Furnace / AC Fan Coil in Attic?

[Pete D]

Hey folks

I live in the suburbs of Cleveland OH in a single-story, L-shaped ranch with hot water baseboard heating. As such, with no ductwork for forced-air ventilation, I have no central air conditioning.

Because my attic allows easy access to the ceiling of virtually every room in the house, I've been soliciting estimates for the installation of a central AC system, which would basically be a compressor unit outside plumbed to a fan coil (air handler) unit in the attic with an insulated plenum that would feed insulated flex ducts to each room of the house. Most of the contractors have spec'd one large single 'return' in the main hallway, versus returns in each room, tho some have spec'd that as well.

Anyway, that's all well and good, and the estimates are at least cosistent, coming in around $7-9K. However one of the contractors today threw out an option that I hadn't considered...he asked if I wanted a furnace up in the attic as well. The added cost would only be about $700 (I already have gas lines up there).

This is REALLY attractive to me, since I have little use for hot water baseboard heating (I know some folks LOVE it, but I'm sick of the maintenance, and just don't like the heat...takes too long to warm things up)

Is there any down-side to putting a furnace in the attic? Will operating in the sub-freezing ambient attic temps for the majority of the heating cause the unit any extra wear and tear, or cost me more to heat?

And for that matter, does the AC plan sound reasonable?

Any thoughts at all would certainly be appreciated.

Pete D Willoughby Hills OH

[deke]

I've had horizontal heat/cool gas unit in attic for 23 years and like it just fine. There is no downside.

I'd recommend double insulating the duct work and by that I mean add some extra insulation on the outside of the ducts.

I'd also recommend a variable speed air handler. They save you some bucks.

And of course a hi efficiency furnace 95% or so.

You'll love it.

[DB]

I wouldn't worry about it. We have one like you describe in a townhouse. It works fine. It also beats having to go into a crawlspace under the house to work on an air handler or duct work like in the house I actually live in. About the only better option, maintenance wise, I can think of is a dedicated room to put it in, the furnace anyway, and most houses don't have the space. Also keep in mind the system will be insulated and installation of equipment in un air conditioned space is the norm. It's designed to operate under those conditions. One thing you might want to consider is where they run the refrigerant line. It can make some noise like running water if you are in close proximity to it. It isn't very loud but you might not want it running up the wall behind your bed.

[Pete D]

Thanks Deke !

That's exactly the kind of unit he was recommending, and exactly what I was hoping to hear...

PD

[Steve Barker]

That's exactly what I have in my house. Keep in mind (contrary to other replies) you should NOT put a 92+%'r in the unconditioned area. Any HVAC man who knows what he's doing will not put one there. Mine's an 80%'r and works just great. The furnace could care less where it is other than the above restriction.

[Steve Barker]

If the guy is good, he can use wall cavities as returns and get the returns near the floor. For summer, it won't matter.

[Don Young]

True in a gravity flow only system but a fan can blow heated air in any direction. A properly designed forced air system will maintain a pretty uniform temperature throughout the home. Because of seasonal variations it is difficult to maintain uniformity in multi-story and similar type homes unless the system is zoned.

Don Young