www.gavinhegarty.com
  • home
  • ENERGY ASSESSOR
    • AIR LEAKAGE SURVEY
    • THERMAL BRIDGE ASSESSOR
    • EPCs & ENERGY ASSESSOR
    • THERMAL CAMERA SURVEY
    • CODE FOR SUSTAINABLE HOMES ASSESSOR
    • DOMESTIC REFURBISHMENT ASSESSOR
  • HEALTHY DESIGN
  • VENTILATION
  • CASE STUDIES & INFO
    • 3 BED SEMI - 1990'S
    • 3 BED SEMI - 1960'S
    • 3 BED TERRACE - 1930'S
    • AIR TIGHTNESS IN EXISTING DWELLINGS
    • DAMPNESS AND CONDENSATION
    • GRANTS FOR BOILER REPLACEMENT
    • HOW ENERGY EFFICIENCY CREATES JOBS
    • HOW THE EPC EFFECTS HOUSE PRICES
    • LOW ENERGY LIGHTING
    • PHOTOVOLTAICS
  • CONTACT & PEOPLE

low energy lighting

From 2007 LED Lights started competing with Compact Fluorescent Lights in the domestic market but were generally expensive and had poor colour rendering. As with all new technologies, a couple of versions and years later, the prices have come down and the quality has gone up to make them worth consideration.
replace light bulbs & save £85 a year
Old style incandescent light bulbs up to 60W, can now be replaced with LED bulbs for £7 to £12 each. The LEDs will come on instantly and will reduce your lighting costs from £100 a year to under £20. They will pay for themselves within 2 years and will last up to 25 years.

10 x 60 watt old style light bulbs will cost £103.80 a year.
10 x 10 watt LED light bulbs will cost £17.30 a year.
Also factor in changing standard dimmers to LED dimmers at around £20 each if required.
lifespans
incandescent light                      1000 hours
compact flourescent light           8000 hours
LED light                                  25000 hours
colour temperature light bulbs
light bulbs
old style incandescent    compact flourescent           LED
light bulb                          light bulb                            light bulb

light fitting                            cost per year     lumens
100 watts (old style light bulb)           £17.30            1600
75 watts (old style light bulb)             £12.98            1100
60 watts (old style light bulb)             £10.38              800
50 watts (halogen downlighter)          £  8.65             600
15 watts (CFL light bulb)                    £  2.60             800
10 watts (LED light bulb)                    £  1.73             800
9 watts (LED downlighter)                  £  1.56
              600
5 watts (LED downlighter)                  £  0.87               350

change 12 halogen downlighters to LED and save £85 a year
The typical downlighter is a 50 watt halogen GU10.
It costs about 80p to buy and £8.65 a year to run.
The LED equivalent is a 9W GU10.
It costs £6-12 to buy and £1.56 a year to run.
The LED downlighter will pay for itself in under 2 years and lasts up to 25 years.

things to note
You may need to change your dimmer to an LED dimmer.
A standard dimmer may have a power rating of 40-60 watts
whereas 4 x 5W LED lights will only use 20 watts. A new LED dimmer will cost around £20.

Most rooms using downlghters are overlit and probably can be changed to 5W LED's with lower light outputs of 350 lumens.

LT lighting have an 11 watt LED light bulb (equivalent to 75 watts) that gives 1150 lumens and costs £16
colour temperature
A warm white similar to the old tungsten light bulbs is about 2700K. Cooler lights such as used in bathrooms and kitchens have a temperature around 5000K.
Please note your body clock is affected by the colour of the light. Cooler colours around 5000K are closest to the colour of sunlight at noon. Warmer colours around 2700-3000K are closer to sunlight at dawn and dusk.
Brushing your teeth under a cool blue light therefore is not the best preparation for sleep as your body clock will be thinking it is mid day making it difficult to get to sleep.

gu10 led light bulbs
            halogen GU10 light bulb       LED GU10 light bulb
led light bulb colour changing
a little fun with LEDs
a 5w LED downlight that you can dim, flash, fade and change colour from its own remote control