What Is the Difference Between a TFA and an AHU?

Every home and building in Texas needs access to cooling. Summers are warm everywhere in Texas, and without cooling, things can be miserable. The weather can even be downright dangerous. So it’s important to understand your options and choose the right cooling system to match your needs.

One choice before you is the specific type of unit you choose. TFAs and AHUs are the most common types of air conditioners, and they offer notable differences to your daily experience. Let’s go over these units together so that you can understand what separates them and why one might be a superior option for your home or building.

Basics of a TFA

To begin with, TFA stands for “treated fresh air.” A TFA unit is one that pulls all of its intake air from outside of the building. The air is then filtered and treated, but none of the source air is already in the building at the beginning of the treatment cycle. This is the defining characteristic of a TFA.

Because the TFA unit adds air to the indoor space from outdoors, it has to have an exhaust system. Without exhaust, the air pressure inside the building would steadily increase. A little bit of pressure increase is fine, but over time, it could become problematic.

This fact adds a complication to the overall system that handles your air. That can make TFA systems more expensive and a little more complicated for maintenance and repair. For that price, TFA units gain the ability to deliberately pressurize air inside of a building. This has many commercial applications. It’s great for keeping bugs and contaminants out even when people open the door and walk in. For a home, it’s less important.

When it comes to cooling, TFAs need more energy. A traditional AHU treats indoor air, so it pulls already cooled air into the system for further cooling. When the TFA pulls air from outdoors, the starting temperature of the treated air is much higher — particularly in the peak of summer. That higher temperature air requires more energy for the system to cool it down to a comfortable level.

Traditional Air Handling Units (AHUs)

An AHU pulls all of its air from the interior space. Ultimately, this leads to a perpetual recycling of enclosed air. The AHU still uses a filter, and it still cools the air as needed to maintain thermostat temperatures. Some AHUs also heat air, but the main takeaway is that AHUs get their air from interior intake vents. When discussing AHUs and TFAs, neither gets air from a mix of indoor or outdoor sources. For these two types of units, it’s all or nothing from the interior or exterior of the building.

An AHU does not change the interior air pressure. For commercial spaces that need increased air pressure, AHUs are less valuable, as they need additional resources to create that pressure. When air pressure doesn’t matter, AHUs are great for cooling because they are more energy efficient.

That said, there is a sense of general value for including fresh outdoor air in a system. AHUs recycle air perpetually, which can lead to stale air. It’s filtered, so the air doesn’t become polluted, but it can lack fresh air qualities that are pleasant and even mood boosting. AHU systems can compensate for this with open windows or cracked doors. Doing this allows the home to exchange air every now and then, but keep in mind how this impacts the system. Leaving doors or windows open for an extended period of time will impact the cooling efficiency and effectiveness of your HVAC system. That said, it’s perfectly reasonable to get some fresh air now and then.

In the big picture, TFAs and AHUs are both viable, effective cooling devices for traditional HVAC systems. While they have different pros and cons, either system can keep you comfortable throughout the year, and both effectively filter the air for the sake of air quality. If pumping fresh air and pressurizing a building hold value, TFAs are unquestionably superior. If energy efficiency is the goal, AHUs are a clear winner.

Whatever cooling system you ultimately choose, what matters most is that you can have it installed and maintained at a professional level. For that, Metro Express Service is here with expert TFA and AHU AC unit service in Arlington and the surrounding areas. Contact us today. We’ll help you explore your options so you can pick the best unit for your home or building. We can professionally install your new system, and we can schedule regular maintenance to keep it in great shape.


Randy Murphy

Randy Murphy has been building his knowledge of the air conditioning and heating business for several years now. He first started applying his knowledge while working for his father’s HVAC company. Later, in 1987, Randy started his own business: Metro Express Service. He has been a top 10 Trane & Amana dealer for over eight years. When it comes to heating and cooling, Randy knows the business better than anyone.
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