Search results
Results from the WOW.Com Content Network
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 ...
The majority of guidance available for design of heat and smoke building vents installed in buildings is restricted to nonsprinklered, single-story buildings. [4] This is partly a historical consequence of the installation of heat and smoke vents following the August 1953 General Motors, Livonia, MI major fire in a nonsprinklered manufacturing facility which effectively stopped the production ...
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.
Ventilation is a part of structural firefighting tactics, and involves the expulsion of heat and smoke from a burning building, permitting the firefighters to more easily and safely find trapped individuals and attack the fire. It is frequently performed from the outside of a burning building while the fire is being extinguished on the inside.
Four wires come to the centrally-located thermostat from the main heating/cooling unit (usually located in a closet, basement, or occasionally in the attic): One wire, usually red, supplies 24 volts AC power to the thermostat, while the other three supply control signals from the thermostat, usually white for heat, yellow for cooling, and green ...
Ventilation is mainly used to control indoor air quality by diluting and displacing indoor effluents and pollutants. It can also be used to control indoor temperature, humidity, and air motion to benefit thermal comfort, satisfaction with other aspects of the indoor environment, or other objectives.
A register's damper provides a critical function. Primarily, the damper allows the amount of hot or cool air entering a room to be controlled, providing for more accurate control over room temperature. [7] Dampers also allow air to be shut off in unused rooms, improving the efficiency of the HVAC system.
Control of the system's fan capacity is critical in VAV systems. Without proper and rapid flow rate control, the system's ductwork, or its sealing, can easily be damaged by overpressurization. In the cooling mode of operation, as the temperature in the space is satisfied, a VAV box closes to limit the flow of cool air into the space.