Why does lowering your home thermostat at night save fuel? Isn't a degree a degree no matter the temperature?

It seems to me that decreasing the thermostat during the night while you are asleep will simply save a bit of fuel while your home decreases its ambient temp down to the new setting. Let's say you go from 68 degrees to 62 degrees. Let's say it takes an hour to decrease those six degrees; you've saved an hour of furnace time, but then for the rest of the time the thermostat will behave normally by maintaining the temp at 62, which should be no more nor no less efficient than maintaining it 68, right?

Then, in the morning, the furnace has to work overtime to get the home back up to 68, thus mitigating the savings on the down side. What am I missing from this equation? Why does the DOE claim a 10% energy savings by lowering the thermostat at night?

Asked by jonschn 49 months ago Similar questions: lowering home thermostat night save fuel degree matter temperature Environment > Energy.

Similar questions: lowering home thermostat night save fuel degree matter temperature.

You lose less heat when your temperature is closer to ambient The lower the temperature, the less heat loss. In your example, if it is 62 degrees outside, your furnace will stay off all night.

In any situation that you are maintaining a temperature differential... The greater the temperature differential, the more energy it takes to maintain that differential. If it is 50 degrees outside, and you are maintaining 68 degrees inside, it will take less energy than if it is 40 degrees outside and you are maintaining 68 degrees inside. That is why the heating bill is more in the winter.

Similarly, it takes less energy to maintain 62 degrees inside than it takes to maintain 68 degrees inside. So the answer would be "...maintaining the temp at 62, which should be no more nor no less than maintaining it 68, right? " is wrong.It is more efficient to maintain it at 62.

That is where your energy savings comes into effect. The magic number of 5-10 degrees was arrived at as a guide to how much your house will cool during the "reduced heating" time, without just making it that your heating system only runs when you’re home which ISN’T more efficient.So you do a reduced temperature period for 6 hours. It takes 1 energy unit to raise the temperature 1 degree.

Your house loses 10% of its temperature differential per hour. Your warm setting has a temperature differential of 20. Your cool setting has a temperature differential of 15.

In the first hour, the temperature differential drops 2, and there is no heat applied.In the second hour the temperature differential drops 1.8, to 16.2, and there is no heat applied. In the third hour, the temperature drops 1.62 to 14.58, and the furnace uses .42 EU to recover to 15. In the fourth hour, the temperature drops 1.5 to 13.5, and the furnace uses 1.5 EU to recover.In the fifth hour, the temperature drops 1.5 to 13.5 and the furnace uses 1.5 EU to recover.

In the 6th hour, the temperature drops 1.5, and the furnace uses 6.5 EU to return to the 20 degree warm setting. Total energy: 9.92 EU by comparison, each hour at high temperature, the differential drops 2, and the furnace uses 2EU to recover, with a total 6 hour expenditure of 12 EU Clear as mud?.

The furnace runs less total time. The closer the temp inside is to the outside temp, the less your heater needs to run. Wouldn’t you agree that it would cost more to maintain a home at 90 than 70?

The warmer the house is, the more the furnace has to work to maintain that temp. And the less insulation you have in your home, the faster that temp drops too. If you took an infrared picture of your home with an internal temp of 90, you’d see it giving off or losing heat faster than if it was 70.My furnace runs about 15 minutes in the morning to go from 62 to 70.

Now, if I kept the thermostat at 70 all night, it would certainly run for a total of more than 15 minutes during the course of the night.

Well,because it takes less time to raise the temp baxck up than it does to lower the temp. You should also lower the temperature in your home if you're gone more than an hour or two. My thermostat is at 60 at night and during the day when I'm gone, and set to 67 when I am waking up in the morning and when I come home at night.

I save about $40 a month during the cooler months. The difference between the ambient outside temp and the inside temp makes a difference to how much you're going to save. Schelli's Recommendations Automatic and programmable thermostats (SuDoc E 1.99/13:215) The energy conservation potential of winter thermostat reductions and night setback (ORNL-NSF-EP-80) Saving energy the easy way: An analysis of thermostat management Home energy management devices: Concept testing of an electrical peak demand controller for residential loads : power consumption cost indicator : a study ... conserving microcomputer-based thermostat The importance of room thermostats in energy conservation The effects of thermostat setback and setup on seasonal energy consumption, surface temperatures, and recovery times at the CCHT twin house research facility.

: An article from: ASHRAE Transactions Amazon List Price: $9.95 .

Because if it is 50 degrees outside, it takes less energy to keep the inside at 62 than it does to keep it at 68. It takes energy to maintain temp. The lower the temp you try to maintain, the less energy you use..

How much electricity do you save when lowering the winter house temperature by 5 degrees.

Why did my home water temperature suddenly increase when I didn't adjust the thermostat on the water heater.

I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.