HVAC reference

BTU Conversion Reference

Core energy and capacity relationships used in BTU-based HVAC specifications.

Created · Updated

Scope and source

Use this page to check unit relationships. Btu energy values use the International Table Btu shown in NIST Federal Standard 376B; refrigeration tons use the 12,000 BTU/h convention used by U.S. DOE materials.

1 Btu1.055056 kJ
1 BTU/h0.29307107 W
1 kW3,412.141633 BTU/h
1 RT12,000 BTU/h

Formula

W = BTU/h × 0.29307107
BTU/h = kW × 3,412.141633
RT = BTU/h ÷ 12,000

Units and symbols

TermMeaningUse
BtuEnergyTotal heat quantity
BTU/hHeat-transfer rateHVAC capacity
RTRefrigeration tonCooling capacity shorthand

Lookup table

BTU/hkWRT
12,0003.5171
24,0007.0342
36,00010.5513

Related tool

Sources