You would need a 2 ton unit to cool 1500Sqft, The unit sits outside and houses the compressor and condensor coil. You run power (220V, 25 amp breaker or fuse) and Thermostat wire. A 3" hole gets drilled in the wall and copper tubes run refrigerant to the A-coil that sits in the plenum in your furnace. R-22 runs through the A-coil and cools the coil, your fan in the furnace blows the cold air through your house. Because the A-coil goes from warm(room temp) to cold, it condensates.....if there's a drain near your furnace, the a-coil can drain there.....or you can use a condensation pump and run it outside.

As for the size of cooling coil, it goes by the unit....a 2 ton unit will use a 10 or 12 sear coil. You can also get a 10 or 12 seer H coil that will fit in smaller duct.

If I lived where you are, I could do the job for half what the AC specialists would charge.

Just so you know, a 2 ton unit costs the company about 700 bucks and the coil is around 200 bucks....well it is here anyway.

Oh yea, I used to work for Kool Enterprises in case anyone is wondering 905-623-3221

 

very interesting...definitely thanks for the info!

 

Listen to Brandon. Talking all techie I design these systems everyday. IMO a 2-ton is bare minimum for a 1500 sq. ft. house. Step it up to at least a 3-ton if you like it to feel chilly on the hot summer days. But again, it depends on your furnace.

Basically it breaks down like this: you want to size your coil in tons of cooling (not tons of weight lol) for 1-ton to every 400 cfm of fan capacity your furnace has. So if you have a 1000 cfm furnace, it should have a 2.5-ton coil. I know for the non-residential systems I design (commerical, industrial, institutional, etc) a rule of thumb is 1 cfm for every 400 sq ft but in the residential game that number could be as low as 1/2 cfm. That could be where Brandon got the 2-ton number from. Size it to your furnace fan capacity though.

R-22 is okay but when they end up banning it like they did for R-12, you might want to look at buying a unit with R417a refrigerant so know it'll have refrigerant available in the future. Don't bother with getting a heat pump. You have a furnace for heating so don't pay any extra for a heat pump over a straight air conditioner (cooling-only).

If you have a regular vertical up-flow furnace, then an A-coil should fit fine. They call it an A-coil because thats what it looks like: an A! lol

 

I was under the assumption that 1500Sqft was the whole house....if 1 floor is 1500sqft and there's still more house, than you'd probably go with a 4 ton unit depending on the square footage of the whole house.

I've been installing AC and refrigeration systems for a year now, but I was taught to figure out the size of a unit by square footage of the house or area you are cooling. ei: 800 Sqft requires a 1 ton unit. Which is where I got my numbers from.

An A-Coil is what you'd use for a upright furnace, however, some houses have a furnace that lays on it's side, like in a crawlspace......in that case the duct is usually smaller and you'd use an h-coil.

Also, I believe production on 10 seer coils has stopped...or it could be 12 seer, I can't remember (I work more on walk-in coolers and restauraunt fridges and coolers than central air).

Just FYI, I can still get R-12. I mostly work with 409 in industrial walkin coolers and restaurant coolers/fridges. I have a bunch of coolant at work....134a, 409, R22, R12 etc but I don't even use most of them.

Yea, if it gets banned it would certainly be better to use the latest refrigerant. But if you look at it from my shoes it's not so great.

I put in a new system, in 10-20 years I go out and charge it with whatever refridgerant it uses and I charge $200 or 150 if it's a cash deal.....OR I put in an R22 system, and when it gets banned all of a sudden I can't charge that system in 10-20 years so I charge around $2000 in labour to install a new system.

Sounds like a scam but unfortuantly that's how buisness is....and if you think that's bad, it's not, bigger companies charge WAY more than I ever would.

Yea, no need for a heat pump..I agree 100%

 

^ Your rule of thumb of a ton per 800sqfoot isn't wrong, it's just more residential where SUX comes from a commercial point of view. The codes, rules of thumb, and standards are all different from one to the other.

A keener would get right back to heat loads and actually calculate the cooling but chances are they would get right back to similar values to the rule of thumb anyway.

 

^ very true. Code does differ in different places, I think you guys are quite different from our codes but then again, I've never been out there. Definatly gotta be different codes for different areas, likely takes a lot more to cool a place in Ontario than in BC near the ocean. Just a guess though