Hot upstairs, freezing cold downstairs

[many a good man]

What can I do to make the upstairs stay cool? Its so much hotter all the time upstairs, which is to be expected since hot air rises, but it kills my checkbook when its too hot to sleep.

I don't have a roof fan, but the attic is insulated and the soffit vents are standard. Will I gain any relief by putting in a roof fan?

What about a fan built into the ceiling of the second story? Its a two-story townhouse so it would vent to the attic in the summer. I heard some fans can be reversed and blow down in the winter. Any opinions on this one?

Any other tips?

[Warpy]

1. Just a window fan exhausting out during the afternoon

will pull some of that cooler air upstairs while it pushes that hot air out the window. Most window fans can be reversed at night to pull the cool night air into the room.

That's the cheap and dirty solution.

[wildeyed]

2. I close the shades during the day,

we have the honeycomb type that also insulate the windows, and run the ceiling fans all day in the upstairs rooms. We are in NC, so we still run the central AC, but not at full blast.

The people who owned the house before us had window AC units in two of the upstairs rooms, in addition to the central AC. I guess they could equalize the temperature in the upstairs and downstairs spaces more easily that way.

[eleny]

3. A wind turbine vent might help a lot

Perhaps replace one of your standard vents with one like this.

[Stinky The Clown]

4. A few things .......

You don't say where you are or if you have central AC.

If you have central AC, and exhaust fan in the conditioned space just sucks out the air you paid dearly to cool. It would be far, far better to exhaust the attic space above the insulation. Reduce the attic temp and it will allow the second floor to be cooler. I'd strongly advise a thermostatically controlled power exhaust fan. A cheaper but somewhat less expensive alternative is the turbine vent eleny mentioned. They're considerable more effective than a plain old louver vent, but not nearly as effective as a powered exhaust.

If you *don't* have central AC then a whole house fan set into the second floor ceiling is very effective. Crack open the lower level windows on the north side (where outside temps are coolest) and allow that to get drawn through the house to the exhaust fan. After the sun goes down, you might even be able to open the upstairs windows if the outside temp is comfortable ..... and if no one has 'nightime' allergies.

[Stinky The Clown]

5. It helps if one reads what one types ......

The line that reads "A cheaper but somewhat less expensive alternative ..... " shoud *actually* read "A cheaper but somewhat less **effective** alternative ..... "

[Warpy]

7. "Freezing downstairs" was part of the problem

and the ideal solution would be to have a fan between floors to circulate that cold air upward during the summer and the stratified heated air downward in winter.

If it's forced air AC, then check those upstairs vents. Either they're closed or the unit simply isn't cycling often enough to keep the air from stratifying. Adjusting the fan in a forced air system to remain on between cycles may be your solution.

Still, the cheapest way out there is to switch on an exhaust fan out the window when you go upstairs, blow that hot air out the window and suck some of that cool air up from the freezing living room.

The soft fan will help, also, by keeping the attic space from overheating, but won't do much to warm up the over chilled lower level.

[FloridaPat]

6. Radiant barrier in the attic would send a lot of the heat rays out to

space.

[many a good man]

8. Thanks for the great advice

I have a west-facing brick townhouse in the DC suburbs with central air. Therefore I guess a "whole house attic fan between the second floor and attic" wouldn't be wise. Maybe it would be helpful between seasons when neither heat nor A/C is blowing.

The power exhaust fan on the roof sounds like it might be the most effective-- it does get horribly hot up there the few times I've ventured.

The radiant barrier thing sounds good. Hopefully its affordable for a small townhouse. I'm a little worried, though, that it may reduce some of the free solar heating I get in winter time.

Stratified air...hmmm. I think the main problem is the big temperature differential. The vents seem OK, but its always much warmer upstairs so my wife cranks the A/C at bedtime (and siesta time) causing it to be too cool for comfort downstairs. I don't know where I would put a fan between the upstairs and ground floor. I used to put a big piece of cardboard at the top of the steps to keep the cool air from sinking downstairs-- it seemed to work a little. I have a big tilting fan I could put there, but should it tilt up or down?

How can I adjust the A/C so the fan goes on even when the thermostat thinks it doesn't need cooling? The temperature outside goes down at night so the cooling doesn't kick in very often, resulting in stagnant air and uncomfortable temps. I'm OK with it but the wife feels the heat more than I do. A small fan usually helps but seems redundant.

Thanks again, everyone!

[Stinky The Clown]

9. Your thermostat should have an on-off-auto switch for the fan.

Set it to 'on' and it should run constantly. Set it to 'auto' and it only runs when the furnace or AC are running. We leave ours on 'on' year round.

If that doesn't give some relief, then use that tilting fan to move the more desirable air from where it is to where you want it (blow up in summer to get the cool air up, and blow down to get hot air down in winter).

[DancingBear]

10. What is the temp difference?

If you have single zone A/C, and if your house is around 20 years old, then you're part of a very common problem.

I live in northern VA, and the temp difference between up/down in our home was about 10 degrees - 4 or 5 degrees is normal for a single zone system.

This is how we fixed it (and you're not gonna like it) - we replaced the old furnace (2.5 ton) with a 4-ton unit, and increased the size of the ductwork.

By closing off the downstairs registers, we can get the temp difference back to about 4 degrees.

If you have this type of single zone system, then a roof/attic/whole house fan will not help much. I speak from experience. :)

Oh, almost forgot the obvious - have you cleaned the furnace filter recently? If dirty, that will make a HUGE difference in how much air the A/C unit can pull.