Static Pressure Calculator
The Static Pressure Calculator is a tool used to estimate the Total External Static Pressure (TESP) that an HVAC system's fan must overcome. TESP is the sum of all resistances to airflow in the ductwork system, including filters, coils, duct sections, fittings, grilles, and diffusers. Accurately determining TESP is crucial for selecting a fan that can deliver the required airflow (CFM) for proper heating, cooling, and ventilation. This calculator allows users to input the pressure drop (in inches of water gauge) for each component in the system, and it sums these values to provide the TESP.
Measuring Static Pressure: Static pressure is typically measured in inches of water column (in. w.c. or "wg") using a manometer. Small test ports are drilled into ductwork or the air handler before and after components to measure pressure differences. TESP is a key diagnostic for system performance; high static pressure often indicates airflow problems due to restrictive ductwork, dirty filters, or undersized components, leading to reduced efficiency and comfort.
This tool performs a simple summation. Accurate TESP calculation requires careful determination of each component's pressure drop at the specific design airflow. Ductwork pressure drop should be calculated using tools like a ductulator or friction loss software (considering fittings). Consult ACCA Manual D or SMACNA guidelines for comprehensive system design.