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Energy myths and facts

There is plenty of information out there on the best way to save energy but there are also plenty of myths floating around! Here are some useful facts for you to consider....

1. Switching lights on and off uses more energy than leaving them on if I’m only going to be out of the room for a short while.

FALSE: This used to be true years ago for fluorescent tube lights which took some time to start up, but now the rule is that the longer the light is on, the more energy it uses. The energy used to switch a light on and off is less than that of leaving it on, so switching lights off when you leave the room saves energy, whatever type of bulb you have.

2. Leaving the heating on overnight uses less energy than re-heating a cold building.

FALSE: A boiler that spends an hour heating up a room in the morning is working no harder than a boiler that spends 14 hours switched on overnight. The only difference is that one is switched on for an hour, and the other for 14! 

3. Repeatedly turning computers and lights on and off reduces their lifespan, and wastes energy required to produce new ones.

FALSE: Leaving computers on when not in use actually reduces their lifespan, because moving parts wear out faster.  Lights are designed to be switched on and off many times a day without affecting ther lifespan.

4. Energy saving light bulbs can’t be used with dimmer switches.

FALSE: There’s now many energy saving light bulb options, including ones that can be dimmed, and ones with different hues of light. 

5. Computer monitors use less energy when the screen saver is on.

FALSE: LCD screens use exactly the same amount of energy, whatever colour they are displaying, so the screensaver uses just as much energy as when you are working. The best thing to do if you are leaving your desk e.g. for a meeting is to switch off your computer screen.

Did you know?

  • A 2°C increase in office temperature creates enough CO2 in a year to fill a hot air balloon.
  • Lighting an office overnight wastes enough energy to heat water for 1000 cups of tea.
  • A photocopier left on overnight uses enough energy to produce over 1500 copies.
  • A typical window left open overnight in winter will waste enough energy to drive a small car over 35 miles.
  • A PC monitor switched off overnight saves enough energy to microwave six dinners.

SOURCE: Carbon Trust

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