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  2. Heat recovery ventilation - Wikipedia

    en.wikipedia.org/wiki/Heat_recovery_ventilation

    Diagramatic operation of a thermal wheel Ljungström Air Preheater by Swedish engineer Fredrik Ljungström (1875–1964). A thermal wheel, also known as a rotary heat exchanger, or rotary air-to-air enthalpy wheel, energy recovery wheel, or heat recovery wheel, is a type of energy recovery heat exchanger positioned within the supply and exhaust air streams of air-handling units or rooftop ...

  3. 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 ...

  4. Heating, ventilation, and air conditioning - Wikipedia

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

    Rooftop HVAC unit with view of fresh-air intake vent Ventilation duct with outlet diffuser vent. These are installed throughout a building to move air in or out of rooms. In the middle is a damper to open and close the vent to allow more or less air to enter the space. The control circuit in a household HVAC installation.

  5. Glossary of HVAC terms - Wikipedia

    en.wikipedia.org/wiki/Glossary_of_HVAC_terms

    The study of the behavior of air-water vapor mixtures. Water vapor plays an important role in energy transfer and human comfort in HVAC design. rooftop unit (RTU) A packaged unit that controls both heating and air conditioning. An air handler typically refers to a unit that provides a fan to support either heating or cooling. radiant ceiling panels

  6. Seasonal energy efficiency ratio - Wikipedia

    en.wikipedia.org/wiki/Seasonal_energy_efficiency...

    In the United States, the efficiency of air conditioners is often rated by the seasonal energy efficiency ratio (SEER) which is defined by the Air Conditioning, Heating, and Refrigeration Institute, a trade association, in its 2008 standard AHRI 210/240, Performance Rating of Unitary Air-Conditioning and Air-Source Heat Pump Equipment. [1]

  7. Stack effect - Wikipedia

    en.wikipedia.org/wiki/Stack_effect

    The stack effect or chimney effect is the movement of air into and out of buildings through unsealed openings, chimneys, flue-gas stacks, or other purposefully designed openings or containers, resulting from air buoyancy.

  8. View factor - Wikipedia

    en.wikipedia.org/wiki/View_factor

    The view factor is then equal to the differential area dA i times the proportion of the unit circle covered by this projection. The projection onto the hemisphere, giving the solid angle subtended by A j , takes care of the factors cos(θ 2 ) and 1/ r 2 ; the projection onto the circle and the division by its area then takes care of the local ...

  9. Convection (heat transfer) - Wikipedia

    en.wikipedia.org/wiki/Convection_(Heat_transfer)

    where ˙ is the heat transferred per unit time, A is the area of the object, h is the heat transfer coefficient, T is the object's surface temperature, and T f is the fluid temperature. [8] The convective heat transfer coefficient is dependent upon the physical properties of the fluid and the physical situation.