HORTICULTURE

Detailed explanation-1: -The British thermal unit, Btu, is another unit of heat used in the United States. One Btu is the amount of heat required to raise the temperature of 1 lb of water by 1°F.

Detailed explanation-2: -A British thermal unit (Btu) is a measure of the heat content of fuels or energy sources. It is the quantity of heat required to raise the temperature of one pound of liquid water by 1 degree Fahrenheit at the temperature that water has its greatest density (approximately 39 degrees Fahrenheit).

Detailed explanation-3: -A British Thermal Unit (BTU) is a measurement of heat energy. One BTU is the amount of heat energy required to raise one pound of water by 1ºF. Water weighs 8.33 pounds per gallon so we can calculate that one gallon of water requires 8.33 BTU to raise the temperature 1ºF.

Detailed explanation-4: -1 Btu = 252 cal = 1054 J. ((Definition)) 1 cal is defined as the heat necessary to raise the temperature of 1 g of water from 14.5 °C to 15.5 °C. ((Definition)) 1 Btu is defined as the heat required to raise the temperature of 1 lb of water from 63 F to 64 F.