Published December 25, 2022

What Is Air Balancing? (Why It’s Required & Its Importance)

air balancing in commercial office building

“What is that?” The most common thought or response from someone hearing they need  air balancing for the first time.

If you have no idea what air balancing is, you are not alone. Almost everyone benefits from it yet no one even knows this service exists.

Why’s that? For one, it’s only required to be performed on commercial buildings and is typically the last process in any new construction or renovation.

The contractor or owner of the building is usually the one responsible for finding an independent air balancing contractor for their project or building and no one other than these individuals learns of this process.

So if we had to guess, you are either a building owner, business owner; or a contractor responsible for the project and you were just told you need an air balance performed with a certified report issued by the balancer.

As a full-service air balancing contractor located in Southern California, we are very accustomed to our customers not fully knowing what an air balance even is and that’s why we’ve created this article.

So let’s begin with the main question…

What Is Air Balancing?

Air balancing is the combined process of testing, adjusting, balancing, and inspecting if air-moving equipment is installed to code. 

Now, this is the short answer to what air balancing essentially is, however; let’s break it down into the tasks mentioned above.


Testing is the first step in any air balance project. The airflow leaving an air-moving device (HVAC Unit, Exhaust Fan, Restaurant Hood, etc.) is measured to determine the total airflow it is producing.

This lets the air balancer know if the equipment is producing what it was engineered to. 

In the testing phase, each airflow register is also measured to determine if the correct amount of airflow is entering each room or zone.

With this information gathered during the testing phase, the air balancer proceeds to the next step.


When airflows measured don’t match the required engineered amounts they need to, either the equipment, specific register location, or both need to be adjusted until they do, hence the term “adjusting.”

If the equipment is under or overproducing air, the balancer is to adjust the equipment to either lower or increase its airflow.

If the airflow at specific registers does not meet the CFM (cubic feet per minute) requirements provided by the mechanical engineer, the balancer needs to adjust each one using the airflow dampers installed at each register until they produce the correct CFMs.

The main goal of the adjusting phase is to achieve a proper balance in the building.


Balancing is a literal meaning and is more of the end goal. It usually refers to a balance of building pressure, an equal rate at which a building cools down or heats up when the HVAC equipment is running, and introducing the correct amount of outside air into the building.

The definition of balancing may vary slightly depending on the specific type of air balance service being performed, we will explain more about each of these topics further in this article.


During an air balance procedure, part of an air balancer’s job is to also inspect the project and equipment and make notes of any code violations or something that was missed during the installation. 

This does not mean the air balancer is simply another inspector and is out to get you. Many TAB (test, adjust, and balance) firms, including ours, are here to help and protect you. 

Our priority is to bring these code violations to your attention to protect you as a contractor from any liabilities; and as a business owner from improperly installed/functioning equipment.

We don’t view ourselves as code inspectors, however, we do look out for them for your safety.

Air Balance Reports

The final step, which has not been mentioned yet, is compiling all the initial and final testing results of the air balance procedure into a report known as an air balance report.

The report is created in an industry-standard layout that is simple for city inspectors and engineers to understand.

Air balance reports are required to be provided during city inspections and after new installations.

So now that you have a solid understanding of what air balancing is and why it is important, let’s discuss why it is required.

Why Air Balancing Is Required

Air balancing is required for commercial buildings to ensure mechanical air-moving devices installed in them are functioning within their engineered specifications, are installed correctly, and are operating at their maximum efficiency. An air balance also ensures the air quality inside the commercial building is safe.

This is a short broad answer, however, let’s break down why air balancing is required by the different forms of air balancing services.

Restaurant Air Balancing

Restaurant air balancing is a requirement by the health department to not only confirm that the equipment is running smoothly and installed correctly, but to also verify the building’s pressure is equal relative to the outside. 

Every restaurant in California and the majority of the United States has an exhaust hood for very obvious reasons.

The Exhaust Hood

The exhaust hood is designed to extract the smoke and heat outside, and it does it well, however; it ironically does more bad than good.

The exhaust hood removes so much air from the building that it can create negative pressures within a building.

This negative pressure can cause issues such as awful sewage smells, hard-to-open exterior doors, uncontrollable dust and grime buildup, excessively hot temperatures, unhealthy kitchens, and an overall poor dining experience for customers. 

To counteract the negative pressures the exhaust hood creates, a device called a make-up air (MAU) is required to be installed along with it.

The Make-Up Air Device (MAU)

The make-up air simply does the exact opposite of the exhaust hood, it brings outside air into the kitchen instead of out. The MAU is designed to bring in the same amount of CFM (measurement of air) into the building that the exhaust fan is extracting.

For example, if the Exhaust fan is exhausting 3000 CFM, then the MAU should be bringing in 3000 CFM to counteract the negative pressure created by the exhaust fan, (unless requested otherwise by a mechanical engineer).

The Make-up air can also double as a way to create safe air quality in the kitchen, however, the HVAC system usually has this responsibility, which, brings us to our next topic…

HVAC Air Balancing

As an air balancing company, it is safe to say that HVAC air balancing is the majority of what a TAB specialist does.

HVAC air balancing, in the shortest explanation possible, is the process of testing and adjusting the equipment, the economizer. and each supply/return register to produce the correct amount of airflow they were engineered to produce.

This procedure resolves many issues within a commercial building but there are three main ones that are the most vital.

The 3 Main Concerns HVAC Air Balancing Resolves In A Commercial Building 

The AC test and balance process addresses the 3 main concerns within a commercial building.

One – The equipment is not overworking itself ensuring that it is running smoothly and efficiently.

Two –  There will be no rooms that get hot or cold faster or slower than other rooms. When the temperature satisfies all rooms throughout the building will be the same temperature.

Three –  There is safe indoor air quality or breathing air for all people within the commercial building. This is done by the fresh air economizer installed on the HVAC equipment.

The Economizer & The Importance Of Indoor Air Quality In The Workspace

All commercial HVAC equipment is required to be installed with an economizer which is designed to introduce outside air into the building along with the conditioned air to control carbon dioxide (CO2) levels from rising.

This rise in CO2 levels is from the occupancy in the building breathing the same air within a building while no new air is introduced. 

These levels of CO2 caused in a workspace may not be immediately deadly, however, they can cause issues such as a lack of focus, drowsiness, and if exposed to these conditions over years, may even cause deadly health defects. 

While the main concern for safe breathing air is focused on the people within the building, having healthy indoor air quality in the workspace may even benefit a company’s productivity rate, workflow efficiency, and even revenue in ways greater than one may realize. 

The lack of focus in the office may be deeper than simply unmotivated employees, it may be due to the lack of fresh clean air!

But, having an economizer alone won’t create a healthy workspace, it first needs to be commissioned and adjusted to meet the CFM requirements to achieve the correct amount of fresh air to occupancy ratio, and… this can only be achieved if both, the AC equipment and each supply/return diffuser are balanced as well.

The reason the entire system needs to be completely adjusted and balanced to achieve healthy indoor air quality is that most commercial buildings have separate rooms with shut doors.

In an office, for example, there usually are many different office rooms and many of these rooms have shut doors. So the only way for this outside air to enter each room is through the supply registers installed inside each office room, and; a room can only receive the correct amount of outside air if the air entering the room was balanced to the correct CFMs in the first place. 

There is a lot that goes into the HVAC air balancing procedure, and all these reasons are why it is incredibly important and even required by law to be performed on all commercial buildings.

How Air Balancing Can Lower Electric Bills & Raise Equipment Life Spans

Now that we have a good grasp on the different forms of air balancing and why they are required, let’s look into two amazing benefits the air balance process can provide.

Energy Efficiency

The first benefit is maximum system energy efficiency.

According to the Annual Energy Outlook 2022, in the U.S. about 16% of the residential sector’s total electrical usage goes to running HVAC systems.

For the commercial sector, it is about 12%.

This is proof that the HVAC system is the biggest electrical factor in the majority of residential and commercial buildings.

To add to this, most HVAC systems waste even more electricity when they aren’t running to their maximum efficiency.

What may cause a system to not be running efficiently may be due to improper installation, improperly sized ductwork, faulty components, low refrigerant charge, and not being properly air balanced.

The very sad truth is that many systems have all of these problems…

Performing an air balance on a system helps to prevent most of these from existing.

This issue alone can be a reason why air balancing is incredibly important, wouldn’t you want your system to run at its max energy efficiency?

System Longevity

The average lifespan of most HVAC systems is around 15 years.

Every one of the problems listed above can drastically reduce this lifespan.

We have seen major components go bad 1 year after new installations. And situations like this result from very poor installation errors or mistakes.

An air balance helps confirm that systems are installed correctly, running smoothly, and will last to or close to their maximum life expectancy.

Can You Perform Your Own Air Balancing?

The short answer to whether you can perform your own air balancing is no.

Only a certified and licensed D-62 air balancing contractor can perform commercial air balancing and provide air balance reports for city inspections. 

This contractor must be independent or unaffiliated with the project being tested.

The air balance company cannot be the mechanical contractor, sub-contractor, business owner, or building owner involved in the project needing testing.

Air Balancing Conclusion

Air balancing is a combined process of testing, adjusting, balancing, and inspecting commercial air-moving devices.

Following the completion of an air balance, a report is compiled to provide to the city and keep for personal records.

It is required to ensure commercial equipment is installed correctly, is operating efficiently, and was installed according to mechanical code.

Testing and balancing is incredibly important and is worth the cost due to the many benefits it provides short term and long term.

The balancing process ensures systems will operate to their fullest life expectancy and will run at lower energy levels.

The only person that can provide air balance reports is licensed air balancing contractors.

If you have any questions regarding air balancing feel free to message us, and if you air in need of an air balance schedule with us today!