BTU to Gigajoule 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 gigajoule (GJ) is a unit of energy equal to one billion joules (10⁹ J). It represents large amounts of energy, commonly used for measuring building energy consumption, industrial processes, and fuel energy content.

The gigajoule became important with the growth of energy-intensive industries and the need to measure energy consumption in large buildings and facilities. It provided a convenient scale for energy auditing, HVAC system sizing, and industrial energy management in the latter half of the 20th century.

Gigajoules are commonly used in building energy analysis, HVAC engineering, industrial energy management, and fuel energy content specifications. They're standard for measuring annual energy consumption of large buildings, industrial process energy requirements, and natural gas energy content.