Air distribution

[herschmidt]

I have a 4000 sq ft retail space, and there are 2 roof top units of 5 Tons each one, this place is going to be an office place, the offices have different dimensions.

My question is How do I calculate the CFM's for each office?

Thanks.

Hernan

 

[trashcanman]

Calculate the sensible heat gain/loss for each space. CFM is approx = space sensible gain/(20*1.08) (assuming supply air temp is 20 cooler than space design temp).

 

[LSA]

Here is some rule of thumb that may help.

One nominal ton of Air conditioning = 12,000 BTUH

One nominal ton of Air conditioning = 400 CFM

Standard Office Building CFM per square feet = 1 to 1.2

Standard Office Building square feet per ton = 333 to 400

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So your 5 ton unit has a nominal CFM of 2,000 CFM.