is it more efficient to turn off your heat or to turn it down when going to sleep/leaving your home for long periods of time?
In: Technology
Depends on how long you are going to leave it off.
If you shut it off just long enough to get it as cold as it will go, then turn it back on, it will use more energy to heat it back up again vs. having left it on and let it stay warm. If it will get cold and leave it cold, then you will be saving energy.
But also, there are reasons you should not let your house get too cold. So it may do harm to other things if it gets too cold in your house.
Plants could die, pets could suffer. And if it gets below freezing, all sorts of bad stuff can happen in your house.
Turn it off.
Same misconception about letting your car idle vs. shutting it off, that it would use more fuel to crank then to idle for a short duration. Any furnace will use much less fuel to heat the house back up than it would use to keep the house continually warm throughout your absence. Think about it. The heat goes _somewhere_ and the warmer the house, the more heat there is to escape it. Outside. So keeping the furnace on just pumps heat outside. So turn it off.
Caveat: we’re assuming here that you’re not going away long enough to let the house temperature drop below freezing – frozen pipes = $$expensive. But setting the thermostat so that no place in your house gets below maybe a few degrees above should be fine.
Yes.
Heat loss is a function of the temperature difference between inside and outside. If you allow that difference to be lower, you will lose heat at a slower rate.
Gas? Turn off
Electric? Lower temp
Heater is usually an on/off switch controlled by a thermostat.
Basically it runs this computer code in a loop:
“`
IF current_temp < set_point
THEN turn_heater_on()
ELSE turn_heater_off()
“`
Say you keep your thermostat at 70 when you’re awake, and 60 when you’re asleep.
If it takes your house 15 hours to cool down from 70 degrees (F) to 60 degrees, there’s no difference between turning down to 60 vs turning it off when you sleep (assuming you’re a normal human who sleeps for less than 15 hours a night).
Think of it this way: Option 1, turn it off. Option 2, tell the computer to turn it off as long as it’s above 60 degrees, but it never actually gets below 60 degrees.
There’s a big benefit to turning it down instead. If you’re in an area where it gets below freezing in the wintertime, setting the heater to a low value keeps pipes from freezing, if you’re unexpectedly away longer than planned.
How long it takes your house to cool down depends on a lot of factors: Outside temperature, size of your house, insulation, windows, opening / closing of doors.
Nowadays you can get a thermostat that you can set to change temperature based on time of day, or even lets you control remotely from your smartphone (so for example if you’re running errands and don’t know when you’ll be back, when you’re done with your errands and ready to head home, you could use your phone to tell it to turn up the heat.)
It’s always more *efficient* (or at least *as efficient*) to turn it off, but that’s not the primary concern when it comes to one’s home.
Overnight, there’s a minimum temperature below which the occupants will get uncomfortable. Set the thermostat to that level. If the home passively retains enough heat overnight to remain above that level, your energy savings will be identical to turning the heat off entirely.
There’s also a minimum temperature below which damage can occur to plumbing and appliances. When leaving the home for a day or longer, set the thermostat to that level to avoid expensive repairs. Again, if the home passively retains enough heat while you’re away to remain above that level, your energy savings will be identical to turning the heat off entirely.
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