how much ac do i need .....


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Old 03-05-11, 01:30 PM
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how much ac do i need .....

I am located in the NYC area I have a room thats 24' x 26' and 9' high, well insulated and has exterior walls on 3 sides how much AC do I need to cool this area? How many registers? All guestimates are appreciated.
 
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Old 03-05-11, 03:50 PM
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Call a contractor and have a heat load calculation done. Or google heat load calculation and input the numbers yourself. Can not tell you how many tons of cooling you need over the internet there are too many variables
 
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Old 03-05-11, 04:03 PM
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I did it for the heating, its 26,000 btu at design temperature 72 degrees.
 
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Old 03-05-11, 04:07 PM
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ok, and cooling? usually done using the same calculator. Heating should be one value and cooling another value.
 
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Old 03-05-11, 04:59 PM
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Sorry, I dont see any for cooling, this is a Slantfin calculator.
 
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Old 03-05-11, 05:11 PM
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Old 03-15-11, 08:33 AM
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OK, so I did the calculation and it came back about 18,000 btu.

I read somewhere that I should use one supply for each window and each door,
I have 3 outside walls with 3 windows and 2 patio glass doors, can't I get away with using 2 10" flex supplies?
 
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Old 03-15-11, 03:42 PM
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No ten inch flex can not handle 400 cfm
 
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Old 03-16-11, 08:29 PM
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I decided and installed 3 - 10" flex ducts, can someone tell me what size return I need? Thanks for all your comments.
 
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Old 03-29-11, 03:35 PM
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That is a very small sf area

We don't know what kind of Return Air setup you have.

Does it require a duct run; how long a run?

You can oversize a RA, it only lowers the total ESP & improve efficient airflow.
Extra large filter areas also help. What size is the filter area going to be?

If a 1.5-Ton Unit; figure 700-CFM / 550-fpm Velocity= 1.2727272-sf of duct area, or 183-sq.ins.

A 14" Rd Metal duct provides 154-sq.in area, 16" if flex duct & stretched tight.
 

Last edited by HVAC RETIRED; 03-29-11 at 03:39 PM. Reason: If a 1.5-Ton Unit
 

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