CFM/TR and CFM/Sq.M

[Manu68]

Dear Experts,

Can you please let me know whether any high level ballpark figures that industry uses is available for quick estimation.

CFM per tonnage.
GPM/tonnage
CFM per Sq.M area or Tonnage/Sq.M at gross level.

I understand this will not be accurate but for a gut feel checking.

Best regards,
Manu

 

[MTES93]

Typically 400 CFM/TON ... more CFM/Ton if most of your cooling is sensible (dry), less CFM/Ton if you have more latent load. 400 CFM/Ton is the standard rating for most packaged equipment with a sensible heat ratio (sensible/total cooling) of around 0.8 or so...

Normally on the evaporator is 3.0 GPM/ton but this can be reduced with increased delta T.

Can I give you CFM/SF in lieu of SM? For most system (this is highly subjective) 0.7 to 1.2 CFM per square foot for standard offices. Obviously you don't want to use that if you have high internal or solar loads. You can get ton/SF based on number above and this range. I believe the industry standard is to use the inverse or square foot per ton... people don't like decimals!!!

Remember these are just estimates.

 

[willard3]

Also, remember that rules-of-thumb are not a substitute for thorough design.