SARS-CoV-2, the virus that causes COVID-19 and its Delta and Omicron variants, can linger in the air for several hours, if not longer. It can also infect people at distances of up to 6 feet; in some “preventable circumstances,” such as in enclosed spaces with inadequate ventilation or air handling, these airborne particulates can float even farther. When the aerosols fall, landing on surfaces, they can live as long as several days. No wonder air purifiers, high efficiency particulate air (HEPA) filters, and other air purification/handling measures are on the minds of nearly every facility owner and manager!
COVID, Omicron & the Benefits of Air Purifiers
The benefits of using an air purifier, especially a HEPA air purifier system, are many, including that it:
- Creates cleaner, safer, healthier indoor environments
- Protects against the spread of infectious diseases caused by viruses or other pathogens
- Helps eliminate pathogens before they land and require removal from surfaces
- Saves cleaning labor and time.
In fact, in one study, using two HEPA air cleaners close to the airborne aerosol source reduced exposure to exhaled aerosols by up to 65%.
Choosing an Air Purifier System
With so many different air purifiers on the market, determining the most effective can be challenging, confusing, and time-consuming. To help determine which may be best suited for your facility, Servicon’s Innovation Council has done the research for you.
Below is information about the air purification and HEPA filtration systems we recommend, including how they work and their advantages depending on the available budget. While we also list potential challenges and considerations, we have found these to be among the best and safest options, especially compared to other relatively new air purification options on the market with unverified claims.
Ultraviolet Germicidal Irradiation
Ultraviolet Germicidal Irradiation (UVGI) is a disinfection method that uses short ultraviolet (UVC) wavelengths of 200-280 nanometers to kill or inactivate microorganisms and viruses in the air and on surfaces.
There are several advantages and benefits to UVGI, including that it:
- Is known technology used since the 1980s and approved by the CDC to combat the risk of tuberculosis (TB)
- Offers various installation options, including in-duct, upper-room (see below), or portable systems
- Allows minimal UVC penetration of human tissue
- Is sustainable and environmentally preferable, using no toxic chemicals
- Kills microorganisms other devices may not
- Uses minimal power
- Is easy to install
- Is the least expensive of Servicon’s recommended options.
While UVGI offers many positive attributes, it is not without its potential challenges, including that it:
- Can penetrate the outer surfaces of eyes and skin, so both should be shielded to prevent direct exposure
- Does not remove most allergens, dust, cigarette smoke, VOCs, gases, chemical fumes, and other contaminants
- Requires installation for every air handling unit
- Needs direct exposure to kill viruses; it loses effectiveness if blocked by soil, dust, bodily fluids, or other contaminants
- May have limited effectiveness on extremely fine aerosol particulate
- Can allow small pathogens (<2.5 micrometers) that cannot be controlled by bulk airflow to remain suspended for days or weeks.
Two Ways to UVGI
There are two types of UVGI air purification systems. With in-duct, the UVGI system is installed in HVAC units so that the UVC light disinfects the air as it cycles through the return ducts. Upper-air UVGI systems use wall/ceiling-mounted fixtures or modular units to create a disinfection zone focused above and away from people. Again, there are advantages and challenges worth considering, although often, choosing a system comes down to costs. In-duct UVGI is the more affordable of the two options.
In-duct UVGI
Besides the lower cost, the advantages of an in-duct UVGI air filtration system include that it:
- Can be customized to fit most air conditioning units
- Keeps coil, drain pan, and wetted surfaces free of microbial growth
- Supplements the existing HVAC system
- Disinfects moving air when placed downstream of the HVAC coils
- Eliminates filter replacement due to biohazards when installed in front of HVAC filters
- Requires relatively low power (120 V, 120–200 W each)
- Is easy to install.
Things to consider before installing an in-duct UVGI air purification system—besides ensuring it is compatible with the HVAC unit—include understanding the system:
- Needs higher powered or additional UV lamps to inactivate pathogens in a short time
- Calls for more frequent HEPA filter replacement
- Requires bulb replacement/HVAC servicing every two years.
Upper Room UVGI
The advantages of an upper-room UVGI system include that it:
- Disinfects air as it is circulated by air handling units, such as ceiling fans or natural air movement
- Disinfects the air closer to and above room occupants
- Supplements existing HVAC systems incorporating Minimum Efficiency Reporting Values (MERV) 13 filtration
- Uses the least power (120 V, ~60 W each) of recommended options
- Is easy to install
- Is less expensive than APC air purification systems (see below).
Considerations to take into account before installing an upper-room UVGI include that this type of system:
- Needs higher powered or additional UV lamps to inactivate pathogens in a short time
- Calls for more frequent HEPA filter replacement
- Requires bulb replacement/HVAC servicing every two years
- Must be compatible with HVAC unit
- Requires placement before and after the HVAC’s MERV 13 filter when UVGI is the only air filtration system used.
Active Particle Control (APC)
Active Particle Control (APC) is an air filtration technology developed by SecureAire that works primarily by local electrostatic field manipulation. This process continuously initiates millions of particle collisions to create particles large enough to be carried by air currents. Once the particles are large enough, APC uses an electric field to kill the pathogens by disturbing the balance between free radicals and antioxidants, a condition known as oxidative stress.
The advantages of APC air purification are that it:
- Optimizes ionization and polarization to charge and collect small particles, viruses, bacteria, VOCs, and gases
- Shows proven COVID-19 mitigation
- Reduced or inactivated particles and pathogens by 94.4% in a community hospital* Lowered or inactivated particles and pathogens 95% in academic medical center operating rooms*
- Resulted in a 95% kill rate of an anthrax biological warfare surrogate within three hours*
- Provides high filter efficiency
- Uses low power (120 V, 75 W each)
- Is sustainable and environmentally friendly, using no toxic chemicals.
Items to consider before installing an APC air purification system include its:
- Higher initial expense and ongoing maintenance costs.
- Large size of most modular units
- A newer technology with an unknown life span.
Omicron-COVID-19 Air Purification Options Near Me
Read more about these and other new air purification and HEPA filtration systems in Servicon’s Indoor Air Quality (IAQ) Options & Recommendations or contact a Servicon representative or call us at 310-204-5040.
* According to studies published in the American Journal of Infection Control
