HeatWise HVAC HeatWise
Free tools

Free calculators for engineers

Our main product is our load calculation software, but we also build a handful of free tools for everyday HVAC work.

Psychrometrics Calculator

Calculate psychrometric properties of air — humidity, enthalpy, dewpoint and more. Built for engineers and technicians working with air-conditioning systems.

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Affinity Laws Calculator

Apply fan and pump affinity laws to find changes in airflow, static pressure and power when varying speed. Useful for system balancing and energy analysis.

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Hydronics Calculator

Calculate pipe pressure drop, flow rates and fluid temperatures for hot- and chilled-water systems. Handy for design and troubleshooting.

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Ductulator

Size rectangular and round ducts by calculating airflow, velocity and pressure drop — a go-to tool for duct sizing in HVAC design.

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