A/C question: Help me solve the “It’s too hot in the upstairs level” dilemma. (new house, buy)

[FCNova]

I have the same issue in my 3 level townhouse. I know I will always have temperature variances between the levels because the HVAC is in the basement, but I also know the problem is exasperated because the structure is leaky as hell and under insulated. If your house is old and has never been sealed up it's probably leaky. Even some new houses probably have issues. What you need to do is have the house(attic in particular) sealed up really well, and then make sure your insulation is adequate. I've read good things about radiant barriers too but can't vouch for it yet as my project isn't done. It's going to be very costly to have done or you can DIY at a fraction of the cost but it'll be very time consuming. Here are some links to what I'm talking about

http://www.energystar.gov/ia/partner...e_May_2008.pdf

http://www.dmme.virginia.gov/de/cons...AirLeakage.pdf

[finecognac]

Originally Posted by coolio69

Finecognac,
When you say 'cap off the top floor,' do you mean sealing off the entire top level with a door? We have an open staircase that goes up and is open so that would mean a serious remod.

No, I meant cut off the duct works going up to the upper level and also cut off the return from upper level. It's very easily done in the mechanical room in the basement. We had the same problem before and once we added the second unit in the attic, our heat problem in the summer/cold problem in the winter disappeared. The heating and cooling cost remains pretty much the same since the heat pump no longer working extra hours.

[Carlingtonian]

We have an old house with central air, and our upstairs BR is also hot in the summer. For now we just use a standing electric fan pointed toward the bed, and that helps a lot. Many of our neighbors augment their central AC with a window unit, so we'll probably do that too at some point.

[ecko_complex24]

You can get a thermostat with a remote censor and put it upstairs that way the unit won't satisfy until the upstairs reaches the desired temperature. I have installed these at banks where the temperature didn't balance out because of computers ATM machines etc.

[South Jersey Styx]

If you are considering two zones in your house, you might want to explore a ductless AC system for the upstairs floor:
Ductless Split Systems | Friedrich Air Conditioning

This is only one company but you can research other manufacturers.

[sullyguy]

> ...augment their central AC with a window unit...

That particular solution is not allowed in Sully Station - against HOA.

[ChristineVA]

Best thing you can do for yourself, as another poster suggested, is dual-zone HVAC. Getting a larger unit isn't going to work. Most homes at 2400 sq. ft. and above should be dual zone. I'd argue for even lesser square footage.

The two places I lived before my current home had all the same problems you mentioned. There was really no fixing it and, I swear, we tried it all. My current home, which is 17 years old and has dual zone. It's wonderful.

[Pandoras]

Originally Posted by coolio69

I have the original A/c central air unit in my SFH. In the cooler spring, the upstairs level is nice and pleasant, but in the summer months, it struggles to keep the temperature comfortable (about 75 degrees or thereabouts). This is especially uncomfortable at nights (our BR is up there).

I think my unit may be on its last legs so I’m beginning to think of options. I used to live in a townhome where I had the same problem, which was also not solved. Back then, I was recommended a 1.5 ton unit, I think. I wanted to go for a 2 ton unit, but the installer recommended against it. Their reason was the square footage of our place. I went with the smaller tonnage unit to my dismay.

Would going for a higher tonnage unit solve my upstairs cooling problem now? I’ve also heard good things about attic fans. And, I’ve seen an attic fan at Costco recently. BTW, I have only 3 levels in my house. Any suggestions, tips? Or is this just a fact of life in upper levels around here?

I think dual zone ac is best if you have 3 or more floors. Have you looked at getting solar film for your windows or a ceiling fan? And have you looked at getting a portable AC unit? You do have to vent them but they look quite unobtrusive compared to a typical window unit.

[car54]

As mentioned, multiple zones is the way to go.

The AC guy is right about upping the size...too big is as bad as too small in AC. It would seem like the bigger the unit the colder it would get, but if the unit is too big it doesn't run long enough to dehumidify properly. In AC, dehumidification is at least half the battle...

[finecognac]

Originally Posted by ecko_complex24

You can get a thermostat with a remote censor and put it upstairs that way the unit won't satisfy until the upstairs reaches the desired temperature. I have installed these at banks where the temperature didn't balance out because of computers ATM machines etc.

ecko but then the main floor will be freezing cold.