Low Energy Lighting at BowlplexBy Eric R Hawkins
Posted on 28 August, 2007
LOW ENERGY LIGHTING
Replacing a section of halogen lighting at Bowlplex Ltd, Tower Park, Bournemouth
Bowlplex Ltd has sixteen 10 Pin Bowling Centres across the
Powertech Solar Ltd was recommended to Bowlplex by The Dorset Resource Efficiency Club which helps members to develop skills in waste minimisation, energy reduction etc. by offering them mentors and specialist help. For more information about the Club please visit: http://www.envirowise.gov.uk/page.aspx?o=212765. Powertech Solar Ltd has many years’ experience in providing solutions to the problems associated with energy waste across the world, and supply a wide range of alternative energy related products and system designs that can help reduce all of our resource bills.
Areas where Powertech Solar identified where those energy savings could be made at Bowlplex:
1. 180 x 35 Watt Halogen spotlights dotted across the suspended ceilings;
2. 40 x 50 Watt Halogen spotlights located in the amusements around the floor area
3. Two electrically heated 200 litre hot water tanks supplying hot water to the kitchen and toilets. There were no time clocks visible, indicating that these were running 24hrs per day to a set temperature;
4. The air conditioning system runs flat out during hot summer days, trying to lower the temperature in this large building when busy;
5. The roof could be insulated to help cool the building in summer.
Powertech Solar’s recommendations:
1. To replace all the existing halogen light bulbs with the latest super bright micro CFL Suntech Solar range supplied by Powertech Solar;
2. To install three Thermaltricity ducted air source heat pumps within the roof space between roof and suspended tiles. These are to be suspended in the voids where heat builds up, to draw this ambient air into the evaporators and convert it for heating water up to 55°C.
3. This would simultaneously provide cooling in the space between the ceiling and roof reducing the work of the air conditioning system;
4. To apply liquid thermal insulation across the exterior of the roof to deflect the Sun’s heat thereby reducing heat passing through the roof space bringing considerable savings.
STAGE ONE - LIGHTING
Halogen lighting originally in place at Bowlplex Ltd,
Ÿ 35 Watt halogen bulbs dotted across ceilings (180 bulbs)
Ÿ 50 Watt halogen bulbs in amusement boxes (40 bulbs)
Estimated costs before changing lighting:-
|
Electricity used to power 180 x 35 Watt halogens and 40 x 50 Watt halogens running 18 hours per day 365 days a year @ £0.12p per kWh |
£0.12p per kWh |
£6,525.00 |
|
The 35 Watt halogen bulbs each have a life of 1,000 hours and are therefore replaced 6 times per year and cost £1.30 each, therefore total annual cost is: |
£1.30p each |
£1,404.00 |
|
Annual cost of replacing 50 Watt halogen bulbs at £1.30 each: |
£1.30 each |
£312.00 |
|
Replacement cost of transformers (based on £12.80 each assuming that transformers last 3 years): |
£12.80 each |
£768.00 |
|
Annual labour costs involved in changing, say, 2-3 light bulbs per day (based on half and hour per day at £10.00 per hour): |
£5.00 x 365 days |
£1,825.00 |
|
Estimated cost of air conditioning use to counter heat generated by lighting1 |
|
£1,000.00 |
|
Total: |
|
£11,834.00 |
1The amount of heat generated by these 220 halogen bulbs adds to the cost of running the air conditioning, as yet we do not know what this added cooling cost is, but for this exercise we have allowed £1,000.00 given that 90% of the energy used by halogens is converted into heat, which is adding to the heat load of the complex.
Estimated costs and pay back after changing current light bulbs:-
The Suntech Solar CFL bulbs have 8,000 hours of life (as opposed to 1,000 hours of life for halogens) requiring replacement every 14 months as opposed to every 2 months, thus reducing replacement and labour costs dramatically.
New low energy lighting to replace halogen lighting:
Ÿ 7W CFL spotlights (type 1) to replace 35W halogens (180 bulbs)
Ÿ 7W CFL spotlights (type 2) to replace 50W halogens (40 bulbs)
Using the same quantities and electricity cost as above but instead using the new Super bright Suntech Solar CFL spotlights the following figures were calculated:-
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Electricity cost to run 180 x 7W CFL spotlights = 1,260 W (1.26kWh ) x 18hrs a day = 22.68kWh x 364 days a year = 8,255kWh @ £0.12p per kWh |
£0.12p per kWh |
£990.60 |
|
Electricity cost to run 40 x 7W CFL spotlights = 280 W (0.28kWh) x 18 hrs a day = 5.04Kwh x 364 days a year = 1.839Kwh @ £0.12p per kWh |
£0.12p per Kwh |
£220.75 |
|
Replacement cost of the 220 CFL 7 W spotlight based on cost per bulb @ £2.50 each including transformer |
£2.50 each |
£550.00 |
|
Estimated cost of air conditioning to counter heat generated by lighting is now halved (as CFL bulbs produce half the heat of halogens): |
|
£500.00 |
|
The initial change over labour cost to replace all 220 bulbs based on 2 days @£10.00 an hour |
|
£160.00 |
|
Total: |
|
£2,421.35 |
PAY BACK
Current annual cost of running halogen bulbs - £11,834.00
Switching to new Suntech Solar CFL bulbs - £2,421.35
Daily running costs for halogens is - £32.42
Daily running costs for Suntech Solar CFL is - £6.63
Annual savings based on £25.79 (daily saving) x 365 days a year is: £9,413.35
Payback figures based on the above calculations works out at: 48 days
This calculation is based on the energy saved between the two bulb types
STAGE TWO – WATER HEATING
To install three Thermaltricity ducted air to water heat pumps within the roof space between roof and suspended tiles. These are to be suspended in the voids where heat builds up, to draw this ambient air into the evaporators and convert it for heating water up to 55°C. This would simultaneously provide cooling in the space between the ceiling and roof, thus reducing the work of the air conditioning system. These are to be installed later this year.