So the ramp up/down energy usage is less than, say, 8 hours of maintaining temp then?
Generally yes. There might be exceptions with A/C units which are less efficient when under full load, but they're usually inefficient anyway and the savings not having them running are higher.
Thank you. It's a question I've had for years and no one ever really had an answer.
Does it actually save you money or does it cost more to ramp it up from being off for a while.
I think it saves. It doesn't seem like it takes long for it to heat back up. *(as in the furnace doesn't run long)
I'm sure the size of the house and the quality of your windows and insulation are important variables.
In my case, during the hottest part of summer where my AC stays on constantly during the day, it saves me a bit of money to turn it off and crack a few upstairs windows if I wont be back until after dark. In the winter I just leave the heat on since nightfall doesn't help correct the temp.
As for ramp-up power usage, I'm not sure about heating systems, but I'm pretty sure AC systems are operating at 100% power usage any time they're on.
If you're really looking to cut some costs during the winter, invest a little time in making sure your place is well insulated. I'm pretty sure you can rent a thermal camera to track down hot/cool spots. If you're feeling really hardcore, you might also consider just turning your heating system way down and using a space heater in the rooms you use most.
Got my Amana portable air conditioner in mid-July, just barely ahead of the anticipated heatwave (Dog Days has always been mid-July through late September here). Then no heatwave! First time in 20 years. When the outside temperature is hotter than the inside (say 90 degrees inside & 95 outside) then cracking windows does no good, and a window fan just turns into a heater, so those days is why I dropped near $400 on an air conditioner. Still a bit POed that I never got to test it, but oh well, it's here for next year.
I rent, so not much I can do about insulation. Landlord made a huge mess for me to clean up two years ago, by ripping out my windows, and sticking in giant double-pane insulated ones. Not keen on a repeat performance (ceiling to floor scrubbing), so I'll not be putting any ideas in his head. Utilities is included in the rent, so not my problem anyway. I been here maybe twenty years now, and never used the installed wall heater. I like cold nights sleeping under covers, and within a few hours after dawn the place starts to heat up....without the window fan going year round it would feel like a foundry in here.
If it ain't in use, there's no reason to use it. I shut down everything except window and bedroom fans. Never used the heater (in NorCal its useless). Portable air conditioner is only for days when the outside temperature is higher than the inside, which makes a window fan useless. When I leave a room, the light gets turned off. When I'm finished with the PC, I shut it down via the software, then cut its power. Leaving stuff on to waste electricity is like leaving the faucet running to waste water, or wasting food by being too lazy to stick it in the fridge.....it's always cheaper not to.
"According to the U.S. Department of Energy, a family that sets back its thermostat by about 10 to 15 degrees for eight hours a day while sleeping or out of the house can save 5 to 15 percent a year on home heating costs."
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