BTU (British Thermal Unit)

Definition

The unit of thermal energy used in the US water treatment industry, defined as the heat required to raise one pound of water by one degree Fahrenheit.

One BTU is roughly the energy of a single burning wooden match, so it takes one match to heat one pound of water by one degree F. It anchors specific heat capacity, where water equals 1.0 BTU/lb per degree F and most metals sit near 0.1. It also converts to refrigeration capacity, with 12,000 BTU per hour equal to one ton of refrigeration.

Related concepts

Heat Load · Specific Heat Capacity · Ton of Refrigeration

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Part of The Blueprint of Water · 📏 measurement