CFM = Sensible Heat Load (Btu/hr) / (1.08 * ΔT)
=B2/(1.08*20) – assuming B2 holds the sensible heat load. 3. Duct Sizing (Equal Friction Method) Using the equal friction method (e.g., 0.08 to 0.12 in. w.g./100 ft), you can size ducts using a friction chart approximation. hvac design calculations excel
Flow Rate (GPM) = 24 * Q (Tons of Cooling) / ΔT (°F) CFM = Sensible Heat Load (Btu/hr) / (1