heat efficiency

[grodenhiATgmailDOTcom]

Well my latest oil bill just came in and was a bit higher than anticipated. This got me to thinking... I have a programmable thermostat and maybe I can take better advantage of this. We're having a debate here at work. What would SAVE more oil?

1.) Have heat turned down real low at night (55-60) and when no one is at home, and have it rise to more comfortable levels around when we get home (64-65).

2.) Have the heat lower a bit, but maintain a more constant temperature so it does have to catch up with a cold house.

We live in RI and the normal temp is around 30 (although not so much lately). The heat would be down from 8-5 during the day and 11-5 at night. The house is fairly well insulated and small (1100 sqft). Some say it's actually more efficient to keep it at a constant temp than allow the house to cool than have to work at catching it back up.

[Bob]

For oil, it depends on a lot of factors, including how long a period the heat is down for, compared to what temperature you're setting it down to

24/7. If you had a heat pump, then it's generally very inefficient to set it back unless you have a thermostat that ramps up the temp.

[Joseph Meehan]

Plan #1 will save the most. However make sure you don't go too low, especially when it is very cold outside as you can freeze pipes. Remember that while the room may b e 55º the temperature under the kitchen sink on an outside wall is likely much colder.

Also remember that wide swings of temperature can damage some fine wood furniture and other items in the home.

I will add that you get decreasing benefits as you set it lower. There are several reasons for this.

With electric heat, you may have a time of day rate difference so it might not be good to use a set back and that is why some people will suggest not setting it back. It also is true that if you are using a heat pump, you need to time those set backs so the home in not heating up your home during the coldest part of the day. For example it would not be a good idea to allow the temperature to drop much during the night, because your heat pump would be far less efficient trying to heat it up in the morning when it is usually coldest outside and heatpumps are least efficient.

What you don't need to worry about is that it will take more heat to re-heat the home than it would have taken to keep it at a given temperature. That is never true, although many people believe it to be true.

[Edwin Pawlowski]

This has been debated for years and the conclusion is that lowering temperature helps.

One factor to consider, heat loss is greater when the temperature difference is greater. So, if the outside is 30, there is greater loss at an inside temperature of 70 than if it was 65. Next is the time that the temperature is at the lower setting. If the temperature drops from 70 to 65 and then goes right back up, there is little or no savings. OTOH, if it drops to 65 for 10 hours and then gets back to 70 in 30 minutes, there was a savings to be realized.

[Bob]

temperature.

[Joseph Meehan]

I was not aware of that, but that should help. It still would not change the problem of morning heating when it is generally the coldest outside. But as you noted it is that backup or emergency direct resistance heat that is the real killer.

[RichK]

Yes, turn it down, the more the better. It may seem radical to some, but I find 50F very comfortable at night. I use a small electric heater to pre-heat the bathroom before the shower, if need be. And a small heating pad to preheat the bed. Think sweaters, warm socks during the time you are home.

Why heat the whole space, when all you need is comfortable temp near your skin :-)

This way the house can be at 50F most of the day, except evening, when

62-65F is about right.

Rich

[trader4]

1. Edwin Pawlowski Feb 2, 11:03 am

"If the temperature drops from 70 to 65 and then goes right back up, there is little or no savings. "

There will always be savings in this case, unless you have some issue with aux heat systems for a heat pump or differences in electric rates at night, etc. But for any gas, oil, electric system in general, you will save any time you set the temp back, though I agree, if it's for a short period, it will be relatively small. The savings occur for two reasons. First, the average temp will be around 67.5 for hopefully several hours, compared to 70. A secondary effect of lesser importance is the furnace will be running constantly to take it back to

70, during which time it will be a little more efficient than if it were starting and stopping.

[hallerb]

Well he is heating with Oil, so heat pumps dont matter to him specifically!

Provided you dont let things freeze the lower the better savings wise.

I used to live alone, when I went out in the AM I would set it at 50, come home after work, if I was going out right away I would still leave it at 50. Tended to shower right after work back then. Turn on shower, shut bathroom door, bathroom would get nice and hot!:) Get shower and leave with house still at 50.

When I got home I would set it at 70 and tough it oiut till it got comfy.

Why pay to heat a space when your not home? I mean you dont want it to freeze, but other than that cold doesnt matter.

insulate your home, caulk all air leaks, have a efficent furnace and good windows, wear warm clothes at home, and close off registers to unused rooms like extra bedrooms.

you can get a heat audit where a company puts a blower on your homes door, then checks for leaks with a smoke stick. this can help more

[Bubba]