Best HVAC System for Mass Timber Construction

Mass Timber Construction

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.

underfloor air distribution systems

Photo by Arlington Research

According to a recent report from the United Nations, the global population could rise up to 9.7 billion people by 2050, requiring the combined resources of over three Earths combined. 

This means that sustainability is more important than ever. Thankfully, sustainability can be achieved by looking into mass timber construction

Making a case for mass timber buildings isn’t difficult; wood is a renewable resource, while concrete, steel, and other manufactured items are not. 

Refining metal has an apparent environmental footprint that can’t be ignored, and while wood isn’t emissions-free, timber is naturally designed to trap carbon. 

Once the decision to pursue mass timber construction is made, what’s next? Well, it’s important to build circulation systems within mass timber structures

Understanding Mass Timber Construction

So, what is mass timber construction? Simply put, it’s building structures based on a mass application of wood panels bonded together for reinforced strength and structural integrity

Mass timber architecture is slowly growing in adoption; wood structural integrity is a hotly debated topic. 

This makes sense: concrete and steel have been the primary building materials for a long time, with mass timber design still gaining traction

Building codes are concerned with structural integrity, something addressed heavily with current heavy timber processes as well as within concrete and steel

Making Mass Timber Framing Safe 

The 2021 international building code, like so many other building regulatory frameworks, is focused on ensuring that buildings are as safe as possible. 

This isn’t just safety in the short term, but long-term structural stability. 

One of the reasons mass timber buildings have been slow to take off is conflicting policies. While innovations in the field occur all the time, building codes don’t keep up with technology. 

Mass timber projects have to show that they are just as safe as they would be if made from more conventional materials. The load-bearing capabilities have to be equivalent as well. 

How is this challenge met? 

It’s all about the timber construction materials, namely, nail laminated timber (NLT) and cross-laminated timber (CLT). When used jointly in projects, NLT and CLT work together to produce safe buildings that can pass fire tests

Does the 2021 International Building Code Address Mass Timber?

Building codes change, though usually not at the rate that developers are looking for. Clarity around mass timber buildings is necessary. 

The update to the IBC is great news for mass timber projects, as mass timber buildings can go up to 18 stories. 

Sure, that doesn’t allow for huge skyscrapers, but it does give rise to interesting projects. 

As mentioned before, multifamily housing truly is one of the most pressing needs across North America. 

The focus on building safety, building integrity, and fulfilling the demand for new construction can be met through cross-laminated timber (CLT)

The strength of this material comes from how the wood is laid out: large laminations of lumber laid perpendicular to each other. 

This natural material gets help through the modern application of heat-resistant adhesives and even a little concrete. 

The blending of materials with timber being the star is what makes the project mass timber; there is still room for supporting materials to be used in the construction process. 

The Difficulties of HVAC Within Mass Timber Projects

One of the most promising applications for mass timber structures is multifamily. The need for multifamily is felt across the United States and all of North America

The modern high rise isn’t a great fit in every area, which is why a tall wood building holds much more promise than meets the eye. 

But what about the HVAC systems? As you might imagine, there are some challenges with implementing a quality HVAC system that can take care of the heating and cooling needs of the building. 

The goal is to always aim for consistency, silence, and durability. 

The Rise of Underfloor Air Distribution Systems

Typically, when people think about air circulation, they’re thinking about the traditional way: down from the ceiling through a maze of vents. 

While this method is traditional, it isn’t the best way to go for multiple reasons: 

  • Lower ceiling heights make it difficult to implement traditional systems.
  • Higher energy usage is bad for the environment and your wallet.
  • Higher noise levels, which is the last thing anyone wants in a brand new apartment building.
  • Rushed installation of traditional systems can leave spots vulnerable to condensation, something to be avoided in a timber building.

The traditional way just isn’t the best way, for all of the reasons above. In addition, as these systems age (and all systems age), these problems become more and more pronounced. 

Maintaining a traditional ceiling-mounted system takes time and resources that are better spent elsewhere.

Expand Your Horizons

Many great concepts could truly gain serious momentum if converted to a mass timber design

Unfortunately, it can be difficult to even imagine a timber building when it’s so commonplace to think in terms of brick, concrete, and steel. 

Sometimes what needs to happen is a full reworking of the concept or just a push to embrace making mass timber manufacturers the star of the show. 

With so much money riding on the success of a new project, it can be hard to embrace emerging methodologies. 

The best advice? Tall mass timber concepts are possible, and they can change the way that we think about buildings in general. 

Can you imagine an apartment building with wood as the star of the show? 

The Underlying Systems Are King: Trust AirFixture With Yours!

While the exterior of the building will gain most of the attention, the truth is that the underlying systems are the real heroes of the day. 

AirFixture helps companies of all sizes navigate HVAC system decisions, especially when underfloor air distribution is concerned. 

Looking for the best system implementation? Let us help; we love answering questions just like these.