Anyone know how to install central air?

Krassus

Golden Member
Jan 30, 2003
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A house we're buying doesn't have central air. Since i'm a contractor myself (exterior renovation), i'm considering putting central air in myself, as opposed to paying someone $10K+ to do it for me. I know there's not much to it, especially for someone who's used to doing things himself - i've installed everything from walls, to flooring, bathrooms, etc. But never this. So what i need right now is some sort of a technical manual - a way to teach myself how to do this. Does anyone have any suggestions?
 

Krassus

Golden Member
Jan 30, 2003
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Originally posted by: Pepsi90919
do you already have forced-air heat? if no then you might want to forget about it ;)
Are you asking if the house uses radiators for heating?
 

djheater

Lifer
Mar 19, 2001
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Originally posted by: Krassus
Originally posted by: Pepsi90919
do you already have forced-air heat? if no then you might want to forget about it ;)
Are you asking if the house uses radiators for heating?

He's asking because it should be relatively easy to throw the AC into the same ductwork as the furnace, however if you have to install the ductwork it would be considerably more difficult. Especially if you have multiple floors.

Dwscribe your heating situation.
 

Krassus

Golden Member
Jan 30, 2003
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There are no ducts in this house that i'm aware of. I believe the past owners were quoted $7K for the ducts alone.
 

Spamela

Diamond Member
Oct 30, 2000
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Originally posted by: Krassus
There are no ducts in this house that i'm aware of. I believe the past owners were quoted $7K for the ducts alone.

i worked in sheet metal/HVAC for several years during college.

putting in ductwork for a re-model is a job from hell.

if you put the stuff in an attic, then the temperature will be about 140 degrees &
you'll have to deal with insulation, dust, and the risk of falling through the ceiling.

if the house has a foundation, then there won't be much room to work &
you'll do a lot of belly crawling through dirt.

that said, you need to have a sheet metal shop fabricate a plenum
for the unit you'll buy, boxes for each outlet, and a return air box.
sheet metal snips are pretty cheap.
there are different varieties of ductwork - flexible & metal - each with their
pros & cons. you'll also have to buy Y's (splitters), registers, and possibly
ductwork insulation.
 

alkemyst

No Lifer
Feb 13, 2001
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It's not that difficult as much as it is just a PITA. It's hot, things are sharp, it's cramped, etc.

You first need to determine if you can get the ductwork in where you want it or if the ceiling has to come down in spots. (all this adds to the budget and time)

Then figure out how much cooling and 'drops' you need and the lengths/diameters of the ducting (when I was in engineering there was a book with all this info in a table, same way for fire sprinklers).

You will also need to find where you will put the intake vent and where you want the equipment to sit.

Then add up all those costs and shop around for an air unit capable and in the style you need some will hook this part up if you buy it from them for a minimal cost and complete the plenium for you (the part from the blower to the first duct in the house).

How big of a house will this be? if a simple 1000-1500 square foot 'box' type house, not so bad....for a 5k+ multilevel home it could be alot more difficult and you'd have to break out the lower level's ceiling.

 

Miramonti

Lifer
Aug 26, 2000
28,653
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Its being done on the first floor of the 2flat that I live in now (about 800sqft 2br unit). They've basically got the a/c unit in (put in closet), ducks in, as well as the framing to hold the drywall thats going to eventually hide encompass/hide it. They just have to finish the drywall, but most is still exposed.

If you want some pics lmk and I'll try to get some tonight.
 

alkemyst

No Lifer
Feb 13, 2001
83,769
19
81
lucky you had the ceiling height for it...will probably be really cool (bad pun).