Adsorbent air cleaning: a new way to think about commercial ventilation

HVAC system

Do adsorbent air cleaning systems deliver on all that they claim? We test them to find out.

Over the past four decades, technology and engineering practices have made enormous strides in lowering the energy use of buildings. However, there is an area of building operations that remains a persistently high energy user: ventilation.

While ventilation serves to keep occupants at a comfortable temperature, it also needs to maintain the quality of the air. Conventional filters can remove things such as dust and pathogens from the air, but they miss certain gases such as carbon dioxide and volatile organic compounds (VOCs), including formaldehyde. 

To keep air clean from VOCs, the most common approach—known as “dilution”—is to remove contaminated air with an exhaust system and replace it with a lot of fresh air from outdoors. This naturally uses a lot of energy. 

But what if your building didn’t need to bring in outside air to maintain indoor air quality? Is there a different method to provide a safe indoor environment that could also drive energy savings?

The Technology

One proposed solution is adsorbent air cleaning. Adsorption is a concept as old as chemistry itself, and it has been applied for decades to technologies in fields such as industrial emissions control. In building ventilation, however, it's still an emerging technology—a potentially promising candidate for a more creative ventilation solution.

Adsorption is a process which removes toxic gases by passing air through a porous substance such as activated carbon (which is called the adsorbent medium). The adsorbent medium can be engineered to selectively remove some kinds of molecules while letting others pass through. In this case, the adsorbent medium traps CO2 and VOCs but lets the friendlier components of air through, like oxygen and nitrogen.

When applied to commercial ventilation, adsorbent air cleaners clean the air already in the building rather than bringing in large amounts of air to dilute contaminants. This approach can substantially reduce the amount of outside air required for ventilation, thereby cutting down on the associated heating and cooling energy loads.

In a recent study for a major Midwestern utility, our team studied the air-quality impacts of retrofitting an adsorbent air cleaning system into an existing office building. We'll be able to share full results in the coming months.

Learn More

Join us for a full review of this technology during a free educational webinar on Tuesday, June 22, 2021.

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