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Eng Unit Converter

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Power

Popular:kW → HPHP → kWkW → PSW → BTU/hBTU/h → WMW → kWkW → RTRT → BTU/hMMBtu/h → MWHP → BTU/h
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Power Conversion Guide

Power is the rate of energy transfer or conversion per unit time. The SI unit is the watt (W), where 1 W = 1 J/s. Power tells you how fast energy is being consumed or produced, making it essential for sizing equipment. Key conversions: 1 HP (mechanical) = 745.7 W, 1 PS (metric HP) = 735.5 W, 1 BTU/h = 0.29307 W, 1 RT (ton of refrigeration) = 3,516.85 W = 12,000 BTU/h, 1 MMBtu/h = 293.07 kW. Power conversion is critical in motor selection, generator sizing, HVAC load calculations (cooling in RT, heating in BTU/h or kW), automotive engineering (engine output in HP or PS), and industrial process design. Key pitfalls: assuming HP and PS are identical (1.4% difference affects warranty specs), confusing the HVAC "ton" with mass tons, neglecting to account for efficiency when converting between input and output power, and mixing up kW (real power) with kVA (apparent power) in electrical systems where the power factor is less than 1.

! Power — Good to Know

  • Horsepower (HP) has multiple definitions: Mechanical HP = 745.7 W, Metric HP (PS/CV) = 735.5 W, Electric HP = 746 W. Up to 1.4% difference.
  • In HVAC, "ton of refrigeration" (RT) = 12,000 BTU/h = 3,516.85 W. The "ton" in cooling capacity has nothing to do with mass.
  • MMBtu/h is a heat rate unit used in large boilers, heaters, and LNG plants. 1 MMBtu/h ≈ 293 kW.

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