What is a VAV system?

HVAC systems in commercial buildings are getting smarter every day. As technology advances, HVAC systems must adapt too. This growing “smart” building has brought huge benefits – energy management has tightened, tenant comfort has become more common, and cost savings have increased.

Let’s look at one smart HVAC system: VAV.

What is a VAV system?

VAV stands for Variable Air Volume. In its simplest form, a VAV system uses a changing airflow at a constant temperature to heat and cool a building. This is in contrast to CAV (or constant air volume) systems, which provide consistent airflow at different temperatures to heat or cool a space.

How does a VAV system work?

Let’s break down an example of how a VAV system works. The Air Handling Unit (AHU) pushes air through the ductwork at approximately 55 degrees Fahrenheit for cooling. The air temperature is kept constant in the system, moving through the ductwork to each area or room of the building. Air eventually reaches the end of each line and passes through the VAV box. Typically, a VAV box consists of a few simple parts: a damper, a controller/actuator, and maybe a coil for heating and cooling via electricity or a water pump.

As air passes through these boxes, actuators adjust the damper position, allowing different amounts of airflow into the area. Each VAV box adjusts to the needs of individual zones, meaning it can easily accommodate high demand in one area and low demand in another, keeping everyone comfortable. Additionally, if the damper is fully closed, the increased system pressure can slow down the AHU’s fans, thereby reducing energy consumption. Or use a bypass damper in the middle of the system, which may be triggered by increased pressure to open, relieving the system from additional ducting or external vents.

The benefits of variable air volume

The added control through VAV brings some benefits:

1. Precise temperature control
2. Reduce compressor wear
3. Reduce energy consumption
4. low noise
5. Waterproof and anti-corrosion

Xicheng control variable air volume products

The key components of these VAV systems are the actuators. These controllers are complex and fully programmable for application-specific functionality and any custom application you see fit. They also include integrated alerting, trending and scheduling to make powerful edge devices that can be controlled through BAS systems.

As buildings get smarter, so should your HVAC system. Having more control means more comfortable, lower cost and smarter buildings.