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Heating & Air Conditioning

Adding central air conditioning to an existing furnace setup in attic

8 years ago

I live in a townhouse with 2 car garage in very
bottom(basement), a living room and kitchen over it(1st floor) and 2
bedrooms(2nd floor) over that.

Right now, I have a furnace that came with the house installed on
second floor with air handler and ducts done in early 80's. I have a
pretty spacious attic which previous owner put some plywood over to make
some space for storage.

I am planning to add central air conditioner to the existing setup.

Since it's a townhouse in a complex with no front-yard or backyard I
cannot put a condenser unit outside. Furnace is on 2nd floor, so putting
in basement/garage will involve a lot of tearing apart walls.

I have the corner unit, so I do have a small exhaust window from my
attic on left wall. I was thinking of putting my condenser unit next to
the window in the attic, so the hot air can easily exhaust out and It'll
be closer to the air-handler.

What I would like to know is :

1) Is this setup, to put the whole air conditioner unit in attic common practice ? Are there any drawbacks to it ?

2) How do I calculate if my attic can bear the load of a condenser
unit ? as far as i know, they are pretty heavy, i don't want my roof
collapsing on me while or after putting it in.

3) How big of unit do i need to put in ? My house is 1200-ish sq ft (600 x 2 floors).

4) How much does it usually costs ?

5) Where to buy / get installed the unit from ? (I live in Bay Area,
CA) Should I go for Sears, Costco, HomeDepot, Lowes or independent
contractors ?

6) Any tips and tricks to save some money during this whole project would be highly appreciated. :)

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Comments (5)

Elmer J Fudd
8 years ago
There are experts and others in the business who contribute here and can give you informed advice. I'm just a fellow homeowner but I believe A/C condensers in a split system need to be outside.
klem1
8 years ago
I've never heard of prohibiting the location of hvac equipment outdoors. Are you sure they won't alow condenser to sit on roof? I'll have to admit if your pockets were deep enough and Rater plus another gearhead or two joined up,I'd like to desighn an installation for a pak-unit or condenser in an attic. Not that I thought it was a good idea nor compare's to a small attic but I've installed a couple of condensers inside warehouses that worked well enough to get them by inside an office.
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tigerdunes
8 years ago
Totally opposed to using any big box store for HVAC...find a qualified dealer...tell us about your furnace-age, brand,size, Mdl number...since you live in location with moderate climate, I would think a 1 1/2-2 ton size...what do your neighbors do about AC and location of their outside condenser?

IMO
mike_home
8 years ago
I think installing a condenser in your attic would be a big mistake. It will perform poorly, noisy, and difficult to service.

Do any of the other townhouses have an outdoor condenser? Where is it located? A condenser can be installed above ground attached to the side of the building with a bracket. This is very typical for townhouses that have no adjoining land. You would install it at a height that you can walk under it, but not too high so it would be difficult to service.

I would think a 1 or 1.5 size unit for your house in the Bay area would be sufficient. You need a load calculation to determine the proper size. It is difficult to say how much it will cost given it is a new installation in a more difficult set up.

Stay away from the big box stores. Get estimates from independent dealers. You can save a little money when the temperatures are mild and rebates are offered.
tigerdunes
8 years ago
agree with Mike about installing condenser in an attic location....bad, bad idea...warranty would be voided...and I doubt you could even find a reputable dealer to do this...

IMO

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