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Do We Save Money By Lowering the Thermostat at Night?

Reasons to Lower Your Thermostat

It’s an age-old argument heard between couples snuggled in bed, roommates around the thermostat and
 parents of cold-toed kids curled up by blowing air vents all across the country: “Do we actually save energy and money by lowering our thermostat at night?”Lower your thermostat

The simple answer is ‘yes,’ according to Keith Hill, manager, technical support, at Minnesota Air. “Energy and money are saved when you turn down or set back the thermostat in the winter, whether it’s just a degree or two for a few hours, or ten degrees for half a day.”

The bigger question people should ask is: How much money is saved, and will you notice a difference on your energy bill? To find that out, Keith says we need to look at the temperature differential between the inside and outside of your home.

Know Your Temperature Differential

For example, imagine a ten-degree December night in Minnesota (that’s downright balmy, right?), and suppose you want the thermostat inside your house set at 70 degrees. If so, the differential is 60 degrees.

“Imagine that temperature differential like a ‘heat pressure’ inside trying to escape through porous walls,” says Keith. “The greater the pressure difference, the greater the amount of heat escaping.”

The colder it is outside means the bigger the differential from the inside temperature, and the harder your home will have to work to maintain your ideal temperature. Keith says, with that in mind, setting back your thermostat from 70 degrees to 65 degrees when it’s 60 degrees outside won’t have as much of an effect as when you do the same when its 15 degrees outside. But every little bit helps.

In addition, you need to look at how long you want to have your heat turned down. Obviously, the longer it is set back at a lower heat, the more heat energy will be saved.

“If you set it back only a degree or two for a few hours, you are saving energy, but will you notice it on your fuel bill? Probably not,” says Keith. “If you set it back ten degrees for a ten hour period every work day, then you should notice a change on your energy bill.” 

Sleep Well

That applies for lowering your thermostat at night, too. Not only do cooler temperatures induce sleep, but lowering it when you are tucked snugly under the covers for eight hours can save you money.

Keith does give a word of caution, however, to those wanting to turn their thermostats way down overnight. For an ideal comfort temperature and to keep your furnace in-check, keep it above 60 degrees.

He says most modern furnaces have a minimum return air temperature of 60 degrees and damage will occur to the furnace if it is operated with an indoor air temperature below that. “It causes moisture to form in the heat exchanger and may lead to premature heat exchanger failure. It can cause corrosion issues with other components as well,” Keith explains.   

Some argue that it may cost more to heat your home back up in the morning. According to the Department of Energy though, maintaining a consistent higher temperature uses much more energy than maintaining a lower one and heating it back up to your ideal range. Saving money can be as easy as setting your programmable thermostat to a comfortable temperature by the time you get out of bed.


For more energy saving and home comfort tips, visit! Stay Comfy, Minnesota is your Minnesota resource for air conditioning repair, furnace repair and HVAC tips and advice. System Giveaway

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