|
|
What is a BTU?
The British thermal unit (symbol BTU or Btu) is a traditional unit of energy equal to about 1,055.05585 joules. It is approximately the amount of energy needed to heat 1 pound (0.454 kg) of water from 39 °F (3.9 °C) to 40 °F (4.4 °C). The unit is most often used in the power, steam generation, heating and air conditioning industries.
A Btu is defined as amount of heat required to raise the temperature of one 1 pound (0.454 kg) of liquid water by 1 °F (0.556 °C) at a constant pressure of one atmosphere. As is the case with the calorie, several different definitions of the Btu exist, which are based on different water temperatures and therefore vary by up to 0.5%: A Btu can be approximated as the heat produced by burning a single wooden match or as the amount of energy it would take to lift a one-pound weight to a height of 778 feet (237 m).
Calculation: Wattage x 3.413 = BTUs
Example One: 1,000 watts x 3.413 = 3,413 BTUs
Example Two: 4,000 watts x 3.413 = 13,652 BTUs
The amperage of the unit will determine the wire size needed for the heater. The heating industry uses the American Wire Gauge (AWG) standard to classify electrical wire.
The AWG number indicates the diameter of conductor for the wire and correlates to the amperage that the wire can safely handle. The lower the AWG number, the higher the rating. The amperage of multiple heaters must be added if they are on the same circuit. If you are replacing an existing heater, match the amperage of the old heater.
Single Phase:
Amps = Watts/Volts
3 Phase:
Amps = Watts/Volts
|
|
|
|
|
