BTU to Therm Converter

A British Thermal Unit (BTU) is a unit of energy equal to approximately 1,055 joules. It represents the amount of energy needed to raise the temperature of one pound of water by one degree Fahrenheit at standard atmospheric pressure.

The BTU was developed in the 19th century as part of the British Imperial system for measuring heat energy. It became standard in heating, ventilation, and air conditioning (HVAC) applications in countries using imperial units, particularly for rating heating and cooling equipment capacity.

BTUs are extensively used in the United States for HVAC system ratings, heating and cooling equipment specifications, and energy content of fuels. They're standard for furnace output ratings, air conditioner capacity, water heater specifications, and natural gas energy content measurements.

A therm (thm) is a unit of energy equal to 100,000 BTUs or approximately 105.5 megajoules. It's commonly used for measuring natural gas consumption and energy content in the United States gas industry.

The therm was introduced in the early 20th century by the gas industry in the United States as a convenient unit for measuring and billing natural gas consumption. It provided a practical scale for residential and commercial gas usage where BTUs would result in large numbers.

Therms are primarily used in the United States for natural gas billing, gas appliance ratings, and energy content specifications for natural gas. They're found on residential and commercial gas bills, used in gas utility planning, and for measuring heating energy consumption.