Hvac Design Calculations Excel Exclusive May 2026

Velocity (FPM) = CFM / Area (ft²) . Add conditional formatting to highlight if velocity exceeds 1,500 FPM (noise risk) or 2,500 FPM (erosion risk). 4. Water Pipe Sizing (Hydronic Systems) For chilled or hot water systems, use:

CFM = Sensible Heat Load (Btu/hr) / (1.08 * ΔT) hvac design calculations excel

Flow Rate (GPM) = 24 * Q (Tons of Cooling) / ΔT (°F) Velocity (FPM) = CFM / Area (ft²)

Where ΔT is the temperature difference between supply and return air (typically 20°F for cooling). Water Pipe Sizing (Hydronic Systems) For chilled or

Heating, Ventilation, and Air Conditioning (HVAC) design is a numbers-driven discipline. From load estimation to duct sizing and water flow rates, accuracy is paramount. While dedicated software exists (like Carrier HAP or Trane Trace), Microsoft Excel remains an indispensable tool for engineers and technicians. Its transparency, customizability, and accessibility make it ideal for quick checks, iterative designs, and client-approved calculation sheets.

Store a friction loss vs. CFM vs. diameter table. Use INDEX/MATCH or linear interpolation to find the nearest duct diameter for a given CFM at your target friction rate.

=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.