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  2. Per-unit system - Wikipedia

    en.wikipedia.org/wiki/Per-unit_system

    Conversion of per-unit quantities to volts, ohms, or amperes requires a knowledge of the base that the per-unit quantities were referenced to. The per-unit system is used in power flow, short circuit evaluation, motor starting studies etc. The main idea of a per unit system is to absorb large differences in absolute values into base relationships.

  3. Air changes per hour - Wikipedia

    en.wikipedia.org/wiki/Air_changes_per_hour

    Air changes per hour, abbreviated ACPH or ACH, or air change rate is the number of times that the total air volume in a room or space is completely removed and replaced in an hour. If the air in the space is either uniform or perfectly mixed, air changes per hour is a measure of how many times the air within a defined space is replaced each hour.

  4. 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

  5. PPH - Wikipedia

    en.wikipedia.org/wiki/PPH

    Pound per hour (symbol pph), mass flow unit (used in aviation to measure fuel flow, for instance) Part per hundred (percentage) People per hour, a measure of the rate of flow of people moving past a fixed point or through a system; Propylphenidate, an analogue of methylphenidate

  6. Pound per hour - Wikipedia

    en.wikipedia.org/wiki/Pound_per_hour

    Pound per hour is a mass flow unit based on the international avoirdupois pound, which is used in both the British imperial and, being a former colony of Britain, the United States customary systems of measurement. It is abbreviated as PPH, or more conventionally as lb/h.

  7. Watt - Wikipedia

    en.wikipedia.org/wiki/Watt

    Power is the rate at which energy is generated or consumed and hence is measured in units (e.g. watts) that represent energy per unit time. For example, when a light bulb with a power rating of 100 W is turned on for one hour, the energy used is 100 watt hours (W·h), 0.1 kilowatt hour, or 360 kJ. This same amount of energy would light a 40 ...

  8. Thermal transmittance - Wikipedia

    en.wikipedia.org/wiki/Thermal_transmittance

    Although the concept of U-value (or U-factor) is universal, U-values can be expressed in different units. In most countries, U-value is expressed in SI units, as watts per square metre-kelvin: W/(m 2 ⋅K) In the United States, U-value is expressed as British thermal units (Btu) per hour-square feet-degrees Fahrenheit: Btu/(h⋅ft 2 ⋅°F)

  9. Full load hour - Wikipedia

    en.wikipedia.org/wiki/Full_load_hour

    Full Load hour is a measure of the degree of utilisation of a technical system. [1] [2] [3] Full load hours refer to the time for which a plant would have to be operated at nominal power in order to convert the same amount of electrical work as the plant has actually converted within a defined period of time, during which breaks in operation or partial load operation can also occur.