Exhaust Fan Sizing

[swoosh172]

Hi all, I am sizing an exhaust fan system for a 56x25x18 ft building. The building is basically wide open inside, made of 8 inch cmu and built up roof. I am trying to figure out the cfm needed for the exhaust fan to maintain a comfortable indoor temperature during the summer. Fan will be on the roof, pulling air through louvers on the side walls. Is this a simple air changes per hour thing, or is there a detailed formula? I was thinking 6 ac/h, but it should probably be more. Any help is appeciated.

 

[willard3]

Depends both upon what dry bulb/wet bulb conditions are outside and what temp you want to maintain inside....is it people inside the building?

 

[Wareagl487]

A little more info is need to answer adequately. Is there a process rejecting heat? Are people present? What goes on inside the building? Quick answer would be minimum exhaust requirements to meet ASHRAE outside air ventilation requirements for the space as categorized in the tables.

Andy W.

 

[Unotec]

Define summer/comfortable temperature and attend the points above.
A 35ºC summer will NOT cool the room to a comfortable temperature, unless you're breeding chickens

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