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  2. HVAC control system - Wikipedia

    en.wikipedia.org/wiki/HVAC_control_system

    HVAC (Heating, Ventilation and Air Conditioning) equipment needs a control system to regulate the operation of a heating and/or air conditioning system. [1] Usually a sensing device is used to compare the actual state (e.g. temperature) with a target state. Then the control system draws a conclusion what action has to be taken (e.g. start the ...

  3. Reversing valve - Wikipedia

    en.wikipedia.org/wiki/Reversing_valve

    A reversing valve removed from an HVAC heat pump for replacement. A reversing valve is a type of valve and is a component in a heat pump, that changes the direction of refrigerant flow. By reversing the flow of refrigerant, the heat pump refrigeration cycle is changed from cooling to heating or vice versa. This allows a residence or facility to ...

  4. Thermal expansion valve - Wikipedia

    en.wikipedia.org/wiki/Thermal_expansion_valve

    A thermal expansion valve is a key element to a heat pump; this is the cycle that makes air conditioning, or air cooling, possible. A basic refrigeration cycle consists of four major elements: a compressor, a condenser, a metering device and an evaporator. As a refrigerant passes through a circuit containing these four elements, air ...

  5. Thermal cutoff - Wikipedia

    en.wikipedia.org/wiki/Thermal_cutoff

    Flashing incandescent Christmas lights take advantage of this effect. Some flasher bulbs interrupt power when heated, while other twinkle/sparkle mini-bulbs momentarily shunt current around the filament. Thermal switches are part of the normal operation of older fluorescent light fixtures, where they are the major part of the starter module.

  6. Heating system - Wikipedia

    en.wikipedia.org/wiki/Heating_system

    Central heating systems: These systems produce heat in one central location and distribute it throughout the building. This category includes furnaces, boilers, and heat pumps. [1] [2] Distributed heating systems: These systems generate heat in the space they are to heat, without extensive duct systems. Examples include electric space heaters ...

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  8. Heating, ventilation, and air conditioning - Wikipedia

    en.wikipedia.org/wiki/Heating,_ventilation,_and...

    Electrical heaters are often used as backup or supplemental heat for heat pump systems. The heat pump gained popularity in the 1950s in Japan and the United States. [14] Heat pumps can extract heat from various sources, such as environmental air, exhaust air from a building, or from the ground. Heat pumps transfer heat from outside the ...

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