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Communal Lighting:

A guide to lighting upgrades in residential buildings

“The installation of LED light fittings in communal areas of housing can lead to very significant improvements in lighting levels, maintenance of light levels and quality of light, while at the same time generating energy savings.”

Energy Saving Trust, Lit Up: An LED Field Trial

Corridors ~ Stairwells ~ Lobbies ~ Lounges ~ Amenity Spaces ~ External ~ Car Parks

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Contents 1 Introduction .................................................................................................. 3

2 Key Literature .............................................................................................. 4

3 Key Benefits ................................................................................................ 5

3.1 Total Cost of Ownership ......................................................................................... 5

3.2 Ambience ................................................................................................................ 5

4 Key Considerations...................................................................................... 6

4.1 Lamps ..................................................................................................................... 6

4.2 Automatic Switching Control Options ...................................................................... 6

4.3 Design Principles .................................................................................................... 7

5 Cost considerations – worked example ....................................................... 8

5.1 Install, Energy and Lifetime Costs .......................................................................... 8

5.2 Worked Example: CFL Bulkheads – long-term cost comparisons .......................... 8

5.3 Conclusions ............................................................................................................ 8

6 Design Example .......................................................................................... 9

6.1 Introduction ............................................................................................................. 9

6.2 Design model .......................................................................................................... 9

6.3 Results .................................................................................................................... 9

7 Case Study ................................................................................................ 10

8 About Sustain ............................................................................................ 11

8.1 Our Services ......................................................................................................... 11

8.2 Accreditations ....................................................................................................... 11

Appendix 1: Residential Communal Lighting Survey Sheet ................................. 12

Appendix 2: Glossary of Terms ........................................................................... 14

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1 Introduction This summary design guide is intended to raise awareness and inform stakeholders on key considerations during lighting refurbishments in communal residential areas. Appendix 1 offers a practical and simple survey sheet to help identify the opportunity and start to form a business case for its implementation. These may include private and social housing, residential homes for the elderly, nursing homes, residences at a university, school boarding houses, children’s homes, NHS staff accommodation and alike. Lighting typically accounts for 30% of a sites electricity consumption. Specifying the optimum lighting, controls and design can result in improved living conditions for the residents as well as significant energy and cost savings (operating and maintenance).

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2 Key Literature

The Energy Saving Trust Lit Up: an LED Lighting field trial Published in 2011 this remains the best source of independent research into the impacts of LED lighting within social housing. Tested across 35 sites the trial reported;

Significantly improved lighting Reduction in energy consumption Lower maintenance costs

In the 5 years since this study LED technology has taken a huge leap forward, as discussed later in this guide. http://www.energysavingtrust.org.uk/sites/default/files/reports/LitupanLEDlightingfieldtrial.pdf

Chartered Institute of Building Services Engineers (CIBSE) Lighting Guide 9: Lighting for communal residential buildings A comprehensive best practice guide covering all aspects of lighting design specifically in communal residential buildings. Incorporates the advances in lighting controls, use of daylight and is relevant to both new and existing projects. http://www.cibse.org/Knowledge/knowledge-items/detail?id=a0q20000008I7kJAAS £66 for non-CIBSE members (pdf)

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3 Key Benefits

3.1 Total Cost of Ownership

3.1.1 Maintenance

LED lamps last four times longer than their equivalent compact fluorescent and fluorescent equivalents, reducing replacement and call out associated costs. An LEDs life is further extended when combined with controls that reduce their operating hours. In fact most LED manufacturers will now offer a 5 year product warranty which is longer than the life expectancy of current units.

“Raven have to replace, on average, 4 light bulbs per day in the communal areas of our properties. This costs approximately £20,000 per year, in addition to the man hours and vehicle costs.”

Raven Housing Trust

3.1.2 Energy Costs

LED technology is improving at a rapid rate but at the time of writing 25-60% savings are readily achievable from a like for like replacement of typical communal lamp fittings. Further energy and carbon reductions can be achieved through best practice design incorporating natural light, controls and re-designing the lamp layout aided by computer modelling.

An 87% energy saving was realised at Homes in Sedgemoor’s West Street site through the retrofitting of LED lamps with integrated occupancy linked controls, whilst improving the quantity and quality of light for the residents.

Sustain Case Study: Homes in Sedgemoor

3.2 Ambience

Lighting plays such an important role in the functionality and enjoyment of a space and LEDs are a big winner here to. Now coming in a range of different colour temperatures LEDs are able to produce a greater sense of daylight indoors. This is healthier and more appealing to the human eye, especially where visual impairment may be an issue.

The impact of the LED lighting on colour temperature is also clear. The cooler, brighter light has greatly enhanced the ambience within most of the sites. Colour rendering has also improved, so that colours appear much sharper.

The Energy Saving Trust

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4 Key Considerations 4.1 Lamps

Lamp Life The typical life of different lamps range from 2,000 hours (halogen spot) to 50,000 hours for an LED. With operating hours of residential facilities typically exceeding 4,000 hours annually, the correct selection can greatly reduce maintenance costs in the future. Luminous Efficacy This is the measure of lumens per watt. By maximising the luminous efficacy the power rating/costs will be minimised. However, a balance with other characteristics should be struck to ensure the lighting design meets all the needs of the building and its occupants. Colour Colour temperature and colour rendering are both key considerations to ensure the correct consistency, ambiance and functionality of different spaces is achieved. Colour temperature is the colour of the light itself (cool, warm etc). Colour rendering refers to how the light reveals the colours of the objects it falls upon. Types The most common types of lamp found in residential communal buildings include incandescent, tungsten and fluorescent/compact fluorescent (CFL). Whilst these lamps provide sufficient light outputs in a range of applications, their luminous efficacy can be as low as 13W per lumen and have considerably shorter life expectancies when compared with modern LED alternatives. Luminaire A luminaire is defined as the apparatus containing the light source (lamp) and its main function is to support the lamp, protect it from damage and direct the light. Firstly the luminaire must be fit for purpose; resistant to local environmental conditions (IP rating), impact resistant (IK rating) and efficient at distributing light effectively (Light Output Ratio (LOR)). Once these factors have been addressed the appearance and integration of controls and emergency features should be considered to optimise the design.

4.2 Automatic Switching Control Options

Presence and absence detection Lighting will automatically be switched on and/or off when anyone enters and leaves the room (according to a pre-set time). Where some lighting is required at all times base lux levels will be maintained. Absence only detection requires manually switching ‘on’ but minimises parasitic power.

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Daylight control A photoelectric cell (PEC) monitors the level of daylight, switching ‘on’ when the daylight fades below a trigger point maintaining a consistent lighting level and resulting in potential savings of 40-50%. Daylight control with presence detection Combining the two types in the correct settings will yield maximum savings. Lighting management systems From basic time clock controls to more sophisticated single and multi-room control systems, separate or integrated with building management system.

4.3 Design Principles

First and foremost the lighting should meet the functional needs of the building and its occupants. This includes: ensuring health and safety considerations are addressed, optimising comfort levels and meeting the correct lighting levels that meet the requirements of the tasks performed in each space. Energy costs constitute a significant proportion of the operating costs of communal residential buildings. This makes designing and managing lighting effectively an important economic consideration. Apply good lighting principles:

use daylight wherever possible and practical select efficient luminaires and use them effectively Avoid over-lighting. Ensure luminaires are not left on when not needed—investing in control systems is

a cost-effective method of achieving this. Ensure effective maintenance, which minimises lumen depreciation. Exterior lighting should be monitored, including regular routine checks to ensure

control systems such as photoelectric sensors and time-clocks are operating correctly.

Function

Lifetime

CostDesign

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5 Cost considerations – worked example 5.1 Install, Energy and Lifetime Costs

Selecting a lighting design based on the lowest initial installation costs can often lead to a false economy. Due consideration should be given to the operating and maintenance/replacement costs over a longer period to determine the most economic design specification to meet your requirements. Below is a worked example to demonstrate this point.

5.2 Worked Example: CFL Bulkheads – long-term cost comparisons

A housing block currently has 20 CFL bulkheads in the corridors and they are due for replacement. A comparison between CFL and LED lamps and different control solutions is being considered, both have identical lumen output and colour properties. They pay 12p/kWh for electricity.

20 Year Forecast

Current vs Proposed Lighting (20 units)

Annual Operating

Hours

Lifetime (Yrs)

Total Energy

Cost

Energy Saving

(%)

Install and Replacement

Costs

Total Cost (Energy +

Install)

Total Cost

Saving

Total Saving

(%)

28W Bulkhead 4000 3 £5,376 £7,560 £12,936 £ - 17W LED Bulkhead 4000 13 £3,264 39% £3,230 £6,494 £6,058 50%

18W LED Bulkhead with Occupancy Sensor

2500 20 £2,160 60% £1,710 £3,871 £8,681 70%

20W LED Bulkhead with Daylight/Occupancy Sensor

1500 33 £1,440 73% £1,990 £3,431 £9,121 73%

5.3 Conclusions

CFL’s whilst cheaper to install, would cost at least double that of LEDs over 20 years due to a lower life expectancy. On a like for like basis LED fittings reduce energy consumption by nearly 40% with no detrimental impacts on output or colour. Occupancy controls extend the life of the lamps through a reduction in operating hours, resulting in a further reduction in replacement

costs as well as annual energy/cost savings. Combination controls cost more initially but this is offset by further reductions in operating hours and therefore total costs (73% total

saving over 20 years).

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6 Design Example 6.1 Introduction

In the example below a corridor containing eight CFL bulkheads is due to be upgraded. The lighting is currently on for 12 hours a day, although the corridors are only occupied on average for 3 hours. The owner pays 12p/kWh for their electric. A lighting design model has been used to ensure lighting levels are maintained.

6.2 Design model

Through computer modelling of the corridor conditions it is possible to determine the optimum number of fittings required to achieve desired lighting levels. In this instance it is possible to reduce the number of fittings by 25% resulting in both lower power ratings (53% reduction) and material costs. There would be additional remedial costs but these would quickly be offset. Pre: Eight 28.7W CFL Bulkheads with a specific connected load of 12.76W/m2

Post: Six 18W LED Bulkheads with a specific connected load of 6.0W/m2

6.3 Results

In this example combining the reduction in number of fittings, with increased lamp and luminaire efficiency and additional occupancy dimming controls results in an 85% reduction in electricity consumption with no detrimental impact on lighting levels.

100%

Load (W) Operating

Hours 10%

Load (W) Operating

Hours Total kWh Cost

Pre 229.6 4380 - - 1,005.65 £120.68

Post 108 1095 10.8 3285 153.74 £18.45

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7 Case Study

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8 About Sustain Established in 1997, Sustain is a leading UK energy and carbon management company dedicated to providing cost and carbon efficiency through improved design, delivery and management of energy resources in public and private sector organisations. As a result, clients benefit from improved performance, reduced costs, a cleaner brand and reputation, legal compliance and a long-term resilience to changes related to energy and climate risk. With experts focusing on key sectors where the largest reductions can be made, Sustain’s track record within utilities, commercial and industrial buildings, housing, manufacturing and the public sector, is second-to-none. Sustain is proud to be a 100% employee-owned business.

8.1 Our Services

Compliance and Standards Energy Management Energy Systems Engineering Products and Technologies

For more information and case studies please visit www.sustain.co.uk or contact James Walker (0117 403 2667) james.walker@sustain.co.uk

8.2 Accreditations

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Appendix 1: Residential Communal Lighting Survey Sheet Next time anyone is on site complete and return this form to; james.walker@sustain.co.uk to receive a free no obligation, high level, lighting business case.

Instruction:  Collect and document communal lighting information whilst on‐site to inform of potential for LED Lighting upgrades. Completed document to be filled in and returned along with photographs of each type of light and general areas. Comments: (Please record anything you think may be important e.g access issues above stairs etc) 

Site Name:  Date:   

Office to complete for energy calculations 

Lamp Operating Hours per week   

Electricity Cost (£/kWh)   

Area   Lighting Type 1  Q'ty  Photo Lighting Type 2  Q'ty Photo Lighting Type 3  Q'ty Photo Occupancy Controls? 

Good Levels of Daylight? 

% not working 

Corridors                                     

Stairwells                                     

Common Areas                                     

External                                     

Car Park                         

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Common Types of Lighting

Linear Fluorescent Tubes Fluorescent Panels (4ftx2ft, 2ftx2ft) Bulkheads (2D Compact Fluorescent)

Floodlights (Halogen, Sodium) GU10 Downlights Compact Fluorescent

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Appendix 2: Glossary of Terms Lamp A device for giving light. Refers specifically to the emitter rather than the holder. Luminaire A complete electric light unit, consisting of the lamp and its holder. Lumen The unit of luminous flux: a measure of the total quantity of visible light emitted by a source. Lux The SI unit of illuminance, equal to one lumen per square metre. Parasitic power The power consumed by the sensor even when the luminaire is shut off. Lumen depreciation Lumen depreciation is the luminous flux lost over time, and thus the complement of lumen maintenance. Lumen maintenance compares the amount of light produced from a light source or from a luminaire when it is brand new to the amount of light output at a specific time in the future.