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| Green Building Bible, Fourth Edition |
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These two books are the perfect starting place to help you get to grips with one of the most vitally important aspects of our society - our homes and living environment. PLEASE NOTE: A download link for Volume 1 will be sent to you by email and Volume 2 will be sent to you by post as a book. |
Vanilla 1.0.3 is a product of Lussumo. More Information: Documentation, Community Support.
Posted By: tonyDoes switching off lights in a heated building save energy?It depends what is providing the heat. In my heated building, the lights all have a COP of about 1 (we have very few CFLs). If I turn them off, the heat has to be made up by the heating system, which, in my case, has an annual average COP of around 2.7. So yes, switching off the lights does save energy during the heating season.
Posted By: jms452So even in Paul’s heat pump doesn't 'save energy' per se. It does use less electrical energy than direct electrical heating but the 'saved' energy is pumped in from somewhere else.It does save paying for the energy or emitting CO2 though - the energy that's pumped in has come directly from the sun.
Posted By: jms452I might have missed something but I think that that's about rightOnly a tiny proportion of the energy that goes into a running a lightbulb ends up as light (if it's incadenscent) - a larger percentage for CFLs and LEDS but all the other energy that goes in comes back out as heat - which is useful, though may be a source of CO2 emissions depending what was used to generate the electricity in the first place.
Posted By: jms452So the question might need to be more specific (unless you want an interesting but increasingly diverging and academic debate).Of course the question needs to be more specific - but it just goes to show that there is almost never a simple "correct" answer. It all depends. In my case, as I demonstrated, switching off the lights during the heating season saves energy (and energy = $$ in these discussions). But for my neighbour, who heats with oil, it will increase his CO2 emissions if the lights are out since the heat has to be made up from his heating system (assuming the thermostat is at the same setting in both cases).
Posted By: evanFrom the EST newsletter I just received:
"If all 26 million UK homes swapped one string of standard fairy lights for LED lights, during the 12 days of Christmas alone -financially, it would save nearly £8.5m. That’s enough to pay the weekly energy bills for 370,000 homes!"
Hmm.
Posted By: djhDoes anybody know where you can "swap one string of standard fairy lights for LED lights" at zero cost?
Hmm, indeed. Apparently the EST need to hire some accountants, or just resist the urge to make statements like that.
Posted By: SteamyTeaThe reason I mention this is that most of the 'heat', which is energy, will most of the time be at ceiling level where it will do little good.It will do just as well there as anywhere else as it's converted to IR and will thus radiate everywhere in the room.
Posted By: SteamyTeaThe comment about resistive heating is interesting, in itself it is a very efficient method of heating as it is extremely controllable and saleable.More than 70% of people in Quebec heat via straight resistance heating ... though there are attempts to get them to migrate to heatpumps for obvious reasons (which, despite our harsh climate, still work well even with temperatures as low as -12C or worse).
Posted By: DamonHDResistive heating generates *only* 1kWh of heat from 1kWh of electricity (and thus typically 500g of CO2 emissions in the UK for grid electricity).
Using a heat pump would take maybe 1/3rd kWh of electricity to generate that 1kWh of heat, so 1/3rd the money and 1/3rd the emissions eg ~170g.
Burning natural gas to get 1kWh of heat in a modern efficient boiler for example will cost 1/4 of the electric resistive heating and produce 190g of CO2 emissions.
