HVAC & Refrigeration Tools
Sizing calculators and contracts built for HVAC, refrigeration, and mechanical pros. All free, no signup required.
HVAC Service Agreement Generator
Build tiered HVAC maintenance plan contracts with the terms your customers expect
HVAC CFM Calculator
Calculate required airflow by room size & air changes, or by cooling tonnage
HVAC Duct Calculator
Size round & rectangular ducts from airflow, velocity & friction rate
HVAC Load Calculator
Estimate heating & cooling BTU and recommended AC tonnage by square footage
Refrigerant BTU Calculator
Size a walk-in cooler or freezer's cooling capacity from volume & temperature
About these HVAC tools
Sizing equipment and writing maintenance contracts are two of the most error-prone parts of an HVAC business — get the load or duct size wrong and you get callbacks; write a vague service agreement and you eat the cost of refrigerant. These free tools handle the field math and the paperwork in one place.
The CFM, Duct, and Load calculators size airflow, ductwork, and heating and cooling capacity from real inputs, and the Refrigerant BTU calculator sizes walk-in cooler and freezer loads. The HVAC Service Agreement Generator builds tiered maintenance-plan contracts with the terms customers expect. Treat the calculators as fast estimates for scoping and quoting — confirm critical sizing against a full Manual J and Manual D where code requires it.