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  2. British thermal unit - Wikipedia

    en.wikipedia.org/wiki/British_thermal_unit

    The British thermal unit (Btu) is a measure of heat, which is a form of energy. It was originally defined as the amount of heat required to raise the temperature of one pound of water by one degree Fahrenheit. It is also part of the United States customary units. [1] The SI unit for energy is the joule (J); one Btu equals about 1,055 J (varying ...

  3. Thermal transmittance - Wikipedia

    en.wikipedia.org/wiki/Thermal_transmittance

    Thermal transmittance. Thermal transmittance is the rate of transfer of heat through matter. The thermal transmittance of a material (such as insulation or concrete) or an assembly (such as a wall or window) is expressed as a U-value. The thermal insulance of a structure is the reciprocal of its thermal transmittance.

  4. Ton of refrigeration - Wikipedia

    en.wikipedia.org/wiki/Ton_of_refrigeration

    12,000.00 Btu IT /h. 2,593.90 ft⋅lbf/s. A ton of refrigeration (TR or TOR), also called a refrigeration ton (RT), is a unit of power used in some countries (especially in North America) to describe the heat-extraction capacity of refrigeration and air conditioning equipment. It was originally defined as the rate of heat transfer that results ...

  5. Cooling capacity - Wikipedia

    en.wikipedia.org/wiki/Cooling_capacity

    Cooling capacity. Cooling capacity is the measure of a cooling system's ability to remove heat. [1] It is equivalent to the heat supplied to the evaporator/boiler part of the refrigeration cycle and may be called the "rate of refrigeration" or "refrigeration capacity". As the target temperature of the refrigerator approaches ambient temperature ...

  6. List of thermal conductivities - Wikipedia

    en.wikipedia.org/wiki/List_of_thermal_conductivities

    Formula values d=1 centimeter Standard Atmospheric Pressure ... To make it easier a lb/ft 3 is about 0.01601846 grams/cm 3 and a Btu in./ft 2 hr °F is about 0. ...

  7. Cooling load temperature difference calculation method

    en.wikipedia.org/wiki/Cooling_load_temperature...

    The equations for the use of the data retrieved from these tables are very simple. Q= heat gain, usually heat gain per unit time. A= surface area. U= Overall heat transfer coefficient. CLTD= cooling load temperature difference. SCL= solar cooling load factor. CLF= cooling load factor. SC= shading coefficient.

  8. Heating seasonal performance factor - Wikipedia

    en.wikipedia.org/wiki/Heating_seasonal...

    HSPF is defined as the ratio of heat output (measured in BTUs) over the heating season to electricity used (measured in watt-hours). [1][2] It therefore has units of BTU/watt-hr. The higher the HSPF rating of a unit, the more energy efficient it is. An electrical resistance heater, which is not considered efficient, has an HSPF of 3.41.

  9. Thermal conductance and resistance - Wikipedia

    en.wikipedia.org/wiki/Thermal_conductance_and...

    In heat transfer, thermal engineering, and thermodynamics, thermal conductance and thermal resistance are fundamental concepts that describe the ability of materials or systems to conduct heat and the opposition they offer to the heat current. The ability to manipulate these properties allows engineers to control temperature gradient, prevent ...