Drawing Specification Worksheets

Note: These forms must be filled out in Adobe Reader or Adobe Acrobat, not within your web browser. To download, right-click on a link and choose “Save Target As” or “Save Link As”. Once downloaded, double-click on the form to open it in Adobe Reader or Adobe Acrobat. Fill out the form, save it, and send it as an email attachment to

Operating Condition Worksheets

Common Formulas

Face Area (ft2): FA = FH x FL / 144
Face Velocity (fpm): FV = SQEM / FA
Heating Applications: SH = 1.085 x SCFM x (DBL – DBE)
GPM = SH / 500 x (EWT – LWT)
Cooling Applications: TH = 4.5 X SCFM X (HE – HL)
SH = 1.085 x SCFM x (DBE – DBL)
GPM = TH / 500 X (LWT – EWT)

Where: DBE = Entering air dry bulb (°F.)
DBL = Leaving air dry bulb (°F.)
EWT = Entering water temperature (°F.)
FA = Coil face area (ft2)
FH = Finned height (in.)
FL = Finned length (in.)
FPM = Feet/minute
FV = Face velocity (fpm)
GPM = U.S. gallons/minute of water
HE = Enthalpy of entering air (BTU/lb.)
HL =Enthalpy of leaving air (BTU/lb.)
LWT = Leaving water temperature (°F.)
SCFM = Standard cubic feet/minute of air
SH = Sensible heat (BTU/hour)
Total heat (BTU/hour)

Note: On Cooling Applications with dehumidification (wet coils), the face velocity should not exceed 500 fpm to prevent water-carryover from the coil.