# What is a Joule?

A. The joule is defined as a unit of energy used to measure the distance a given weight can be moved in a unit of time or the amount of heat produced in a resistor by electrical current. The joule is commonly described as one watt second. The joule does not measure the effectiveness or safety of electric shock.

A joule (J) is the unit of energy used in the International System of Units (SI). It is named after English physicist James Prescott Joule, who developed the theory of conservation of energy and the first law of thermodynamics in the 19th century. Following SI conventions, joule is abbreviated with a capital J because the term is derived from a proper name, though if spelled out, it is not capitalized. A joule is defined as the amount of energy expended by a force of one newton moving an object one meter in the same direction as the force. The above definition of a joule may sound complicated, but the great thing about SI units is that they can all be defined in terms of grams, meters, and seconds, familiar concepts to most people. A joule can therefore be defined by the equation J = kg (m2/s2). While James Prescott Joule first discovered the value of the joule through his work on heat and mechanical work, Dr. Mayer of Heilbronn introduced the term. The term newton-meter (N.m) is inter

Note: Outside of the U.S. and some other places, BTUs is being replaced with the SI unit of energy, the Joule. (J). The English have beaten out the Scots by James Prescott Joule who defined this value. since there are 3600 seconds in an hour) the following formulas equating Watts, Joules, and Newton meters can be written: 1 Watt second (Ws) = 1 joule (J) = 1 newton meter 1 Watt hour (Wh) = 3600 Joules 1 kilowatt hour = 3.6 x 106 Joules, since there are 1000 watts in a kilowatt. We can think of an air conditioner’s “efficiency” as expressed either in the total operating cost for a season of use, or you may prefer to just express the air conditioner’s efficiency as its operating cost to run the system for one hour. The equation shown at page top is designed to reduce all of the parameters describing air conditioning efficiency to a single efficiency number, SEER. SEER numbers are useful when we’re comparing one air conditioner with another. But suppose we want to know the actual air cond