Both these box equipment are used in the buildings to provide air. However, the specialties of both of them are somehow different to each other. The CAV stands for the Constant Air Volume, as the name suggests it provides a constant air inside a building. The air temperature is variable as it is directly coming from the control unit, but the flow of the air into a specific part of the building is constant throughout. The CAV boxes are mainly used in the small buildings as they are less expensive.
Whereas, the VAV box provides variable air inside a building. The temperature of the air is constant and similar as the control unit delivers. But the flow of the air into a particular part of a building is variable and being managed through these boxes. Usually they are used in the big buildings to better facilitate the people. They are expensive in cost though.
CAV System:
- It is cheaper in price.
- They are simple and sleek in design.
- They are also very reliable.
- They have on and off control system.
- Don’t contain the supply air modulation to vary the air temperature and flow.
VAV System:
- They are a bit expensive as compared to the CAV Systems.
- The fan noise is less and un-noticeable.
- It holds more precise temperature control.
- They contain the supply air modulation system to vary the air flow.
Working of the VAV System:
Basically, this VAV box is a metal sheet type of thing with dampers and controls. There is a thermostat inside the box, which monitors the temperature and then air flow is supplied accordingly. The controller and the thermostat are inter-connected. Whereas, the controller is responsible of varying the temperature and the flow of the air according to the temperature outside.
The input programs are set by the technical staff, so that the VAV system should not be overloaded. Once the temperature program is set, the working of this whole system starts. When the thermostat observes that the temperature of a room has raised or fall beyond the set module, it controls the temperature and flow of the air accordingly to keep a certain level intact.
The VAV box had made our lives easy and provided great relief. They are a great invention of this modern era, now we don’t have to manually adjust things. All that stuff can be done well by these systems.