Convert Watts to BTU per Hour

The Watt (symbol: W) is a unit of power. The SI unit of power (ISO 80000-5 §5-19), defined as exactly one joule per second (1 W = 1 J/s = 1 kg·m²/s³ = 1 V·A in electrical systems). Named after Scottish mechanical engineer James Watt (1736-1819), whose late-18th-century improvements to the Newcomen atmospheric steam engine (separate condenser, sun-and-planet gear) launched the Industrial Revolution and made power-unit standardization economically necessary. The watt is the universal electrical and mechanical power unit across scientific publication, engineering, consumer electronics, and energy markets. Reference values: a typical 9 W LED bulb produces ~800 lumens (equivalent to a 60 W incandescent at 14 lm/W luminous efficacy); audio equipment output power (a hi-fi home amplifier 50-200 W per channel; a concert PA system 5,000-50,000 W); a modern crystalline-silicon residential solar PV module ~350-450 W peak per panel under STC; a household refrigerator continuous load ~150 W average; a high-end gaming PC at full load ~700 W; a Tesla Model S Plaid peak motor output ~760 kW (1,020 hp); the world's electricity-generating capacity ~8 TW (8 × 10¹² W).

It belongs to the metric measurement system.

Watts are commonly used in electrical systems, automotive performance, and HVAC sizing.

The BTU per Hour (symbol: BTU/hr) is a unit of power. An imperial unit of power (rate of heat transfer or thermal-energy flow), equal to ≈ 0.29307 watts per NIST SP 811 (= exactly 1/3,600 of 1,055.06 J/s in International Table form). BTU/hr is the dominant working unit for US HVAC equipment sizing per the ASHRAE Handbook, AHRI / NRCan / DOE equipment-rating standards, and the energy guide labels on every US-sold air conditioner, heat pump, water heater, and gas furnace. Reference values and the 'ton of refrigeration' convention: 12,000 BTU/hr ≈ 3.517 kW = exactly 1 'ton of refrigeration' (originally defined as the heat-removal rate to freeze 1 short ton of water in 24 hours); residential central-AC sizing 24,000-60,000 BTU/hr (2-5 tons); window AC 5,000-12,000 BTU/hr; mini-split heat pump 9,000-36,000 BTU/hr per indoor head; gas furnace input 40,000-100,000 BTU/hr residential / 200,000-500,000 BTU/hr light commercial; tank water heater 30,000-50,000 BTU/hr; tankless 150,000-200,000 BTU/hr; commercial natural-gas-fired boiler 0.5-50 million BTU/hr.

It belongs to the imperial measurement system.

BTU per Hour are commonly used in electrical systems, automotive performance, and HVAC sizing.