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An attic fan installed underneath a roof. A powered attic ventilator, or attic fan, is a ventilation fan that regulates the heat level of a building's attic by exhausting hot air. A thermostat is used to automatically turn the fan off and on, while sometimes a manual switch is used. An attic fan can be gable mounted or roof mounted. Additional ...
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 ...
Infrared heating uses infrared lamps, commonly called heat lamps, to transmit infrared radiation to the body that is being heated. When a body with a large surface area needs to be heated, an array of infrared lamps is often used. The lamp commonly contains an incandescent bulb that produces infrared radiation.
An infrared heater or heat lamp is a heating appliance containing a high-temperature emitter that transfers energy to a cooler object through electromagnetic radiation. Depending on the temperature of the emitter, the wavelength of the peak of the infrared radiation ranges from 750 nm to 1 mm.
Mechanical ventilation is often provided by equipment that is also used to heat and cool a space. Natural ventilation is the intentional passive flow of outdoor air into a building through planned openings (such as louvers, doors, and windows). Natural ventilation does not require mechanical systems to move outdoor air.
As these need to operate in any orientation, they use a different mechanism rather than a float. The hygroscopic vent system uses hygroscopic cellulose fibre discs. [7] These are small discs of material that expand when wet and shrink if warm and dry. A dry valve acts as an air vent until a dribble of water passes through it and swells the ...
A register is a grille with moving parts, capable of being opened and closed and the air flow directed, which is part of a building's heating, ventilation, and air conditioning (HVAC) system. The placement and size of registers is critical to HVAC efficiency. Register dampers are also important, and can serve a safety function.
One common code requirement is that the total area of attic vents be equal to or greater than 1/150 of the floor area of the attic, with 50 percent or more of the vent area located in the upper portion of the attic. Vents and louvers should face away from prevailing winds to keep out driven rain. Soffit vents under the eaves normally provide ...