Wipes: The traditional sanitation practice of wiping down surfaces, spraying or fogging generates physical waste, introduces potentially troublesome chemicals to an environment and requires paid labor to implement. The cost of utilizing Krypton disinfection lighting is often 50-100 times cheaper than those alternatives when factoring in labor and materials costs and is not subject to human error and missing spots. Attempting to clean while spaces are occupied is also disruptive and often impossible. In contrast, Krypton lighting provides safe autonomous, and continuous disinfection while spaces are occupied, without the use of water, bleach, chemicals, rags, paper towels, mercury, hydrogen peroxide, cold plasma, or ozone.
Ventilation: A popular alternative to reduce the risk of indoor airborne exposure has been to utilize HVAC systems to bring in fresh air to dilute the potential viral load. A significant challenge with this strategy is that if the ambient temperatures outside are around comfortable room temperature, the HVAC systems have largely been programmed not to run, which would result in no fresh air. On the other hand, when the outside temperatures are not close to room temperature, just venting out all of the conditioned air outside turns out to be about 9.5 times the cost of Upper Room or Whole Room Far UV solutions.
HEPA Filters: A HEPA (High-Efficiency Particulate Air) filter can be an important part of common air purifier systems promising to improve the air quality in your home or office. But there are a lot of misconceptions about the HEPA standard, whether or not an air purifier or filter truly meets the HEPA standard, and what a HEPA filter can and can’t do.
To understand how HEPA works, think of it as a mesh of tangled fibers. The sheet is usually folded into pleats to increase the surface area and filter life. Air flows through the fibers and large enough particles get trapped when they hit the fibers. So it’s a size game that very clearly helps understand what HEPA can filter and what not. HEPA works well and is effective at removing large enough particulate matter like pet dander, pollen, and dust mites.
While HEPA filters remove some particulates from the air, there are many harmful contaminants in the air that aren’t particulate matter.
VOCs: Volatile Organic Compounds (VOCs) are airborne chemicals that mostly derive from off-gassing of building materials or products in our homes as well as cleaning products aside from other sources like beauty products. The most concerning health effect associated with VOCs is that some are well-known carcinogens. HEPA filters are unable to remove VOC’s as they simply are far smaller in size than what can be trapped.
Viruses: Much like VOCs, viruses are also too small to be removed. Despite this fact, HEPA-based products were marketed for a long time with the claim to protect from viruses. The US Federal Trade Commission (FTC) has now regulated that HEPA filter-based products can no longer make that claim.
Bacteria: While bacteria are large enough to be trapped, bacteria are understood to release endotoxins into the air stream when dying on the air filter surface. Studies have demonstrated that endotoxins cause inflammatory and atopic responses in nonasthmatic and asthmatic participants.
Mold: Mold spores are large enough to be caught in HEPA filters but stay alive on the filter surface. Other particles that accumulate and fill the filter start acting as nutrients and allow mold spores to potentially grow on and through the filter membrane and eventually release new spores into the air.
It is important to say that frequent replacement of filters is critical since pathogens collected on the filter can include live organisms and eventually pathogens are re-released into the air. It is also important to note that ASHRAE estimates only 40-60% of the air within a space is recirculated through the ductwork if the HEPA filter is mounted in the HVAC ductwork and considerably less is likely to be filtered in smaller portable units. They also do nothing for surface contamination and could potentially spread the viral load beyond the area a contamination event would have naturally settled.
HVAC Deionization Disinfection: ASHRAE recommends about 6 air changes per hour through the ductwork. This implies that the air within a room is pushed through the ductwork once every 10 minutes. Deionization products create ions that remain unstable and capable of surrounding pathogens for between 30-90 seconds or about one minute on average, hoping to add enough mass to pull the air particles to the floor or into filters in the HVAC ductwork. Since these ions rely on the HVAC airflow and/or ceiling fan air mixing for distribution throughout a space, they may only treat the 10% of the room closest to the ductwork vent blowing into the room or less considering they also had to travel through the ductwork to get to the room. Turning the system up higher is not recommended by manufacturers as it potentially impacts the ability to provide preferred climate control and can create hazardous amounts of ozone and/or CO₂. The attraction of deionization systems is they are cheap, have relatively long product lives and perform well in small, controlled lab experiments. However, as far as actual disinfection in real-world applications is concerned, there do not appear to be significant independent studies confirming efficacy and they may fall far short of the intended or expected level of air or surface disinfection (safety).
HVAC UV-C Disinfection: Ultraviolet light is the only evidence-based disinfection alternative recognized by ASHRAE to be effective. Appropriately sized 254nm UV-C systems in the ductwork can deactivate airborne pathogens in the ductwork fairly effectively. However, ASHRAE also estimates only 40-60% of the air within a space is recirculated through the ductwork where conventional UV-C can safely disinfect and be shielded from human exposure, leaving significant spaces where the viral load can remain within a room. Conventional 254nm UV-C in the ductwork also does nothing to treat the surfaces within a space leaving considerable additional exposure risk whereas Far UV can treat all of the air and the tops of surfaces in a room. Second, when organisms are inactivated by 254nm UV-C, a significant amount may be reactivated by exposure to UV-A or visible blue light found in sunlight, fluorescent lights and other light sources after sanitation within a day or even hours, unlike Far UV which provides a permanent kill.
Upper Room Germicidal UV-C Disinfection: Upper Room Germicidal UV has proven to be even more effective at reducing the viral load in occupied rooms than HVAC ductwork based systems, particularly when utilized in a room with ceiling fans to provide better air mixing. Upper-Air germicidal UV-C (254nm) systems are designed not to expose people to their harmful radiation. However, when a carrier contaminates a space either with a sneeze, cough, talking, breathing or singing, gravity immediately begins to pull most of the pathogens towards the ground or other surfaces (such as desks, chairs, etc). As a result, while these upper air systems may also use air handling systems to try to fight gravity, they may not address a meaningful amount of the contaminated air and surfaces and may even keep some pathogens airborne longer which could be counterproductive. They also do not provide any surface treatment. Because Krypton lighting is safe for human exposure, it can overcome these challenges from the ceiling to the floor, providing a much more comprehensive whole room disinfection solution. Ultimately, Far UV-C provides the safest, most cost-effective, evidence-based disinfection solution for healthy buildings and vehicles.