Average horsepower per cfm
Average horsepower per cfm
(OP)
Does anyone have a general formula for estimating horsepower (bhp) requirements per cfm?
I'm just looking for a rough number for estimating the fan motor horsepower on a large number of fan coils, and I would like to avoid selecting 150 fans at this point just to determine what the approximate bhp would be.
Any tips would be greatly appreciated.
I'm just looking for a rough number for estimating the fan motor horsepower on a large number of fan coils, and I would like to avoid selecting 150 fans at this point just to determine what the approximate bhp would be.
Any tips would be greatly appreciated.





RE: Average horsepower per cfm
For small fan coil units efficiency would probably be in the 0.40 to 0.50 range. Larger, more efficient units would be around 0.65. Check catalogs & solve for efficiency.
Total pressure would be external static + coil pressure drops + filter pressure drop.
RE: Average horsepower per cfm
RE: Average horsepower per cfm
Good point. I think that factor is a function of air density, which can vary significantly depending on altitude and, to a lesser degree, temperature. But either value works for a rough estimate.
ko (www.ecooling.biz)