Field Engineering Toolbox

HVAC Unit Converter (BTU, Tons, Watts, CFM, Pressure)

Convert cooling tonnages, airflow CFM, duct static pressures, and temperature differentials on-site in real time. ACCA and ASHRAE standard engineering conversion factors.

Capacity BTU / Tons / kW
Pressure PSI / in. W.C. / Bar
Airflow CFM / m³/h / L/s
Formula: 1 Ton = 12,000 BTU/hr = 3.51685 kW = ~400 CFM Airflow

Cooling Tonnage vs. BTU & Airflow CFM Matrix

Quick reference guide for nominal residential and commercial equipment:

Nominal Tonnage Cooling Capacity (BTU/hr) Electrical Power Equivalent (kW) Target Standard Airflow (CFM)
1.0 Ton 12,000 BTU/hr 3.52 kW 400 CFM
1.5 Tons 18,000 BTU/hr 5.28 kW 600 CFM
2.0 Tons 24,000 BTU/hr 7.03 kW 800 CFM
2.5 Tons 30,000 BTU/hr 8.79 kW 1,000 CFM
3.0 Tons 36,000 BTU/hr 10.55 kW 1,200 CFM
3.5 Tons 42,000 BTU/hr 12.31 kW 1,400 CFM
4.0 Tons 48,000 BTU/hr 14.07 kW 1,600 CFM
5.0 Tons 60,000 BTU/hr 17.58 kW 2,000 CFM
7.5 Tons 90,000 BTU/hr 26.38 kW 3,000 CFM
10.0 Tons 120,000 BTU/hr 35.17 kW 4,000 CFM

HVAC Units & Conversions FAQ

Why is 1 Ton of refrigeration defined as 12,000 BTU/hr?

One ton of refrigeration represents the amount of heat energy required to melt 2,000 pounds (one short ton) of ice at 32°F in 24 hours (2,000 lbs × 144 BTU/lb latent heat of fusion = 288,000 BTU / 24 hrs = 12,000 BTU/hr).

What is the difference between CFM and FPM?

CFM (Cubic Feet per Minute) measures total air volume flow rate. FPM (Feet per Minute) measures the linear velocity or speed of the air moving through a duct or grille (Velocity FPM = CFM / Area in sq. ft.).

Is this converter accessible directly on the job site without internet?

Yes. The ACLogics mobile app for iPhone and Android includes all capacity, airflow, pressure, and temperature conversion tools locally on your device with 100% offline access.

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