What is the US customary Unit for energry?

Question

Also it cannot be Watts.. Is it foot pound or british thermal unit? Or is it neither?

Answer 1

All three, BTU, ft-lb and kilowatt-hour are in common use in the US. Evenr though all three are measures of energy. we tend to use BTU for heat, ft-lb for mechanical energy and kilowatt-hours for electrical energy. The definiton of a watt as electrical is so ingrained here that many find it odd to specify engine or motor power in watts instead of horsepower. Horesepower-hour is sometimes used as an energy unit, too.

In cooling applications the unit of ton is even still used. It is a power equal to the cooling of 1 ton of ice melting in 24 hours -- that's 3.5 kW.

Answer 2

First of all, a watt is a measure of power, not energy. (A watt is a Joule per second. Joule is a measure of energy and a watt is a measure of how quickly energy is being used). A foot-pound is a measure of torque (length times a force).

I consider the "customary unit" in the US for energy a joule. I know that is an SI unit (metric) however I think that anybody in the US that has a need to express a quantity of energy has the ability to understand and graduated to the metric system a long time ago. Those that resist the metric system tend to be construction workers, and other non-scientific people who only have a need for a few basic measurements (feet, miles, pounds, etc)

On a serious note, a BTU (British Thermal Unit) is a measure of energy, as is "foot-pound force". A foot-pound force indicates the energy required to apply a 1 pound force for 1 foot. Not to be confused with the other foot-pound which is a measure of torque.

Answer 3

The most commonly used measure is the kilowatt-hour. The units used depend on the application. Heating and cooling use the BTU or British thermal unit. Foot pounds are used in other applications.

Answer 4

Well, it can't be Watts because Watts are a measure of power not energy, but Watt/hour or more commonly, kWh is used, also as said before BTU is common in some fields.

EDIT: for what it's worth I just checked my electric bill and it was in kWh not mega joules.Also my water bill is in hundreds of cubic feet, not gallons or liters, so "customary" can vary a bit depending on the field.

Answer 5

British Thermal unit (BTU) still common in heating and cooling applications.

Answer 6

The UK is required under an EU directive to use metric but you'll still find people using Imperial measurements

Answer 7

BTU=board of trade unit

Answer 8

For electrical energy, it's usually Killowatt-Hours (which translates to 3.6 Mega-Joules).

HTH

Doug

Answer 9

I was taught to use Joules through college.

Answer 10

btu