Variable Air Volume Box with Hot Water Reheat – The variable air volume box or VAV box is a commercial solution to adding multiple zones to large buildings. VAV boxes offer zoning solutions so that separate zoning demands or temperature selections can be maintained in different areas of the building.
If the president of the company wants the temperature in their office to be 70 degrees Fahrenheit but the vice president wants their office to be 74 degrees Fahrenheit then it is possible with the VAV zoning system as long as their VAV boxes are on different zones.
Variable Air Volume Box with Hot Water Reheat
This particular VAV box in the picture is not fan-powered. It relies on York VAV Air Handlers | HVAC Zoning the main VAV air handling unit to provide all the air. Generally, when a fan-powered VAV box is calling for heat the damper inside the VAV box closes down so that minimal CFM’s are coming through the primary duct from the air handler. The fan turns on and pulls air from the plenum space above the ceiling.
This plenum air is normally warmer than the air inside the occupied space. The heating system kicks in and adds heat to the air until a set point is attained. The heat for a VAV box can typically be a hot water coil or electric heat strips. The VAV box in the picture has hot water reheat and is controlled by a building automation system or DDC.
Building automation systems are capable of being linked to the internet for remote control and monitoring which adds many beneficial factors for managers and technicians of commercial property. A single building can have several hundred VAV boxes and with a DDC system managers can quickly see where problem areas are or change control set points with a few clicks. VAV Boxes are perfect for HVAC zoning systems in commercial buildings. You can see how VAV boxes work here.
Variable Air Volume Box with Hot Water Reheat