The World Health Organization has determined that environmental factors such as poor indoor air quality, poor water quality and noise pollution are detrimental to the overall health of the world’s population. The CDC Interim Guidance to Businesses and Employers recommends all businesses “increase the amount of air exchanges in the common work areas and other rooms employees share,” said CDC Director Dr. Robert Redfield during the April 8, 2020, White House coronavirus briefing.
The COVID-19 pandemic has brought to light the dangers of stale indoor air, poor air quality and the environmental dangers that disproportionately impact workplaces across the nation. These dangers impact workers who work from home during the pandemic, the stay-at-home orders and quarantines. It is imperative that every workplace (and home) follow the recommendations of the CDC for frequent fresh air exchanges with outside air. To limit liability and be competitive in a post-COVID-19 economy, employers must provide for the care and safety of employees, customers and their families by optimizing workplace indoor air quality and minimizing airborne viruses.
Using the HVAC System to Minimize Airborne Viruses and Optimize Indoor Air Quality
Fortunately, there are proven ways to use one’s HVAC system to minimize airborne viruses and optimize indoor air quality. But if the wrong type of device is chosen, or the wrong size is installed, the science shows they just don’t work. Here are the benefits and limitations of each:
HVAC UVC Coil Sanitizers: Much has been written and discussed in the press about the use of ultraviolet (UV) light to sanitize hard surfaces and even masks for healthcare workers. UV light comes in three distinct wavelengths with three very different functions: UVA, UVB and UVC light. UVA is the art and party wavelength, also referred to as “black light.” This is the light that causes fluorescent paints and dyes to glow. UVB is the light in tanning beds and medical skin treatments. While UVB can sanitize hard surfaces, it takes a long time and a very bright UVB bulb. UVC is the wavelength of choice for sanitizing surfaces, water and even air.
Its benefits are:
- UVC light kills viruses, bacteria and mold on surfaces like the HVAC condenser coil and drip pan as well as sanitizing the air flowing over the UVC bulbs and any water in the drip pan or on the coil.
- UVC light eliminates viruses, mold and bacteria in ducts by removing the source on the coil
- UVC light must meet three criteria to be effective:
- must be Type C UV light (aka UVC)
- must provide 30 watts of UVC light power per square inch. This requires that the UVC light source be a 40-watt bulb (or equivalent) located no further than 18 inches from the furthest part of the coil to be sanitized.
- must shine UVC light on all sides of the coil (at least two bulbs, top & bottom).
Its limitations are:
- Most DIY and even professionally installed UV sanitizers fail to meet all three criteria. For instance, most have only one 20-watt bulb, which is too little to be effective as a sanitizer.
- UVC light is dangerous, and an automatic shut off switch must be installed on the air handler access door to ensure the UVC light does not come on while the access door is open. UVC light works by damaging DNA and can cause skin cancer and even cataracts with unprotected exposure to UVC light.
Ozone Generators: Ozone has been used for decades by municipal water departments, public swimming pools, commercial aquariums and even fish farms to sanitize water. It is cheap and easy to produce but can be hazardous if breathed in over time. In copy centers and office buildings, ozone is an indoor air pollutant. However, small amounts can be introduced into the HVAC system to sanitize the air handler and ducts and then dissipate back to plain oxygen before entering the living or work spaces.
Its benefits are:
- Ozone generators introduce charged ozone molecules into the air inside the device, which in turn creates a charge on airborne particles of viruses, dust, pollen, mold, bacterial spores and smoke particles. These charged particles become trapped in a removable filter or degrade due to the damage caused by the ozone.
- Ozone generators must be professionally installed to ensure the unit is properly sized for the HVAC system so that no ozone enters the living or workspace.
Its limitations are:
- Most DIY ozone generators do not provide enough ozone to sanitize the coil and ducts. In addition, DIY ozone systems often allow ozone to leave the HVAC system mixed with the “cleaned” air. This ozone contributes to poor indoor air quality — essentially trading one problem for another one.
Whole Building Smart Ventilation Systems: Smart technology now exists for HVAC systems, and it’s emerging as not only an extremely efficient way of saving energy — and, in turn, money — but also as a way of reducing airborne viruses and enhancing health for employees and customers alike.
Smart ventilation systems improve Indoor Air Quality (IAQ) by using outside air to exchange for indoor air when the outdoor air quality is better than the indoor air quality. This is accomplished by a smart controller that uses a system of sensors to determine when to open dampers that allow outside air to be drawn into the building and stale indoor air to be expelled. By optimizing indoor air quality, the environmental stress caused by exposure to poor air quality is reduced/minimized, thus reducing overall annual risk of heart attack, stroke and viral infection. Artificial Intelligence analysis of Social Determinants of Health (SDoH) found that the relative risk for death by heart attack or stroke increases 14 percent when a person lives and works breathing poor-quality indoor and outdoor air. Similarly, the risk of developing serious infection after exposure to COVID-19 is significantly increased when a person lives and works breathing poor quality indoor and outdoor air.
Its benefits are:
- Smart ventilation systems monitor outdoor and indoor air quality and exchanging the indoor air for outdoor air when the outdoor air quality in better than the indoor air quality.
- Smart ventilation systems expel airborne virus particles as well as dust, pollen, mold, bacterial spores and smoke with the exhausted stale indoor air.
- Smart ventilation systems expel gasses like volatile organic compounds (VOCs), pollutant gases, odors, carbon dioxide, carbon monoxide, formaldehyde, sulfurous gasses, nitrogenous gasses, radon, etc. with the exhausted stale indoor air.
- Smart ventilation systems optimize the indoor air quality based on the best available air quality, adding outdoor humidity as needed or expelling air when the indoor humidity is subpar.
- Smart ventilation systems utilize outdoor air instead of running the compressor when outdoor temperatures are appropriate to cool or heat the indoor space, thus extending coil drying time and eliminating the water required for mold and bacteria growth.
When it comes to combatting COVID-19, with some professionally installed modifications and annual maintenance, one’s HVAC system can and will remove airborne viruses and other indoor pollutants before they impact one’s health or the health of one’s employees, customers and their families.
Allison A. Sakara, RN, MSN, NP, PHRN, is managing member & regulatory affairs specialist with the Lake Wales, Florida-based Natural Air E-Controls, LLC. Natural Air E-Controls, LLC designs and builds HVAC control systems that enable the building’s HVAC equipment to provide fresh air and remove pollutants by taking in outdoor air in amounts needed to improve indoor air quality while saving on heating and cooling bills.
