Indoor air pollution is a serious health risk and often worse than outdoor pollution because of the elevated concentration levels. An air scrubber is an air purification system that combats poor indoor air quality by removing pollutants and contaminants from the air. Let’s explore how air scrubbers clean air for easier breathing, reduced allergy and asthma symptoms and a healthier environment overall.
Air Scrubbers Have a Dedicated Fan
Manufacturers use the term air scrubber broadly. That means you’ll find exceptions, but generally, an air scrubber is a standalone air purifier with a motor and fan. That fan draws air into the system and forces it through a series of filtration stages. That allows air scrubbers to be used as portable units for commercial applications and residential mold remediation. It also makes them suitable for homes with both ducted and ductless HVAC systems.
How much air an air scrubber moves is an important factor. Manufacturers will indicate this airflow in cubic feet per minute (CFM). CFM reflects not only the power of the fan motor but the resistance created by the filter media. When choosing an air scrubber, CFM alone is not enough information. You need to know the treatment volume and air changes per hour (ACH). Treatment volume reflects the coverage the air scrubber provides. If you have a 2,500-square-foot home, you want an air scrubber with a treatment volume of 2,500 sq. ft.
ACH indicates how many times an air scrubber filters the treatment volume an hour. An air scrubber rated for 4 ACH will filter the treatment volume four times an hour. The Centers for Disease Control and Prevention (CDC) advises 4 ACH as a baseline. Many of the air scrubbers on the market provide at least 5 ACH. Households that have members with asthma or bad allergies may want to consider 6 ACH or higher.
You may also come across clean air delivery rate (CADR). CADR is generally more useful for portable air purifiers, but some air scrubber brands provide it as well. It indicates how much clean air the unit provides per minute. If sizing an air scrubber by CADR, experts recommend a two-thirds rule. For our example home, you would want a CADR between 1600 and 1700.
Air Scrubbers Are Compatible With Both Ducted and Ductless HVAC
For homes with central HVAC, it’s common to install an air scrubber in the ductwork. The ductwork is the return side of the system. This is important because the CFM of the air scrubber doesn’t interfere with the static air pressure of the HVAC system. It also allows the air scrubber to deliver the air more evenly throughout the home. The air scrubber uses the same ducts and vents your HVAC system does.
For homes with ductless HVAC, you’ll typically need a higher CFM in order to provide filtered air throughout the home. You also have several configuration options to choose from. There are wall- and ceiling-mounted units available. You can also install an air scrubber in the attic along with a dedicated supply duct and centrally located return duct.
Air Scrubbers Perform Mechanical Filtration
Most air scrubbers remove particulate matter from the air through mechanical filtration. The air scrubber fan forces air through physical media that traps the particles. Most systems will have two layers of mechanical filtration: prefiltration and primary filtration. The prefilter is usually an inexpensive filter that you can swap out regularly. Its job is to trap any really big particles in order to preserve the more expensive primary filter and protect the air scrubber components. For the primary filter, minimum efficiency reporting value (MERV) and high-efficiency particulate air (HEPA) are important concepts.
MERV indicates a filter’s ability to trap particles between 0.3 and 10.0 microns. The higher the MERV rating, the greater the efficiency of the filter. Central HVAC systems require an air filter at the supply vent. Most modern systems support between MERV 8 and 13. A MERV 13 filter will trap 90% or more of all standard household allergens, such as dust, pet dander and pollen. The filters found in air scrubbers are generally much thicker than those used for HVAC for greater capacity.
Many air scrubbers use a HEPA filter, which is a type of pleated filter. Standard air filters are excellent at trapping large particulate matter but not fine and ultra-fine particulate matter. These are the particles we associate with smog and automobile exhaust. HEPA filters have a MERV rating of 16 or higher and trap almost 100% of all large, fine and ultra-fine particles. Although not common for residential use, there are also medical-grade HEPA filters. Some air scrubbers support these to provide even more comprehensive protection against ultra-fine particles.
Air Scrubbers Perform Absorptive Filtration
Most air purifiers with mechanical filtration will provide absorptive filtration as well. Air scrubber brands typically achieve this with a substance known as activated charcoal or activated carbon. Activated charcoal is a processed form of carbon. The process creates many tiny pores that greatly increase the surface area of the carbon. These pores allow the carbon to absorb gases and chemicals and have a large capacity. Activated charcoal absorbs unpleasant odors to make a home smell fresher. It also absorbs volatile organic compounds (VOCs).
Some Air Scrubbers Use Ionization Instead
Some air scrubbers use ionization instead of mechanical and absorptive filtration. These systems have ion generators, and those ions attach themselves to pollutants to neutralize them. Some ion air scrubbers have containment areas that hold these bound particles. All ion generators also trap particles against surfaces, such as your walls and curtains. There are also some air scrubbers that are similar in concept but use hydrogen peroxide instead of ions. If you choose an ion air scrubber, the Environmental Protection Agency (EPA) warns to watch for units that produce ozone. Ozone is an irritant and particularly bothersome for those with respiratory conditions.
Some Air Scrubbers Perform Ultraviolet Germicidal Irradiation
Some air scrubbers with mechanical and absorptive filtration will have an ultraviolet (UV) lamp as well. The lamp gives off germicidal light and provides what is known as ultraviolet germicidal irradiation (UVGI). This light neutralizes bacteria, viruses, mold spores, fungal spores and dust mite eggs.
One concern is that UVGI benefits from slower moving air while an air scrubber benefits from high airflow. This is why some experts recommend an air scrubber without UVGI and instead installing a UV lamp in your ducts.
Local Indoor Air Quality Experts in Rockwall
Bacon Plumbing Heating Air Electric is a family-owned and -operated business that’s served Rockwall and the entire Dallas-Fort Worth Metroplex since 2011. We have sheet metal fabricators and install and repair ducts. Our indoor air quality team cleans ducts and specializes in air purifiers, UV lights, dehumidifiers and humidifiers. Our HVAC technicians specialize in smart thermostats, gas and electric furnaces, heat pumps, air conditioners and ductless mini-splits. We have plumbers that pipe and repipe water, sewer and gas lines. They unclog drains and fix leaks. Our plumbers hook up appliances and install toilets, water heaters, garbage disposals, sump pumps, water filters and water softeners. We also have electricians who perform inspections, electrical repairs and panel upgrades. Our team installs indoor and outdoor lighting, generators, EV charging stations, outlets, switches, fans and much more. Contact us today with any questions or to schedule a consultation or service appointment.
