domestic use. Technological advances,           When using LEDs as replacements there can
                 of a concern with newer CFL technology.                                                                              continuing cost reduction, rapid product        be operational issues associated with
                                                                                                                                      innovation and diversity make it almost         existing transformers and dimmer switches,
                 Positives                                     Negatives                                                              inevitable that LEDs will be the predominant    and these should be replaced with LED-
                                                                                                                                      form of lighting in the near future.            compatible electronics.
                 •		Normally energy efficiency           •		Short warm-up time needed in
                     class A: rated as ‘energy efficient’     some products                                                           They are very efficient and many offer 80       Summary guidance on selecting LEDs is
                     under Part L1A of the Building                                                                                   to 100 lumens per watt, though note that        given below, but Section 5 gives more
                     Regulations                          •		Contain mercury and must be                                             some products may be only marginally            detail about key selection criteria.
                                                              disposed of carefully                                                   more efficient that the best CFLs. In addition,
                 •		Low running costs                                                                                                they have very long lifetime expectancy
                                                          •		Some not suitable for dimming                                           (many offering 35,000 hour life or more).
                 •		Long life: 8,000-15,000 hours            using pre-existing ‘standard’
                                                              domestic dimmer switches.                                               Positives                                       Negatives
                 •		Wide range of colour
                     temperature: 2,700K-6,000K                                                                                       •		Energy efficiency class A+: rated           •		Higher purchase price
                 •		Colour rendering: very good to                                                                                       as ‘energy efficient’ under Part                (but prices falling rapidly)
                     excellent (some offering CRI 100)                  A note about mercury content                                      L1A of the Building Regulations
                                                                        CFLs do contain small amounts of
                                                                                                                                                                                      •		Variation in quality and
                 •		Some have integral control gear                    mercury but at legal limits – only 3-5                        •		Low running costs – significant                 performance
                                                                        milligrams. Care should be taken when
                     allowing dimming                                   fluorescent light bulbs are broken
                                                                                                                                          lifetime cost savings
                                                                        however, with disposal carried out in line
                                                                                                                                                                                      •		For dimming, specific circuits
                 •		Some have minimal warm up time.                    with manufacturer’s recommendations.                          •		Long lamp life: 30,000 hours or                 and lamps must be specified.
                                                                                                                                          more predicted for many
                                                                                                                                          products                         The following characteristics are
                 The following characteristics are important when specifying CFLs:                                                                                         important when specifying LEDs:
                 •	Minimum lamp lifetime of 10,000 hours                                                                             •		Wide range of colour temperature •	Lumen output
                 •	Lumen maintenance of >76 per cent at 10,000 hours                                                                     2,700-6,000K                     •	Luminous efficacy (lumen output per
                 •	Colour rendering index not less than 80 CRI                                                                       •		Good colour rendition available     watt of power used)
                 •	Power factor not less than 0.9                                                                                                                         •	Lumen maintenance and rated life
                 •	Colour temperature of 2,700K                                                                                      •		Minimal heat output              •	Colour temperature (this may be
                 •	Luminous efficacy >55 lumens per watt                                                                                                                     expressed as a CCT measure)
                 •	Minimum 35 per cent lumen output 2 seconds after switching on                                                     •		Wide range of lumen outputs/     •	Colour rendering (CRI index)
                 • Minimum 80 per cent lumen output 60 seconds after switching on.                                                        beam angles.                     •	Operating temperature.
12                                                                                                                                                                                                                              13
The right light - Energy Saving Trust
Energy Saving Trust                                                                                                                                                                              Energy Saving Trust
Selecting low energy lighting                                                                                                                                                                    Selecting low energy lighting

                                                        A comparison of today’s main low energy lighting options                                                                                5. Considerations when
                                                        Table 1 (for individual lamps) and Figure 4 (for a typical home) highlight                                                                   selecting low energy lamps
                                                        the benefits of specifying LED lighting. It is clear that halogen lighting                                                                                Lighting is an important part of a home. Well-considered lighting saves energy, provides
                                                        is expensive to operate and lamps will need to be replaced frequently.                                                                                    flexibility for creating the right ambience and will contribute to the well-being of
                                                        CFLs offer a significant additional energy saving and will typically last                                                                                 occupants. The guidance below, which includes some special considerations when
                                                        for over 10 years. LEDs offer the dual benefit of very low energy                                                                                         choosing LED lamps, will help to get the most out of electrical lighting and avoid some
                                                        consumption and a long lamp life of up to 30 years.                                                                                                       of the pitfalls in lamp selection.

                                                        Cost per lamp: LEDs compared with CFLs and halogens.                                                                           Table 1

                                                                                                                                     LED                CFL                 Halogen                               Is the lamp energy efficient? Think in lumens, not watts
                                                         Watts (equivalent lamps)                                                    6W                 11W                 35W
                                                                                                                                                                                                                  Low energy lamps must state their light                      lumens per watt) or CFLs (which might
                                                         Purchase price per lamp                                                     £6.00              £3.50               £2.00
                                                                                                                                                                                                                  output (lumen) and the power (watts) used                    achieve 40-60 lumens per watt).
                                                         Typical annual lamp use (hours)                                             1,000h             1,000h              1,000h
                                                                                                                                                                                                                  to create that light. This enables selection
                                                         Typical lamp lifetime (in hours)                                            30,000h            10,000h             2,000h                                on how efficient lamps are at generating                     The number of lumens per watt (described
                                                         Typical lamp lifetime (years)                                               30 years           10 years            2 years                               light from electricity.                                      as the efficacy of a lamp) is the key market
                                                         Cost of lamp purchases over 30,000 hours/30 years                           £6.00              £10.50              £30.00                                                                                             differentiator in the low energy lighting
                                                         Annual energy consumption per lamp                                          6kW                11kW                35kW                                  Innovation, particularly among LED                           market, and a key consideration for
                                                         Annual electricity cost per lamp at 14.05/kW                                £0.84              £1.55               £4.92                                 manufacturers, is rapidly increasing the                     specifiers, or those choosing lamps for
                                                         Total cost per lamp per year                                                £1.04              £1.90               £5.92                                 lumen output for each watt of power used                     their own home. Efficacy varies significantly
                                                         (averaged over a typical LED lamp life – 30 years)                          per year           per year            per year                              (see Figure 3). Today, the most advanced                     between different LED products, so always
                                                                                                                                                                                                                  LED lamps may achieve as much as 120                         check this value before purchasing. Tests of
                                                                                                                                                                                                                  lumens per watt, far superior to the                         LED lamps show that efficacy levels stated
                                                                                                                                                                                                                  performance of tungsten incandescent                         by manufacturers are generally achieved
                                                                                                                                                                                                                  lamps (which typically offered 12-14                         in practice.
                                                                                                                                                       Over 25 years the
                                                       2,500                                                                                           original 8 halogens
           Cost of electricity and replacement lamps

                                                                                Home fitted with 32 LED lamps
                                                                                                                                                       need replacing 12
                                                                                Home fitted with 24 CFLs and 8
                                                       2,250                    halogen lamps (Part L1A compliant)                                     times. The original
                                                                                                                                                       24 CFLs need
                                                       2,000                    Halogen lamp replacement                                               replacing twice
                        (£ today’s prices)

                                                                                CFL replacement
                                                                                                                                                                                                                     A note about lamp recycling
                                                                                                                                                                                                                     CFLs and LED lamps should be recycled in an appropriate manner and not disposed of in household
                                                       1,250                                                                                                                                                         rubbish. In Europe the collection and recycling of CFLs and LED lamps is compulsory under the Waste
                                                                                                                                                       Over 25 years no                                              Electrical and Electronic Equipment (WEEE) Directive. There are two main options for recycling lamps.
                                                       1, 000                                                                                          replacement                                                   The first is to take the lamps to a local council waste recycling centre, which will have dedicated receptacles for
                                                                                                                                                       needed. The original                                          their disposal. Alternatively, an increasing number of ‘Bulbstore’ containers can be found located in the recycling
                                                         750                                                                                           32 LED lamps may                                              areas of retail car parks and inside larger retail outlets.
                                                                                                                                                       exceed 25 year life
                                                         500                                                                                                                                                         Further information on lamp recycling can be found on the Recolight website (,
                                                                                                                                                                                                                     a recycling initiative set up by the lighting industry in 2005.
                                                                0   1   2   3   4   5 6   7   8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25
                                                                                      Time – years since lamps first installed

                                                        Figure 4 Cost of low energy lighting in a typical home with 32 lamps. Cumulative costs of 100% LED lighting
                                                        compared with a Part L1A compliant solution (75% of fittings using CFLs and 25% of fittings using halogen lamps).
                                                        Replacement intervals: halogen = 2 years, CFL = 10 years, LED = 25 years+. Cost of electricity = 14.05p per kWh. Equivalent lamp
                                                        output specifications. Single-lamp fittings throughout.
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Selecting low energy lighting                                                                                                          Selecting low energy lighting

                 How much light? Don’t confuse lumens and lux                                                                                           Importance of beam angle – concentrated or diffuse light
                 The lumen rating printed on packaging                        is needed to ensure that lamps are capable                                Beam angle is an important characteristic                    For a given lumen output, an increase in
                 tells you how much visible light a lamp                      of meeting a target lux level in homes. So                                in lamp choice, particularly for                             beam angle dramatically reduces the lux
                 generates (how bright it is as a source of                   for a floor illumination target of 150 lux, a                             downlighting. With traditional tungsten and                  levels achieved on surfaces (Figure 7). Also
                 light). As light leaves a lamp source, it                    seemingly ‘generous’ 220 lumen rating for a                               halogen incandescent bulbs, light emerges                    note how narrower beam angles can result
                 spreads out and illuminates any surfaces it                  downlighter lamp (Figure 5b) does not meet                                in most directions and is not ‘directional’                  in surprisingly high lux levels on surfaces
                 encounters. Illumination levels on surfaces                  the target (even though the lamp has a                                    (Figure 6). A feature of LEDs and                            relatively near to a lamp (Figure 5).
                 (measured in lux) are highest near to the                    fairly narrow beam angle). In this case, a                                downlighter lamps is that they are
                 lamp but decrease rapidly as the distance                    320 lumen lamp is needed to achieve a                                     ‘directional’ and concentrate most of their                  For downlights, a beam angle of 38o or more
                 from the lamp increases, as shown in                         typical target of 150+ lux for this kitchen                               light output within a specified beam angle.                  is normally sufficient for general lighting,
                 Figure 5. A lux value is the amount of light                 floor (Figure 5a).                                                        Even ‘bulb’ shaped LEDs have a beam angle,                   however achieving the right balance
                 (the number of lumens) illuminating a                                                                                                  typically between 110o and 160o and,                         between beam angle and lumen output is
                 square metre of surface.                                     In the examples shown in Figure 5, the lamps                              compared with an incandescent light bulb,                    crucial to avoid surfaces being poorly
                                                                              are flush fitting and have no additional                                  more of the light they generate is emitted                   illuminated, unevenly lit or possibly over-lit.
                 Lighting design aims to achieve target lux                   luminaire lenses or diffusers – in such cases                             in a useful direction.
                 (illumination) levels on key surfaces – for                  the lumen rating of the lamp can be used to
                 example on floors, stairs and worktops.                      calculate lux levels. Where lamps are fitted
                 There are recommended lux levels for                         within luminaires with additional
                 different rooms in a home and these are                      transparent covers or diffusers (and any
                 included in Section 6.                                       situation where a lamp shade is required), it
                                                                              is important to consider the lumen output
                 As Figure 5 shows, lumens and lux are not                    from the fitting, not just the lamp.
                 equivalent/interchangeable units and care

                                     320 lumen lamp                      220 lumen lamp
                                                                                                                                                                                                   LED bulb-type lamp
                                                                                                                                                                                                    May be classed as
                                                                                                                                                                                               ‘directional’ if 80% of the
                                                                                                                                                            Incandescent halogen bulb                                                LED downlighter lamp
                              38°                                                           38°                                                                                                light emitted falls within a
                                                                                                                                                              Non-directional lamp:            120° cone (and may have a               Directional lamp:
                             beam                                                          beam
                                                                                                                                                          light given off equally in most         specified beam angle).                  light given off
                             angle                                                         angle
                                                                                                                                                                    directions.               Some are non-directional/                 in a narrow cone.
                                                                                                                                                                  No beam angle                      omnidirectional                Narrower beam angles
                                                                                                                                                                                                   (emulating the light
                                                                                                                                                                                                      distribution of
                    415 lux                                                                   285 lux                                                                                              incandescent bulbs)


                                     160 lux                                     112 lux

                 Figure 5a                                        Figure 5b

                                                                                                                                                                    Full light                         Wide light                         Narrow light
                 Figure 5 Lumen and lux should not be confused. The light output of a lamp is measured in Lumen. Illumination levels                               distribution                       distribution                        distribution
                 of surfaces (in lux) are dependent on the lumen output of the lamp, but distance from the lamp and the beam angle
                 (how much the lamp concentrates its light) have to be taken into account.

                                                                                                                                                        Figure 6 Distinguishing non-directional and directional lamps. Beam angle is a feature of many types of
                                                                                                                                                        LED lamps, not just downlighter lamps.
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                  Figure 8 illustrates the lux levels delivered           Beam angle is also important in creating
                  by a variety of lamp specifications in an               the right level of task lighting and accent                                                                                               Beam Angle
                  example kitchen space (with a minimum                   lighting in rooms. If the incorrect lamps are
                  illumination target of 150 lux for the floor).          fitted in the wrong positions the necessary                                                         38°                           45°                           90°                          110°
                                                                                                                                                                   (each lamp illuminates        (each lamp illuminates        (each lamp illuminates         (each lamp illuminates
                  A variety of solutions work well, but some              task lighting or the desired effect from the                                              only about 15% of the         only about 25% of the             100% of the                    100% of the
                  may be impractical or unsuitable. Note that             lighting may not be achieved.                                                                 kitchen floor)                kitchen floor)                kitchen floor)                 kitchen floor)
                  for the higher beam angles (90o and 110o)
                                                                          In practice, the recommended levels for lux          220                                     1 lamp provides               1 lamp provides               1 lamp provides                1 lamp provides
                  each lamp illuminates the whole area and                                                                     lumen                                      111 lux                        80 lux                         21 lux                        14 lux
                  their individual lux contributions can be               in Section 6 should be relatively easy to            lamps                                     at floor level                at floor level                at floor level                 at floor level
                  added together to achieve the 150 lux                   achieve with domestic lighting. A number of          (note: this lumen output is too
                                                                                                                               low to qualify as low energy            To meet at least               To meet at least              To meet at least             To meet at least
                  target. For example, four lamps, each                   websites offer lumen to lux, and lux to              lighting in Part L)                   150 lux, 18 of these           150 lux, 8 of these           150 lux, 8 of these          150 lux, 11 of these
                  delivering 40 lux across the whole floor,               lumen conversions for different beam                                                        lamps are needed               lamps are needed              lamps are needed             lamps are needed

                  provide 160 lux overall. In this example the            angles and varying distance between light
                                                                          source and target surfaces. They also allow          420                                     1 lamp provides               1 lamp provides               1 lamp provides                1 lamp provides
                  90o beam angle lamps will need to be                                                                         lumen                                      213 lux                       153 lux                         40 lux                        27 lux
                  concentrated centrally over the floor area.             you to calculate the light coverage (m2) and         lamps                                     at floor level                at floor level                at floor level                 at floor level
                  In all cases the inclusion of different                 spread (m). A rule of thumb is to ensure that
                                                                                                                                                                       To meet at least               To meet at least              To meet at least              To meet at least
                  configurations of downlighters should not               the edges of the spread meet, but do not                                                   150 lux, 9 of these            150 lux, 4 of these           150 lux, 4 of these           150 lux, 6 of these
                  reduce the fire resistance of the ceiling: this         fall short (creating dull areas) or overlap                                                 lamps are needed               lamps are needed              lamps are needed              lamps are needed

                  should be checked with the downlighter                  (creating areas that are too bright).
                  manufacturer.                                                                                                625                                     1 lamp provides               1 lamp provides               1 lamp provides                1 lamp provides
                                                                                                                               lumen                                      317 lux                       227 lux                         59 lux                        41 lux
                                                                                                                               lamps                                     at floor level                at floor level                at floor level                 at floor level
                                                                                                                               (close to the maximum currently
                                                                                                                               available for downlighter lamps)        To meet at least               To meet at least              To meet at least              To meet at least
                                                                                                                                                                     150 lux, 9 of these            150 lux, 4 of these           150 lux, 3 of these           150 lux, 4 of these
                                                                                                                                                                      lamps are needed               lamps are needed              lamps are needed              lamps are needed

                  420 lumen lamp                                       420 lumen lamp                                                                             Figure 8 How many downlighters in a 4x4m kitchen? As the chart shows, it depends on the lumen
                                                                                                                                                                  output and beam angle of the lamps selected. Green choices may be the most economic, orange choices
                                                                                                                                                                  are intermediate and red choices may be uneconomic/impractical. The purple options will result in floor
                                                                                                                                                                  illumination levels that may be too bright for some people.
                                                                                                                                                                  This example is for a 4x4m kitchen with a 2.4m ceiling height and worktops with their own task lighting on two walls.
                                                                                                                                                                  A design illumination level of 150+ lux has been selected for the floor.

                        38°                                                   90°
                       beam                                                  beam                                      2,400
                       angle                                                 angle                                      mm

                  2.2m2 illuminated                                    18m2 illuminated
                     at 213 lux                                           at 40 lux

                 Figure 7 Importance of beam angle. These two low-energy lamps (with the same lumen output) generate
                 a quite different illumination level (lux) and light coverage area (m2) at floor level.

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                 Colour temperature – warm or cool effect?                                                                                    Colour rendering – bright or dull colours?
                 Initially many low energy lamps,                           For all uses in the home, warm white lamps                        Colour rendering is a measure of how            the home or if you want to ensure vibrant,
                 particularly LEDs, produced light with cooler              (close to 2,800K) are normally the most                           natural the colours of surfaces appear. It is   natural colours from low energy lamps.
                 colour temperatures – too stark for many                   suitable, though in kitchens and bathrooms,                       expressed by a colour rendering index (CRI)
                 uses in the home. But today low energy                     colour temperatures of around 3,000K may                          up to 100, see Figure 10. As tungsten           Colour rendering has been a critical
                 lamps are available which produce                          be preferred by some people.                                      incandescent lamps generated a full             performance consideration for
                 comfortable warm white light, similar to                                                                                     spectrum of visible light colour, and like      manufacturers of linear and compact
                 that produced by tungsten incandescent                     Non-incandescent lamps have to be tested                          daylight, have a CRI of 100, good colour        fluorescent lamps and high CRI values of
                 lamps. Figure 9 shows the colour                           for alignment with the colour temperature                         rendering could be taken for granted.           90-95 are available. Though a weakness
                 temperature scale used in lighting design.                 scale: they have what is termed a                                 However, low energy lamps do not all            with early LEDs, many now offer good or
                 It is based on the colour profile of light                 ‘correlated colour temperature’ (CCT). While                      provide the required level of colour            excellent colour rendering and CRI
                 emitted from an increasingly hot filament.                 they may match a point on the colour                              rendering and this is an important              values are included on packaging or
                 A reference point is the ‘warm white’ light                temperature scale, they achieve this with                         consideration in their choice. For most         manufacturers’ specifications. CRI is an
                 generated by a traditional tungsten                        spectral characteristics that are different                       domestic purposes a CRI of 80 or more is        important characteristic of domestic
                 incandescent lamp, with a colour                           from daylight, and this may affect the                            considered adequate, however a CRI above        lighting and it is worth comparing
                 temperature of 2,800K.                                     ability of a lamp to illuminate colours well.                     85 may be preferable for some activities in     samples from different manufacturers.
                                                                            For this reason, fluorescent and LED lamps
                                                                            are also rated for ‘colour rendering’.

                                                                                                                                                                                                                                 CRI = 100

                                                                                                                                                                                                                                 CRI = 75
                                                                                                                                              Figure 10 Good colour rendering
                                                                                                                                              brings out the vibrancy of colours
                                                                                                                                                                                                                                 CRI = 50
                                                                                                                                              in a home. As the colour rendering
                                                                                                                                              index (CRI) approaches 100, colours                                                CRI = 25
                                                                                                                                              appear more natural.

                   2,700K       Warm White          3,200k           Cool White        4,500K      Daylight White   6,500K

                 Figure 9 The standard international colour temperature scale
                 Image from

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                 Lumen maintenance – will lamps stay bright?                                                                          Rated life of LEDs – how long should they last
                 Lumen maintenance is concerned with how               This means that 50% of this batch of lamps                     ‘Rated life’ indicates how many hours of use    The life of an LED lamp is determined
                 long a lamp retains its lumen output. It was          is expected to maintain 90% (or more) of                       you can expect from a lamp. So an LED           by a range of factors related to proper
                 not an issue for incandescent lamps                   the original lumen output after 35,000                         product with a rated life of 30,000 hours,      installation and use. When selecting LEDs,
                 because these typically failed suddenly               hours of use. More accurate indications of                     used for a typical 1,000 hours a year, could    check that there are no limitations or
                 before there was any noticeable                       lumen maintenance will become available                        last for 30 years. Note however that at 30      conditions on the warranty that conflict
                 deterioration in light output. For a long-            in future years, but in the meantime it is                     years, 50% of this particular product will be   with the intended installation of a
                 lasting lamp it’s crucial to know how well it         recommended that lamps with the highest                        functioning below its lumen maintenance         particular product. Some manufacturers
                 sustains its claimed lumen output. Indeed             levels of lumen maintenance (i.e. 90% or                       threshold, including some that may have         have strict conditions to qualify for their
                 for LEDs (which are more likely to fade than          more) are selected for domestic use. Lumen                     failed completely. The lumen maintenance        warranties. These may include limits to
                 to fail completely) a drop in lumen output            maintenance is one of the most important                       value (or code), see above, tells you how       total number of annual operating hours and
                 below a particular level marks the end of             performance measures for LED lighting and                      serious the light depreciation could be for a   maintenance considerations. You should
                 the lamp’s life (see rated life, below).              ideally you should ensure that                                 particular product. Always view rated life      check that the warranty applies to all parts
                                                                       manufacturers’ claims are backed by                            and lumen maintenance values together.          of a lamp, including the integral drivers,
                 LED testing methodology is evolving.                  independent test data. Most manufacturers                                                                      which may be less durable than the light
                 Currently lumen maintenance is being                  provide lumen maintenance figures in their                                                                     emitting diodes themselves.
                 estimated by many manufacturers from                  technical specifications and these may be
                 tests running for 6,000 hours. Their                  coded as below. For illustrative purposes
                 estimates of lamp life are based on the               the decline in output for a 420 lumen lamp                     Operating temperature – don’t let them overheat
                 expected deterioration of the                         is shown for each code rating in Table 2.
                 semiconductor within the LED and this                                                                                LEDs generate far less heat than                These vary and you should seek advice when
                 enables them to offer lumen maintenance                                                                              incandescent lamps, however about 50% of        LEDs are to be recessed or incorporated in
                 projections in technical specifications.                                                                             energy used by an LED may be converted          places where there is limited air flow. Often
                 A lamp might be described as having:                                                                                 into heat. To avoid overheating of the          a maximum ambient air temperature of
                 More than 90% lumen maintenance by                                                                                   semiconductor material and to operate           40oC is specified and this can easily be
                 50% of lamps at 35,000 hours.                                                                                        efficiently, LEDs have integral heat sinks.     exceeded if LEDs are inappropriately
                                                                                                                                      However, it is important that the air           installed. Special care should be taken when
                                                                                                                                      temperature around an LED should be             downlighters are recessed into insulated
                                                                                                                                      within limits specified by the manufacturer.    ceilings (see page 06).
                 Lumen maintenance: What the lumen maintenance codes mean in practice.                     Table 2

                   Lumen         Code    Lumen maintenance for an example lamp,
                   maintenance           initially rated at 420 Lumens:                                                               Drive current – don’t overload
                   >90             9     Steady decline to ≈378 lumens during life*                                                   For proper operation of LEDs, the power         higher an LED is driven the brighter it will
                   >80             8     Steady decline to ≈336 lumens during life*                                                   supply and internal electronics must            be but this may impact on lifetime and
                   >70             7     Steady decline to ≈294 lumens during life*                                                   provide a well-controlled DC drive current.     efficiency, and all controls (particularly
                                         * Figures above show likely average decline for                                              Drive current affects LED operating             dimmer switches) must be rated
                                         a lamp manufactured to a particular Lumen
                                         Maintenance Code.                                                                            temperature and thus its lifetime and light     appropriately for the fittings being used. If
                                                                                                                                      output. Normally, products quoting a drive      replacing existing lamps with LEDs, dimmer
                                                                                                                                      current of 350mA are suitable for homes,        switches will need to be replaced with
                                                                                                                                      although the values can be higher. The          suitable products or de-rated.

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                 Cost – Homeowners’ perspective                                                                 6. Lighting guidance for the home
                 Until recently, the upfront cost of             increasingly seen by the public as the                             Careful design of electric lighting will          lighting effects for different situations.
                 purchasing LED lamps has been a major           technology of choice, and many people are                          ensure that the right amount of light can be      Well-designed lighting will be inherently
                 barrier to wide-scale use. For homeowners,      investing in them. Although initial outlay                         switched on conveniently where and when           easier to use and more likely to be operated
                 however, the recent price reductions,           might be a little more than other lighting                         it is needed. It avoids any over-lit areas, and   in an energy-efficient way.
                 coupled with greater awareness of the other     options (Figure 4), LED lamps soon generate                        gives control and flexibility to create
                 advantages of LED lighting has changed the      financial savings for homeowners because
                 picture quite dramatically. LED lighting is     of their very low use of energy.

                                                                                                                Overall approach – three levels of lighting
                                                                                                                General lighting                         Task lighting                         Accent lighting
                 House builders’ perspective                                                                    should provide satisfactory              is needed for specific activities     contributes to the ambience of a
                                                                                                                minimal lighting levels in rooms.        within the home such as reading,      home. As with task lighting lamps
                 While LEDs remain more expensive to             as standard. The current downward              Decide on the target illuminance         food preparation and home             (or socket outlets) are needed in
                 purchase than CFLs, and while the Part L        trajectory for LED lamp prices, if it          levels required (lux). In living         working. Lamps must be carefully      the right places to emphasise
                 requirements allow CFLs as part of              continues, will soon see very little           rooms and bedrooms, in particular,       selected, correctly positioned and    architectural features, furniture
                 compliance, house builders have no direct       differentiation between the price of LEDs      allow some flexibility (through          controlled. Lamps or socket           and ornaments. Accent lighting is
                 financial incentive to install LED lamps.       and CFLs and at that point it seems likely     control settings/dimmers) so that        outlets are needed in the right       a more personal consideration,
                 Some house builders however are offering        that the majority of house builders will       occupants can raise or lower the         places to give flexibility in the     with spotlight through to flood
                 LEDs as an option for home buyers who           switch and join those who have already         general lighting around the target       availability of task and accent       light effects being appropriate
                 request them, and some are offering them        started to adopt LEDs.                         level. Design to the higher end of       lighting. Task lighting may be        depending on circumstances.
                                                                                                                lux ranges in homes intended for         needed at different levels,
                                                                                                                older people, who generally              depending on the task. Also, colour
                 Specifying good quality LEDs                                                                   appreciate higher levels of general      rendering of the light is very
                 Due to rapid developments in LED lighting       operated under an appropriate quality          lighting. A minimal level of             significant for some activities.
                 over recent years, many lighting                assurance regime, accredited to ISO/IEC        general lighting is required for
                 manufacturers inexperienced in the              17025: General requirements for the            safe movement around the home,
                 production of quality LEDs have introduced      competence of testing and calibration          particularly on stairs, but sufficient
                 products to the market. Product quality can     laboratories. Accreditation to this standard   general light is considered to be
                 vary significantly. Good quality products,      should be awarded by an accrediting body       important for general well-being.
                 which meet the criteria suggested in this       that operates within the charter established
                 guide, can be selected by ensuring that all     by the International Laboratory                                    For each of these levels of lighting, controls    Similar patterns of control can be
                 appropriate conformity and testing              Accreditation Cooperation (ILAC). In the UK                        can provide a range of lighting options.          considered in other rooms, with dimmers
                 documentation is in order. This should be       this is the United Kingdom Accreditation                           So in a kitchen there could be separate           providing a range of lighting ambience in
                 freely available from the manufacturer.         Service (UKAS).                                                    controlled circuits for:                          lounges, dining rooms and bedrooms.
                 Ideally, manufacturers’ claims should be        It is important to evaluate manufacturers’                                                                           Advanced controls, sometimes controlled
                 backed by independent test data.                                                                                   • general lighting (typically ceiling             by a mobile phone or tablet ‘app’, which
                                                                 claims on a consistent basis – so when                               downlighters)
                 If manufacturers’ own test data is supplied,    requesting LED performance specifications                                                                            allow remote adjustment of the amount of
                                                                                                                                    • task lighting (typically positioned under       light and its colour are now emerging.
                 it is recommended that they also supply         always ask for data that has been measured                           the wall units) and
                 evidence that confirms their test facility is   in compliance with the latest IEC/PAS                                                                                Lighting is becoming established as a
                                                                                                                                    • any accent lighting (for example inside         lifestyle statement and homes which
                                                                 documents.                                                           units or around pelmets).                       incorporate new and innovative lighting
                                                                                                                                                                                      systems are perceived to have a marketing
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                                                             Individual rooms
External lighting                                            Hallways                                                            Living rooms                                     Dining rooms
The selection of external lighting will                      Flush ceiling fittings can maximise                                 Living rooms need a relaxed atmosphere           Lighting can be used to create different
largely depend upon its purpose and the                      headroom in what is often a small area                              and some flexibility in lighting level and the   moods. A wash of light over one wall or the
way it is to be used. Where lighting is                      and downlighting is often the most                                  position of lighting. Controls should ensure     ceiling can provide a background level of
required in the garden, for example to light                 appropriate solution. Since hallways are                            that living room floor illumination can be       lighting against which a variety of lighting
a path while it is in use, LED products are                  often lit for long periods, the use of LED                          set at around 100-150 lux with the               effects can be achieved using portable
ideal.                                                       lighting will maximise energy savings.                              flexibility to be reduced to subdued levels      luminaires. There are many LED products
                                                             A lux level of between 100-150 is                                   of around 60 lux. This may require a variety     that lend themselves well to creating this
Building Regulations require external                        recommended at floor level.                                         of light sources. Avoiding glare is also         ‘wash’ effect, that provides comfortable
lighting products to include a photocell (to                                                                                     important and wall-mounted uplighters can        indirect lighting.
stop the light being used in daylight). With                 Stairs and landings                                                 meet this need.
less efficient lamps, the Building                           As in the case of hallways, flush fittings are                                                                       Lighting specified in dining rooms should
Regulations require that the external lamp                   useful when headroom is limited. To provide                         The living room’s long hours of use will         have a colour temperature within the limits
is controlled by a presence detector, to                     adequate lighting stairs may require                                mean that LED lighting will achieve              of 2,700K-3,000K, and provide about 150
switch off the lamp when no-one is in the                    luminaires either along them, above them,                           significant energy and cost savings, even        lux at floor level. In many homes, dining
illuminated area. With low energy lamps,                     or in close proximity on the landing. To                            when compared to CFLs. Good ambient              room tables, are used for variety of
the regulations are more relaxed, and allow                  avoid falls on stairs, lighting should be                           background lighting can be supplemented          activities as well as dining. For this reason
manual control of the lighting.                              operated by two-way switching situated at                           by portable fittings such as table or            some flexibility in lighting for the dining
                                                             both the top and the bottom of flights.                             standard lamps, which provide the higher         table top is recommended: it should be
In recent years considerable levels of light                                                                                     localised levels of lighting required for        possible to provide flexibility for dining
pollution have been generated by high                        Lighting should be positioned to ensure that                        reading or other detailed activities.            between 150 and 200 lux, and between
powered incandescent external                                stairs are easily visible (by providing                                                                              400 and 500 lux for situations when the
floodlighting, typically in the 200-400W                     contrast in lighting between treads and                                                                              table is used for other tasks, such as
range. These are expensive to run and                        risers). Ideal colour temperature for lighting                                                                       homework and hobbies. Dining room
provide far more light than required. In                     on stairs and landings is around 3,000K and                                                                          lighting should have excellent colour
domestic settings a 150W lamp is generally                   lighting for stair treads should be at least                                                                         rendering.
sufficient but best practice would involve                   100 lux. Lighting on stairs and landings
specifying an LED floodlight, where a                        (including daylight as well as artificial light)
20-30W product should be sufficient.                         should be designed to minimise glare.

     Elderly and partially-sighted people
     need enhanced lighting
     If you are developing a lighting scheme for older
     people use the higher end of lux ranges
     recommended in this section and consider
     providing a greater number of point light sources
     for activities. Seek specialist advice (see further
     information) if you are making lighting provision for
     partially-sighted occupants in line with
     manufacturer’s recommendations.

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                 Kitchens                                         Bedrooms                                                                  Bathrooms                                      Studies and home offices
                 The detailed tasks being carried out in          Bright central light sources, while providing                             Although bathrooms are not lit for long        Harsh lighting can create glare on computer
                 kitchens require high levels of lighting,        good general light levels, can create glare.                              periods, the use of low energy long-life LED   screens and paper-covered desks. This can
                 particularly as sharp tools will be in use.      This can be reduced by directing light onto                               lighting can be particularly appropriate for   be avoided by arranging diffuse background
                 For kitchen floors, appropriate illuminance      the wall surfaces. Providing a separate                                   enclosed fittings where lamps may be           lighting. Dedicated wall uplighters can be
                 levels are 150-200 lux for floors and around     circuit specifically for bedside lighting, with                           difficult to replace. LED downlights are       used to create a general wash of light. Task
                 400 lux at worktop, hob and sink levels          lighting socket outlets and two-way                                       particularly suitable for bathroom lighting    lighting can be provided by using portable
                 (downlights placed under units can achieve       switching will help ensure lights are not left                            where they can be positioned to provide        lamps and there is an increasing range of
                 these levels and, if the kitchen is centrally-   on unnecessarily. Lighting levels in                                      lighting where it is needed, for example       LED desk lamps on the market.
                 lit, prevent people having to work in their      bedrooms should be controllable, with                                     over the bath and shower. Aim for good task
                 own shadows).                                    flexibility to provide subdued levels of 60                               lighting levels around bathroom mirrors        Studies and home offices require good levels
                                                                  -100 lux at floor level and a maximum of                                  and illumination levels of 250-300 lux for     of lighting with between 400 and 500 lux
                                                                  about 150 lux. There should be provision of                               bathroom floors.                               for task lighting on desks. If more intricate
                                                                  good task lighting for activities such as                                                                                work is being undertaken, aim for 750 lux.
                                                                  reading, offering localised illumination of                               When specifying bathroom lighting, take
                                                                  up to 400 lux. Good colour rendering is an                                care to check how far from a water source
                                                                  important consideration in bedrooms to                                    it can be fitted. A bathroom is divided
                                                                  help in the choice of clothes for example.                                into zones 0 to 3 and bathroom lighting
                                                                                                                                            is marked with the zone in which it can
                                                                                                                                            be used.

                                                                                                                                            It is recommended that general bathroom
                                                                                                                                            lighting and task lighting (eg lighting for
                                                                                                                                            mirrors) are on separate circuits.

                                                                    Colour temperature
                                                                    In the past for rooms that used to have a functional
                                                                    use, such as kitchens and bathrooms, it was
                                                                    considered right to have cooler colour temperatures
                                                                    in the region of 3,000 to 3,500K. This may still be
                                                                    suitable for some internal designs, and be favoured
                                                                    by some householders. However for modern living
                                                                    the trend is to provide lighting within the ‘warm
                                                                    white’ light range 2,700-3,000K throughout the

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