# 1.5 ton vs. 2 ton VS cfm limitations



## intelliup (10 mo ago)

Hello! 

My square footage fall in between a 1.5 ton and 2 ton a/c unit.

I have a problem with getting enough CFM through the vents for a 2 ton, even though it might be the best for Texas summers. 

At 850 square foot, old, old insulation, 2 exterior walls east & south, single pain windows - I'm in between 1.5 & 2 tons. (1st floor Condo - neighbors above, and 2 sides)

2 ton maybe the better option, but the air handler calls for 840 - 880 cfm. No WAY I can get that in this condo. It'd be like a tornado in here!!

I have a ceiling mounted air handler (above the tub) that's in the center of the 1st story condo with 8 foot ceilings.

1 room is 12 x 11 and literally the vent is 1 foot from the plenum. 
2 room is the bathroom 4.5 x 7.5 (7.5" ceiling) the vent is directly IN the plenum
3 room is 12 x 11 and has a 9 foot run from plenum
4 room is the living dining kitchen combo, 22 x 20 with 3 ducts 
#1 vent is 4 inches from plenum
#2 vent is 10 foot from plenum
#3 vent is 18 foot from plenum and makes 2) 90 degree turns - the biggest duct that can fit the furlough space is 7 inch.

The way I figure it for comfort, the most cfm I can get is around 630cfm depending on how I go about the duct's sizing. That's okay for the 1.5 ton handler, but way short for the 2 ton.

Since my sq footage is right in the middle of needing a 1.5 and a 2 ton - wouldn't the 1.5 ton be the best for these circumstances?

Thank you so much!!


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## channellxbob (Sep 27, 2020)

There is a good argument for sticking to the smaller size in any install. A smaller unit will run a bit more and remove more moisture from the air which as we all know will make it feel cooler. I would definitely go 1-1/2T in this case. If it's true you cannot get 800cfm then a bigger unit does no good. Part of the capacity equation is volume of air. You aren't going to get 2T of cooling with 600cfm of air.


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## intelliup (10 mo ago)

channellxbob said:


> There is a good argument for sticking to the smaller size in any install. A smaller unit will run a bit more and remove more moisture from the air which as we all know will make it feel cooler. I would definitely go 1-1/2T in this case. If it's true you cannot get 800cfm then a bigger unit does no good. Part of the capacity equation is volume of air. You aren't going to get 2T of cooling with 600cfm of air.


Thank you soooo much for confirming my thoughts on the matter! I feel much better about it now.


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