HVAC in the attic?

hbaird · Aug 11, 2005

An advantage in keeping the air handler and even the duct work in the heated and cooled area is efficiency. The heat transfer in the attic can be substantial. I saved 12000 BTU's, one ton, on my system by keeping everything out of the attic. Attic temps can run over 140 degrees F in even a well ventilated attic. The air handler will be under 50 degrees F(no lose). And the air inside the handler and ducts is moving very fast and turbulent causing optimum heat transfer. A major home builder in Dallas TX designs their homes around a hallway based ductwork. The hallway ceiling is dropped about a foot to hide the duct.
Harold

Jagmandave · Aug 11, 2005

I think the trend came from homes built on slabs, where it was difficult or impossible to run the ducts anywhere but in the attic. At first it seems to make sense to put it there, but as hbaird says, that's a lot of heat gain to overcome in the summer..........

KubotaSteve · Aug 11, 2005

My brother puts in HVAC systems in new houses in the ritzy part of Virginia. The set-up for the upper floors is always in the attic and they have very few problems. Like someone else said, they have a cut off switch if the drain line backs up into the pan.

BB_TX · Aug 11, 2005

I think the trend came from homes built on slabs, 
Not exactly true, at least around here. Most all houses have been built on slabs here for many years. But most AC fans/evaporator units were upflow units put in closets, typically in a hallway, with the duct work in the attic. But newer houses seem to have the fans/evaporator horizontal flow units put in the attic. I guess to save a closet and a small amount of floor space. Or maybe it is just cheaper. My MIL's house and a duplex my wife and I lived in years ago, both built in early '60s, were both pier and beam and they both had them in a closet with the duct work in the attic.

Bird · Aug 11, 2005

Guys, I surely appreciate all of you. I've owned 3 homes in the past; all on concrete slab foundations in the Dallas area. The first "old" house had window unit air-conditioners while the other two, bought new in '72 and '77, had the indoor components in a closet and the blowers of course blew the air up into ductwork in the attic. The little house we're considering has the compressor/condenser unit on a concrete slab beside the house and the evaporater/air handler (or whatever) in the attic. The realtor tells me that's what most of the homes in the area have since the '80s (the house we're considering was built in '91). I guess I'm just a little out of date, having lived in RVs or mobile homes the last 16 years. And I do, a couple of times a year, pour bleach into the PVC condensation drain on our current air-conditioner. I'd never thought about using a shop vac to suck out the line, although I have, on occasion, used the air-compressor to blow out the lines. When we looked at the house we're interested in, it was just a cursory visual inspection, and of course, before we buy (if we buy) I'll do a much more thorough inspection. The day we were there, a pickup truck in the garage was blocking the access to the attic, so I haven't even looked up there yet.

Many thanks to all of you!

slowrev · Aug 11, 2005

When in FL, My home had the HVAC air handler in the attic. Drain clogged and pan ran over messing up a lot of ceiling. It had a float cutoff switch in the pan, but it was not hooked up /forums/images/graemlins/frown.gif

Left FL about 4 yrs ago and when I left I believe they were stopping putting the air handlers in the attic for some kind of hurricane reason. Not sure on that though.

Ben

Bird · Aug 11, 2005

Ben, that's what happened to the only guy I ever talked to who had that kind of unit. But he said that after that damage was repaired he poured bleach through the drain line every month. /forums/images/graemlins/tongue.gif

NewToy · Aug 11, 2005

We just built a new home in SE Ohio and installed a geo-thermal unit where everything even the condensing unit is in the basement. It is a bit costly initially but our electric bills have been under $100 since last August. This thing generates hot water when it's running so the water heater doesn't hardly ever come on. The house is 2100 squares and is all electric. They are really worth looking in to.
Also, we had the attic arrangement in FLA and the bleach trick kept things moving. Once I had a clog and was able to hook my shop vac to the drain line outside and sucked the whole glob of junk out.

John

Bird · Aug 11, 2005

( electric bills have been under $100 )

Of course we won't have a basement, but that sure sounds good. My last electric bill in this little mobile home was $194.