Running Air Conditioner at night

[Pondhockey]

We have a little used house in Idaho, where the Summer heat fluctuates 30-40 deg from early morning to late afternoon. The house is recently built with good insulation and double pain windows, we leave the blinds closed.

We wish to maintain a reasonable temperature while we try to sell the house. My proposal is to run the A/C in early morning to cool the house to 60 deg F, then set the day time max at 80.

Can you comment on whether this is a reasonable strategy? (Since we aren't there, we can't "open the windows", etc.)

Thanks.

[jtrammel]

Why not just set it to 75-78 and leave it alone? Cooling any house to below 70* is not recommended in the summer. It can cause moisture problems.

[HVAC_Marc]

set it at one reasonable temp like 75 and leave it there. otherwise it's just wasting energy

[kdean1]

That is a lousy strategy. It will not save energy. Just set the thermostat to a higher temperature to conserve energy.

[ammoniadog]

60 degrees in the morning and 80 in the afternoon? I don't see any logic in that strategy what so ever.

If you're trying to sell the house, wouldn't it make more sense to make it comfortable for people during the hours that they might come over to see it? Otherwise you might as well just winterize the house, board up the windows, and shut off all of the utilities.

You're not going to save anything by trying to over-cool the house in the morning, unless you have a substantially cheaper off-hours electricity rate. Even then, there probably wouldn't be much point.

You might be able to save a small amount of power if you set the thermostat a little higher during un-occupied times, but once again I don't see much point if it is only going to be for a hopefully short amount of time until the house sells.

I would recommend following JT's and Hvac_Marc's advice.

[BaldLoonie]

You'll freeze it up!

[Pondhockey]

60 degrees in the morning and 80 in the afternoon? I don't see any logic in that strategy what so ever.

If you're trying to sell the house, wouldn't it make more sense to make it comfortable for people during the hours that they might come over to see it? Otherwise you might as well just winterize the house, board up the windows, and shut off all of the utilities.

You're not going to save anything by trying to over-cool the house in the morning, unless you have a substantially cheaper off-hours electricity rate. Even then, there probably wouldn't be much point.

You might be able to save a small amount of power if you set the thermostat a little higher during un-occupied times, but once again I don't see much point if it is only going to be for a hopefully short amount of time until the house sells.

I would recommend following JT's and Hvac_Marc's advice.

OK, I thought the details were apparent, sorry.

If I cool to 60 in the early morning, then since the outside temperature is also near 60, it should be considerably easier (less energy, less cost) to cool. Since most visitors will show up between 9 and 5, the temperature that they experience will presumably be between 65 and 75, topping out at (say) 80 on an especially warm day, or later in the evening.

(The housing market is recovering and not so hot that I can assume it's a short time.)

Everyone so far thinks it's best to leave it at a set temperature; maybe that's right, although no one has satisfactorily explained why.

Thanks for the response.

[jtrammel]

Everyone so far thinks it's best to leave it at a set temperature; maybe that's right, although no one has satisfactorily explained why.

Thanks for the response.

Cooling any house to below 70* is not recommended in the summer. It can cause moisture problems.

As in mold inside the walls on the back of the Sheetrock, ductwork sweating inside walls etc. anything below 70 is asking for trouble.

[HVAC_Marc]

although no one has satisfactorily explained why.

it's just wasting energy

.

[Pondhockey]

As in mold inside the walls on the back of the Sheetrock, ductwork sweating inside walls etc. anything below 70 is asking for trouble.

OK, that's fair, Thank you. I just checked the historical average dew points and for June, July, August they are 54, 60, 60, so my proposal is pushing it.

[Pondhockey]

.

Yes, Marc, I did hear you, but I don't understand why/how it is wasting energy, when I think it might be saving energy. I do appreciate the vote.

[jtrammel]

Also, as baldloonie pointed out, you can cause the evaporator to freeze up if ran below 70* and with low outdoor temps. This causes strain on the compressor, fan motor and the coil itself. It causes liquid refrigerant to come into the compressor and can completely ruin it. Also a frozen coil can cause water/condensate problems.

[Pondhockey]

OK. Thanks to all.

I'll set it at 78 and leave it there.