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  2. Central heating - Wikipedia

    en.wikipedia.org/wiki/Central_heating

    This limit controller may shut the furnace off if the blower fails or if something is blocking the air flow. The heated air is then sent back through the home through supply ducts. In larger commercial applications, central heating is provided through an air handler which incorporates similar components as a furnace but on a larger scale.

  3. List of valves - Wikipedia

    en.wikipedia.org/wiki/List_of_valves

    Saddle valve: where allowed, is used to tap a pipe for a low-flow need; Schrader valve: holds the air inside automobile tires; Security valve, a type of automatic shut-off valve (ASV): used to stop the flow of natural gas upon sudden pressure changes. Increased pressure or decreased pressure closes the valve (without using any external power ...

  4. HVAC control system - Wikipedia

    en.wikipedia.org/wiki/HVAC_control_system

    After the control of air flow and temperature was standardized, the use of electromechanical relays in ladder logic to switch dampers became standardized. Eventually, the relays became electronic switches, as transistors eventually could handle greater current loads. By 1985, pneumatic controls could no longer compete with this new technology ...

  5. Heating, ventilation, and air conditioning - Wikipedia

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

    Such a system contains a boiler, furnace, or heat pump to heat water, steam, or air in a central location such as a furnace room in a home, or a mechanical room in a large building. The heat can be transferred by convection, conduction, or radiation. Space heaters are used to heat single rooms and only consist of a single unit.

  6. Pressure switch - Wikipedia

    en.wikipedia.org/wiki/Pressure_switch

    Murphy oil pressure gauges with switches that activate on low pressure. A pressure switch is a form of switch that operates an electrical contact when a certain set fluid pressure has been reached on its input. The switch may be designed to make contact either on pressure rise or on pressure fall.

  7. Damper (flow) - Wikipedia

    en.wikipedia.org/wiki/Damper_(flow)

    This damper can switch the electrical power to control additional "slave" dampers, minimizing the electrical load on the damper's control circuitry and power transformer A zone damper (also known as a Volume Control Damper or VCD ) is a specific type of damper used to control the flow of air in an HVAC heating or cooling system.

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    mail.aol.com

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  9. Reversing valve - Wikipedia

    en.wikipedia.org/wiki/Reversing_valve

    Reversing valves are built into the heat pump by the manufacturer, and must be replaced by an HVAC technician if they fail. Since the valve is an integral part of the sealed refrigerant circuit, proper procedures for recovering and then later refilling the refrigerant must be followed, to prevent its loss into the atmosphere.