Compile the manufacturer-rated pressure drops for all components housed inside or inline with the air stream. Ensure you use the "dirty filter" pressure drop specification rather than the "clean filter" drop to ensure the system can deliver design airflow over its entire maintenance cycle. 4. Automation and Advanced Excel Features
Tip: Refer to the ASHRAE Duct Fitting Database for accurate C₀ values. Step 4: Include Equipment Pressure Drops
Use a distinct background color (like light yellow) for cells requiring manual entry. Use a different color (like light grey or clear) for automated formula cells.
Create a table with the following column headers to track the index run (the longest, most restrictive path of the duct system): (Dropdown: Supply / Return) Section ID: (e.g., S1, S2, R1) esp calculation hvac excel sheet
Often have stronger blowers that can handle up to in. W.G. or higher.
is the sum of the pressure losses on the supply side and the return side of the system [1]. Why ESP Calculation Matters
Do not assume the physically longest duct run is the index path. A shorter run with multiple acoustic linings, tight elbows, and VAV boxes often creates higher static pressure than a long, straight run. Automation and Advanced Excel Features Tip: Refer to
Often have double the friction of rigid sheet metal due to sagging.
Fire Damper / Smoke Damper (typically 0.03 to 0.07 in. w.g.) VAV Box (minimum operating pressure drop) External Louver (for fresh air or exhaust systems) 5. Programming the Excel Formulas
Should we include a formula? AI responses may include mistakes. Learn more Share public link Create a table with the following column headers
The filter is often the highest source of resistance. Return Grilles: Filter grilles or standard return grilles. 3. How to Calculate TESP (The Formula)
An is an essential tool for HVAC designers and technicians to ensure that a selected fan or air handling unit (AHU) can overcome the resistance of the ductwork system to deliver the required airflow .
This formula adapts the standard HVAC air friction equation: =0.10913 * (C12^1.852) / (G12^4.867) Use code with caution. 4. Summary and Safety Factor Implementation