7 Services from hvac-calc.x402tookit.com

Calculates air changes per hour (ACH) from airflow (CFM) and room volume, or computes the CFM needed to achieve a target ACH rate.

Calculates new airflow (CFM), static pressure, and shaft power after a fan speed change using the fan affinity laws (flow ∝ N, pressure ∝ N², power ∝ N³).

Calculates the mixed-air dry-bulb temperature and outside-air fraction when two airstreams (e.g. return air and outside air) are blended together.

Calculates sensible heat load in BTU/h (using 1.08 × CFM × ΔT) or the required CFM airflow for a given heat load and temperature difference

Calculates air velocity (FPM) and velocity pressure (in. wg) in a round or rectangular duct from CFM, or the CFM required to achieve a given velocity.

Converts between HVAC efficiency ratings (EER, COP, kW/ton) and cooling capacity units (tons, BTU/h, kW).

Calculates the equivalent round duct diameter for a rectangular duct (same friction loss), or finds the missing rectangular side that matches a given round duct diameter.