Over the past year and a half, we’ve all become more conscious of the air we breathe. Many of us have found comfort gathering outdoors, breathing in the fresh air. As temperatures drop, however, most people will have little choice but to spend most of their time indoors once more. Spending long periods inside can cause illness and discomfort if the indoor air becomes stale. Fortunately, there are many ways to improve indoor air quality (IAQ), namely through different methods of air purification. The goal of any air purification system is to eliminate and sanitize airborne pollutants and toxins that can lead to negative health outcomes, including dust, fungal spores, allergens, viruses, and more. While every facility benefits from air purification, on the whole, different types of purification may be better suited for different situations. With that in mind, let’s explore the four primary types of air purification systems, how they work, and their unique pros and cons.

High-Efficiency Particulate Absorbing (HEPA) Filtration

Perhaps the most widely-known air purification method, HEPA filtration, is also deemed the most effective means for removing harmful materials from the air. Indeed, HEPA filters effectively trap approximately 99.97% (or more) of airborne particles 0.3 microns in size or larger -- this includes a wide range of viruses, bacteria, mold spores, and other microscopic materials. The zig-zag shape and fibrous material of a HEPA filter allows for easy and ongoing airflow while providing ample surface area and texture to ensnare countless particles. Of course, filters will need to be changed at certain intervals as they become saturated with pollutants (usually every 2-4 years or so).

Aside from needing to replace filters every so often, the only other downside to HEPA filtration is that this method doesn’t get rid of odors, gases, or certain chemicals. The good news is that other air purification methods can be combined with HEPA filtration to pump the brakes on these harmful substances, too -- this leads us to the next type: activated carbon filtration.

Activated Carbon Filtration

Developed over a century ago, activated carbon is a highly porous and absorptive material that can capture a whole host of harmful substances in a given room (and in water), such as gases, chemical emissions, volatile organic compounds (VOCs), odious odors, and more. Activated carbon filters are able to achieve these things thanks to their tiny pores and large surface areas. Substances like formaldehyde, which can linger in furniture, carpeting, and other porous surfaces, are no match for high-quality activated carbon filtration.

It’s worth noting that activated carbon can’t solve all indoor air quality problems on its own, however. While these filters are great at keeping a number of harmful substances at bay, they’re less effective at eliminating standard allergens and other airborne particles. As such, activated carbon filters are best when combined with HEPA purification (as mentioned above) -- when working in concert, these two powerful methods help ensure the cleanest air possible.

Negative Ion Air Filtration

Small particles may be difficult to see, but they still have physical and chemical properties. If you recall anything from entry-level chemistry, you’ll remember that particles with a negative or positive charge are called ions. Opposites attract, so negatively charged particles will cling to positive charges and vice versa. Ionization is the technical term for what happens when particles gain or lose electrons and therefore become negatively or positively charged. This fundamental law of electromagnetism lies at the heart of negative ion air filtration. Simply put, pollen, dust, and many other airborne particles will stick to negative ions due to electromagnetic forces. So, negative ion filtration helps remove such particles from the air by forcing them to cling to surfaces inside a given room, such as walls, windows, etc.

As effective as ionization can be at diverting airborne particles, this method doesn’t purify indoor air to the same degree as the two other methods mentioned above. This is because negative ion air purification doesn’t actually sanitize the air but rather temporarily pushes contaminants aside. If surfaces are not subsequently and regularly cleaned and disinfected, these particles can break free and enter the air once more. Still, ionization can be a powerful tool in your air purification arsenal. An electrostatic air filter, for instance, uses the principles of ionization and can be used in conjunction with other air filtration methods (i.e., HEPA, activated carbon) to great effect.

Ultraviolet Light Disinfection

Since the beginning of the COVID-19 pandemic, there has been much discussion regarding ultraviolet light and its potential to kill viruses (among other things). After all, “sunlight is the best disinfectant,” as they say. As it turns out, there is some truth to this saying, especially when it comes to UV-C radiation in particular. UV-C rays are the most energetic rays on the UV spectrum. Not only can these rays seriously burn one’s skin and eyes -- they can also destroy microorganisms like bacteria and viruses by irreparably damaging their DNA. UV-C air purification systems employ powerful lamps that contaminants have no choice but to pass through and fall apart. The best UV disinfection and air purification systems also greatly reduce ozone inside a building. Of course, people should not get near high-powered UV lamps when active, as they can harm the skin and increase the risk of skin cancer.

While UV-C light is highly effective when it comes to killing harmful microorganisms, it doesn’t eliminate airborne particles altogether. In fact, some microorganisms can avoid the killing blow of UV light by hiding behind other particulates. As such, the best use of UV technology in this regard involves combining it with HEPA and activated carbon filtration as the initial stages. Once the air has been filtered via these means, UV light can do what it does best and kill the most pernicious microorganisms caught in the system. UV-C technology has become a staple in healthcare settings in facilitating air disinfection for coronavirus.

Our health and well-being are closely tied to the air we breathe on a regular basis. In this way, the four air purification methods described above are important parts of building maintenance, and they’re often most effective when combined. At The Budd Group, we’re committed to increasing the safety protocols and health outcomes for all our clients and their people. Let us help you keep your facility and its air clean. To learn more about our services and values, give us a call today at 800-221-8158!