Does turning down the furnace at night actually pay off?
Energy conservation is not only good for the planet, it’s also good for your pocket.
For instance, “is it more energy-efficient to maintain your thermostat setting at a constant temperature 24/7 during the winter at, say, 20 degrees, or to lower it at night to 18 degrees when you go to bed, but then have to heat up the house each morning back to 20?” a puzzled reader asks the Globe and Mail’s popular “Collected Wisdom” column.
The answer is a definite yes, of course: Heating the house in the morning from 18 to 20 degrees takes the same amount of energy as was saved the previous evening by not having the furnace operating while the temperature slowly dropped. In other words, heating the house upon waking is a free ride.
There’s seems to be some debate as whether most people actually do this, maintains Cecil Adams, the mystery man behind the The Straight Dope, a popular Chicago-based question-and-answer columns.
It’s not that they don’t buy the argument, it’s that they can’t figure out how to program their thermostats accurately, he maintains.
Too many adhere to what’s known as "valve theory," namely the belief that the thermostat functions like a gas pedal: the higher you set it, the hotter your furnace runs.
In reality, he explains, most furnaces pump out heat at the same rate regardless of the setting; they just cycle on and off as needed to keep the house at whatever temperature the thermostat dictates.
A study of two identical Canadian test houses showed an 11-degree setback overnight and during work hours generated a 13 percent savings in gas and a 2 percent savings in electricity since the furnace blower ran less.
Does that reflect your experience during our cold winters? Have you done better or worse?
By Gordon Powers, MSN Money
Posted by: sjrw11 | Feb 24, 2022 9:11:53 AM
This is simple physics. It does take the same energy to bring the house back to 20C as was saved going down to 18 in the evening. Where you save the energy is the time it stays at 18C during the night.
My house uses 158 watts per hour per degree C. So if I lower the thermostat 2 C and it spends 6 hours down at 18C I save 158 x 2 x 6 =1896 watt hours ....per night. 30 nights = 56,880 watt hours per month. At 9.6 cents per KW/HR that is $5.46 a month. I bought the programmable thermostats 10 years ago, and they paid for themselves in 3.5 years. It is also more comfortable sleeping in a cooler room.
I must also say that I put in foam draft stops on all the plugs in the house and used the scrap foam from the pushed out foam for the plugs and put that in baby safety plugs from the dollar store. Same saving, $12 investment for the whole house. Payoff was 2.5 Months!
Have a great day!
Posted by: Josh | Feb 24, 2022 11:47:51 AM
Absolutely it makes a difference. Your house loses heat based on the difference between the inside temperature and the outside temperature. The higher the difference, the more heat lost and your furnace makes up the difference. So having a programable thermostat makes a big difference. An even bigger difference is setting the home time temperature to a low level and dressing warmly. I go into some people's houses and it's like they expect to wear shorts and a tank top even in winter. Sure if you like doubling your heating bill.
I haven't crunched the numbers to see how much I'm saving, but everytime I hear someone else tell me how much their heating bill is I know it's making a differenc.
Also, proper insulation makes a huge difference. A $10 can of expanding foam can do wonders.
Posted by: don | Feb 25, 2022 12:42:18 PM
I have never done it so I dont know if it is true but I had a relative that worked for a gas company. They were told there were savings to be had as long as they did not lower the thermostat anymore than 5 degrees. Anything more takes more fuel than you saved to heat your house back up in the morning.
Posted by: June | Feb 25, 2022 1:28:00 PM
Turning down my thermostat four degrees at night and during the day when I started working full time mattered so much that the oil company called me to check a difference of $300 from our usual oil bill during a period of five winter weeks. I mentioned that perhaps it was the milder weather, but they said it was more than that. I told them of the temp difference during the day and sleeping hours and they said "that would do it.!"
So, I have continued the practice. It also helped with the heat pump and hydro bill.
Posted by: Blue Star | Feb 25, 2022 3:00:32 PM
Remember, turning it back at night 3 maybe 4 degrees should suffice. When the air cools it condensates, and that in itself can cause problems. Additionally, the mass in the house takes time to re-heat to a level that will balance the thermostat setting you desire during the day. Turn it down to much, and it will cost more to reheat than the savings you thought were taking place
Posted by: Sammy | Feb 27, 2022 8:59:31 AM
I told my husband it would be nice to have a few hired hands to help with the work at home and he said- we do - hydro.. We hava a programmable thermostat and turn it for 18 at nite and 21 at 6:00 AM and back to 19 at 9:00 AM We heat with eletricity. I enjoy looking at the TOU charts made available to us in mid-December.
We are trying to make our "hired hand" do only work when needed to save his energy and our money