BTU per Hour to Foot-Pound per Minute Converter

BTU/hr and ft·lbf/min in Practice

BTU per hour (BTU/hr) is the standard American unit for thermal power — the rate at which heat is added to or removed from a system. HVAC equipment such as air conditioners, furnaces, and heat pumps are rated in BTU/hr. A typical residential air conditioner produces 12,000 BTU/hr (one "ton" of cooling).

Foot-pound per minute (ft·lbf/min) measures the same quantity — power — but as mechanical work per unit time. Engineers occasionally need this form when working with older American textbooks or when combining thermal and mechanical power budgets in the same calculation.

The conversion follows directly from the definition of a BTU: 1 BTU equals approximately 778.169 foot-pounds of mechanical energy. Because one hour contains 60 minutes, dividing 778.169 by 60 gives 12.9694 ft·lbf per minute for every BTU per hour.

For reference: 1 mechanical horsepower equals 33,000 ft·lbf/min, so a 12,000 BTU/hr air conditioner produces roughly 12,000 × 12.9694 / 33,000 ≈ 4.7 horsepower of equivalent mechanical power.