HVAC Formulas

1 TR = 12000 BTU/Hr

1Watt=3.412 BTU/Hr

1TR=3.516 Watts

1Watt=Q x Cp x Dt
Where Q - Flow of water in Ltr/Sec
            Cp - Specific Heat of Water (4.186 J/g'C)
            Dt - Temp difference in 'C

1TR = (gpm x Temp Diff in 'F)/24

Sensible Heat (BTU/Hr) = 1.08 x Q x Dt
Where Q - Air Flow Rate in CFM
           Dt - Diff of Entering/Leaving Air Temperature in 'F

Latent Heat (Btu/Hr) = 0.6 x Q x Dg
Where Q - Air Flow Rate in CFM
            Dg - Diff of Entering/Leaving Air Moisture Content in gr/lb

Pump HP = ((gpm x Pump Head in ft) x ( 3960 x Eff)) x Sp. Gravity)

Fan HP = ((( CFM x St.Pressure in Wg) x ( 6356 x Eff)) x (Density of Air/Density of Std Air))