How HVAC Technology Fights Covid-19 – EAC, HEPA Filters, UV Lamps & More

Connect With HVAC Schools

When America emerges from rolling lockdowns, HVAC technology will play a critical role in protecting office, retail, and school environments from the spread of Covid-19.

Scientists are still learning about the ways in which the new coronavirus is spread. The most common method of infection is droplet transmission: infected material expelled from someone’s cough, sneeze, or breath. Droplets generally only travel a few feet; hence social distancing guidelines. But there’s also the possibility of aerosol transmission: when the expelled particles are so small that they linger in the air and travel on air currents.

While there is debate around how dangerous aerosol transmission is, it’s understood that it can and does happen in indoor environments. According to the Centers for Disease Control and Prevention (CDC), there have even been possible cases of some air conditioner units exacerbating the spread of Covid-19 through airborne particles. More research is needed. In the meantime, home, office, retail, and school environments will be looking at their HVAC systems to try and find ways they can prevent aerosol transmission.

HVAC systems act as the lungs and veins of the built environment. When we keep them healthy, we keep ourselves healthy. To get a look at the ways in which HVAC technology can fight back against the spread of Covid-19, read on.

Air Filtration and Purification

“With the Covid-19 pandemic on everyone’s mind, air purification is of utmost concern,” says Clint Shurtleff, Heating and Refrigeration Department Manager at New England Institute of Technology (NEIT). “Using a modern duct heating system is the most efficient way to clean and purify the air if properly installed with the ancillary equipment. This type of system can provide a very high level of confidence for the elimination of airborne contaminants within the structure.”

The first line of defense is to replace all low-grade air filters with High-Efficiency Particulate Air (HEPA) filters. HEPA filters are effective for viruses, but may not be 100 percent effective after only one pass through the filter. If the system is set up as a Constant Air Circulation (CAC) system, the filter may operate in the range of 99 percent effectiveness.

Researchers from Tel Aviv University have recently found that Covid-19 particles can be killed with ultraviolet light-emitting diodes (UV-LEDs). In less than 30 seconds, researchers were able to destroy more than 99.9 percent of the coronavirus. Disinfection systems based on these bulbs could be installed in a ventilation system and/or air conditioner, and sterilize the air that passes through them. This could be a breakthrough: the types of bulbs the researchers used are cheaper, safer, and more plentiful than the existing alternatives.

“Along with the HEPA filters, UV lamps installed within the plenum of a warm air system have been shown to reduce infections from viruses,” Shurtleff says. “UV radiation has been utilized to disinfect air, water, and nonporous surfaces and has been shown to destroy the outer protein coating of the SARS virus. It may be effective in destroying the Covid-19 virus in the same manner because both are coronaviruses.”

But there are limitations as to how effective UV radiation may be when inactivating a virus, and UV radiation only works effectively if the virus has direct exposure to the radiation. Furthermore, UV radiation can cause injury to skin and eyes if individuals are exposed to it for any period of time. As a result, UV lamps are commonly installed within the ductwork of an HVAC system.

Some advanced home air purification systems can outperform HEPA filters: particularly, Electronic Air Cleaners (EAC) with pre-filters and electrostatic charging plates. These electronic filters can trap up to 99 percent of contaminants as small as 0.1 microns in size. By comparison, the Covid-19 virus is 0.12 microns. But it’s not a set-and-forget technology: it requires regular maintenance that takes appropriate precautions.

“The pre-filter should be cleaned or changed every six to 12 months to maintain proper operation,” Shurtleff says. “When changing filters it would be wise to assume that there may be some active microbiological material on them. With this in mind, take precautions in handling the filters. Wear a quality mask and gloves, and dispose of them in a plastic bag, and, if renewable, clean them outside in the fresh air. Make sure to dispose of gloves and mask in the plastic bag and sanitize tools and your hands.”

HVAC Client and Technician Education

Today’s HVAC technicians need to be both masters of their trade and effective educators of their clients. Each client’s needs will be different, and it’s in part the responsibility of the HVAC technician to not only present solutions, but help the client understand how they work and why they are necessary.

“With Covid-19 surging across the country, this is the opportune time to educate the homeowner as to the equipment that is available to help improve indoor air quality,” says Brian Sullivan, Assistant Professor of Refrigeration, Air Conditioning, and Heating Technology at NEIT. “Very few homeowners understand how their systems work and what is available to improve their lives. This is the job of the technician. Remember, it is hard to come back from a bad first impression, so it’s up to the technician to be knowledgeable and possess strong technical skills.”

The Covid-19 pandemic is also changing the HVAC landscape, and HVAC technicians need to stay educated on new standards, practices, and research. As the world adapts to Covid-19, HVAC technicians are increasingly being called upon to help design the future of the home, office, retail, and school environments.

“To remain up to date with changes in the HVAC industry, there are several resources available to the technician,” Sullivan says. “The first and foremost is the Internet.”

Shurtleff and Sullivan also recommend trade organizations and publications from the Refrigeration Service Engineers Society (RSES) and the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE), and government publications from the Environmental Protection Agency (EPA) and the Centers for Disease Control and Prevention (CDC), which all provide valuable information.

“Trade magazines are usually free, so technicians should subscribe to them,” Sullivan says. “Supply house training is helpful, too. If available, a company service manager or someone in a similar position can research and provide new information to the technicians. They may also conduct training sessions. Creativity is important to keep technicians well informed.”

Matt Zbrog

Matt Zbrog is a writer and researcher from Southern California. He's been living abroad since 2016. Long spells in Eastern Europe, Southeast Asia, and Latin America have made the global mindset a core tenet of his perspective. From conceptual art in Los Angeles, to NGO work on the front lines of Eastern Ukraine, to counterculture protests in the Southern Caucasus, Matt's writing subjects are all over the map, and so is he.

Related posts

smartphone-smart-home-200x200

September 15, 2021

“Intelligent” products, including a variety of smart thermostats that are already on the market, give consumers more personal control over their homes through the use...(more)

renewable-wind-solar-panels-200x200

September 03, 2021

Huge bills from the energy companies face homeowners and building managers, especially during the record-setting heat and cold weather prevalent this past year. Solar power...(more)