recent posts



What is an air terminal unit? Why is it used?

November 8, 2021

What You Need to Know About Air Terminal Units 

If you’ve ever walked into a cool building after being outside in the heat, you were probably thankful for that cold, refreshing air. But how does that nice, cool air get throughout the whole building? If it’s a larger building or commercial space, then an air terminal unit is probably responsible for dispersing that cool air throughout the space. 

But, what is an air terminal unit? 

An air terminal unit is “a device that is used to regulate the volume of conditioned primary air from the central air handler to the occupied space.” Basically, this is what controls the amount of cool air being blown into a room. 

How does it work? 

Check out this video that explains in detail how these units work!  

When cool air flows from the central air handler and reaches the air terminal unit, an air flow sensor measures the difference between the total and static pressure. Then a terminal controller takes that data and uses it to determine the rate of the air flow through the inlet. The controller then adjusts the damper, which allows more or less air through the unit depending on what is needed to meet performance requirements and maintain optimal comfort in the space.  

Why is air flow important? 

By controlling the volume of air distributed into a space, the terminal unit allows the desired temperature to remain constant. Yes, this is an important factor in keeping people comfortable, but air flow also contributes to the health of people in a confined space. According to the CDC, increasing air flow in a building “can reduce the risk of exposure to the [COVID-19] virus and reduce the spread of disease.” 

What are the different kinds of air terminal units? 

Let’s look at three of the most common types of air terminal units 

// about the author
Allison Hamilton

Allison Hamilton

Allison Hamilton is the Video & Marketing Coordinator for the Hoffman Family of Companies. She enjoys learning about the HVAC industry and meeting new people along the way.

// share this post