Ventilation Fans
Ventilation fans are essential components of HVAC systems, as they circulate air and keep it fresh as it moves through the duct work air tunnels. Fans draw in new air from outside the system and also help to re-circulate returning air through a filter. Vent fans are positioned at strategic locations in walls, roofs and ceilings to either release heated or conditioned air to a room within a building or exhaust unhealthy air, fumes, smoke or dust to the outside. Vent fans work in conjunction with duct heaters and air conditioning systems, as they move the airflow through the heating or cooling elements or cooling towers. Fans may be directly or indirectly powered by a system's central air handling motor, or they may come with their own motor.
Ventilating fans, in the most simplistic terms, either suck air in or push air out at intake or outlet, return or departure HVAC vents. Axial ventilation and cooling fans offer maximum-volume linear airflow throughout a system. Centrifugal in-line duct fans offer a higher pressure flow through vents. Regenerative ventilation offers an integrated two-phase heating and cooling system for efficient air exchange. Ventilation blowers may also be single room units that could be stand-alone and/or portable - specific mobile units include marine and aircraft, and heavy duty ones prove highly effective in fire safety and fire fighting.