I would like to know what is the largest air conditioner I can get for my apartment building. I have a 5 ton trane unit but it does not cool sufficiently on days when the temperature is above 90 degrees. The unit is only cooling one apartment (1500 sq. ft.) I was told that 5 ton is the largest residential unit that I could buy. I was told that if I need a larger unit I would have to purchase a rooftop unit. Is this true?

 

I have a 5 ton trane unit but it does not cool sufficiently on days when the temperature is above 90 degrees. The unit is only cooling one apartment (1500 sq. ft.)

Is this for real????? How would you rework the duct

ED

 

Unless you live in a tent outside of Bagdhad, it is quite unlikely that a 5 ton AC is cooling just one apartment.

Sizing need to be done on site by a qualified contractor who will calculate sq. ft, glass in windows and door, insulation, exposures, etc. Arbitrarily "tossing in" a large unit is a recipe for problems. In the first place, your forced air unit and duct work will not necessarily accept more tonnage. Secondly, if you overzize your unit, it will lead to short-cycling, inadequate moisture removal, etc.

The direct answer to your question is that 5 tons is the largest commonly used split unit for residential. Larger units don't necessarily have to be on the roof, but the size and noise often dictate that. In residential, what is more common for a very large house is that you install multiple units in the under-5 ton category.

You should have someone check out your system. It may need to be repaired, rather than replace.

 

Thanks Salesguy,

I think the problem might be my duct work. My building is about 90 years old and the roof is flat tar. It gets really hot on sunny days. I did have a qualified contractor install the unit (four seasons) and the 5 ton is what they suggested.

 

I still dont get what you have there for that load. But if thats what you need . Do like we do lots of time. Put duct work in for 10 tons AC. lock 2 -5 ton units to the same duct with both blowers together and a 2 stage tstat for the AC Works like a deam.

ED

 

5 tons for an appartment? My appartment is 1,286 sq. feet and i have a 1.5 ton unit. Large houses over 2000 sq feet have 5 ton units, not appartments.

 

I agree with the guys, 5 tons for 1,500 sq ft!? that's huge.

I have an older home that is 1,800 sq ft, and have 2ton A/C.

They do a heat load? Is the duct sized to handle that much air flow (2,000+ cfm)????

If it's the duct problem now, bigger tonnage IS NOT going to make it better, matter of fact, worse.

Ask the dealer for a Manual J and D results.

As for the roof, do you have any insulation up there?

 

No insulation.

 

With cost of energy going up, I'd spend the money and insulate the place. There is no point of wasting money on energy that will be lost in a minute.

Where are you at?

 

I live in Chicago