Search results
Results from the WOW.Com Content Network
This definition ultimately became the statement that 1 IT calorie is exactly 4.1868 J. [4] [8] The Btu is then calculated from the calorie as is done for the thermochemical definitions of the BTU and the calorie, as in International standard ISO 31-4 Quantities and units—Part 4: Heat and British Standard BS 350:Part 1:1974 Conversion factors ...
It was originally defined as the rate of heat transfer that results in the freezing or melting of 1 short ton (2,000 lb; 907 kg) of pure ice at 0 °C (32 °F) in 24 hours. [1] [2] The modern definition is exactly 12,000 Btu IT /h (3.516853 kW). Air-conditioning and refrigeration equipment capacity in the U.S. is often specified in "tons" (of ...
For gases, departure from 3 R per mole of atoms is generally due to two factors: (1) failure of the higher quantum-energy-spaced vibration modes in gas molecules to be excited at room temperature, and (2) loss of potential energy degree of freedom for small gas molecules, simply because most of their atoms are not bonded maximally in space to ...
For instance, a system which delivers an HSPF of 7.7 will transfer 2.25 times as much heat as electricity consumed over a season. [5] In Europe the term Seasonal Performance Factor ("SPF") is used to mean the same as the average COP over the heating season. A system which transfers 2.25 times as much heat as the electricity consumed is said to ...
1972 SM10310 model, 10,300 BTU/h, 115V 60 Hz, 7 1 ⁄ 2 amps, 860W, and EER of 12.0. It was once the most high-efficiency room air conditioner made by Friedrich. [10] QuietMaster: Professional grade room air conditioners manufactured from the 1976 until 2010, when it was replaced by the S/M/L chassis Kühl models. They were manufactured in ...
The volt-ampere (SI symbol: VA, [1] sometimes V⋅A or V A) is the unit of measurement for apparent power in an electrical circuit. It is the product of the root mean square voltage (in volts) and the root mean square current (in amperes). [2] Volt-amperes are usually used for analyzing alternating current (AC) circuits.
A packaged terminal air conditioner (PTAC) is a type of self-contained heating and air conditioning system intended to be mounted through a wall. [1] The first practical semi-portable air conditioning unit invented by engineers at Chrysler Motors. It entered the market in 1935, and was designed to fit under a window like many modern PTACs. [2]
Fig. 1 Fig. 2. A transformer supplying a three-wire distribution system has a single-phase input (primary) winding. The output (secondary) winding has a center tap connected to a grounded neutral. As shown in Fig. 1, either end to center has half the voltage of end-to-end.