Skip to the main content.

3 min read

What Is a UFAD System?

What Is a UFAD System?

Addressing the heating and cooling needs of a building with underfloor air distribution isn’t new. In fact, underfloor air distribution (UFAD) played a prominent role in Thomas Jefferson’s Monticello estate.

If UFAD is good enough for a Founding Father, it’s certainly good enough to explore further.

Whether a new project is on the horizon or just some long-overdue renovation work, it’s never a bad idea to look at an underfloor air distribution system in greater detail.

Deconstructing the Average UFAD System

As mentioned before, UFAD systems aren’t new, but technology has improved the system in ways that focus on efficiency, energy-saving, and more.

Modern office buildings, schools, and other large-format buildings call for paying closer attention to air conditioning, especially in areas where the air temperature can increase dramatically and linger at high temps for long periods.

How Do UFAD Systems Work?

Within a UFAD system, it all starts with the activity underneath the main floor. This is where the plenum is hosted, a key part of air distribution systems.

The return air is sent back in at the ceiling to remove warm air faster, which is ideal when the office building needs to be kept cool.

By pulling the air upward above the height of most people, air quality is drastically improved.

This system design is focused on making the UFAD way more efficient than an overhead system, which is often bulky and protrudes out into working spaces.

For the UFAD system to work, the air is delivered from the ducts connected to the underfloor plenum. This is just one way to do it; a pressurized plenum setup is another way to handle air flow.

The floor system means that air is felt best at the floor level and continues upward, and raised access floors allow for ongoing maintenance or even upgrades as needed.

This design is advantageous for office buildings and is very effective at keeping specific areas of the building comfortable with improved air quality.

Advantages of UFAD Systems

Why are UFAD HVAC systems growing in popularity? The under floor ventilation aspect is part of the advantage, but it goes much deeper than just this component.

Here are a few reasons why underfloor air distribution systems have taken off so well:

  • Space-saving. Since the system uses underfloor plenums rather than taking up visible space, UFAD is great for getting conditioned air right to all of the key occupied zones.
  • An underfloor system gives multiple points of delivery, from supply outlets to partitions. This is far more flexibility than what’s available with conventional overhead systems.
  • Underfloor air distribution systems can be bundled right next to cable, data, audio, and other key electronic/technical services needed in an office building, making it easier to maintain.
  • Environmentally friendly. Because of the improved energy efficiency, implementing UFAD can often lead to LEED credits, something that is desirable for many companies.

The space-saving, energy-saving, and flexibility of UFAD is unmatched when compared to an overhead system.

Floor diffusers simply allow for better regulation of air temperature.

Drawbacks to UFAD

No system is perfect, and there are a few drawbacks to UFAD systems that people should know about before they begin to invest in the setup.

Here are those downsides:

  • Higher upfront cost compared to overhead systems. While this isn’t a given, it is a possibility that can throw off a budget without careful planning.
  • Zone control. Not every building lends itself well to UFAD; buildings that have lots of private offices could end up having to put in workarounds in order to enjoy the air conditioning they need.
  • Retrofitting. UFAD lends itself better to new projects than extensive conversions. The cost to replace everything with a UFAD setup may exceed the renovation budget completely.

As you can see, these aren’t hard dealbreakers that should keep anyone away from exploring the merits of UFAD.

All of these concerns can be worked around with enough time and planning. The benefits truly do outweigh the drawbacks.

Getting Clear About UFAD Best Practices

It is important while examining the advantages and drawbacks of UFAD systems to also think about the overall life-cycle for the HVAC system.

Indeed, any system is going to have maintenance requirements. It is also possible for the system to break down in ways that require replacing parts.

For example, underfloor plenums are reliable, but leaks have been known to happen. Instead of dismissing UFAD, consider that parts of all kinds do indeed wear out.

This means that there should be a maintenance plan in place from the beginning.

Implementing UFAD Wisely

Without implementation, UFAD HVAC systems are just a good idea on paper.

Bringing it to life will involve planning, ordering the parts, finding a qualified team to install, monitoring the project, having it managed effectively, and examining the final results for any adjustments.

The reason why it’s important to take the time to plan is simple: every building is going to be a little different.

While multifamily is definitely on the rise, not every multifamily set of units will benefit from UFAD without adjustments.

This guide, like so many, should be seen as an introduction to the benefits and wide use cases.

The specifics get trickier because one guide cannot cover every single combination out there when it comes to location, climate, building type, and even the technical/electronic services already on site.

Don’t Fly Solo: Trust AirFixture With Your UFAD Needs!

As mentioned previously, the benefits of UFAD systems are tough to beat.

However, if you’ve only dealt with traditional overhead cooling systems, working with a new concept can feel overwhelming.

For example, did you know that not all underfloor diffusers and underfloor ducts are the same? The airflow ratings can be quite different, and the right one depends on the application.

Let the UFAD specialists at AirFixture know the unique aspects of your project.

We'll not only make recommendations on the materials, but will also give key advice that will save time, prevent project overruns, and ultimately save you money.

Contact us today to get started.

Photo by Arlington Research

Featured Photo by Adolfo Félix

Underfloor vs Overhead Air Distribution

Underfloor vs Overhead Air Distribution

Until the 1970s, there was one primary method to deliver ventilation and conditioned air into commercial spaces. The traditional HVAC system, which...

Read More
Underfloor Air Distribution Temperature Control

Underfloor Air Distribution Temperature Control


Read More

What are the Costs of Implementing an Underfloor Air Distribution System?

Underfloor air distribution (UFAD) continues to gain popularity among building and facility owners due to the range of benefits it offers versus a...

Read More