As I compose this article, COVID-19 is in full force here in the US. It remains a daily topic of conversation and news.
Like everyone else, we’re trying to learn everything we can and take the proper precautions to stay safe in these dangerous times. But we’re also fielding questions about HVAC systems. Can they transmit COVID? Can they protect against COVID? What should I be doing to keep my family healthy?
We’re not medical experts, but we are HVAC experts. And as new studies and data pours in, we’re able to start forming some tentative conclusions.
To be clear, much of the information from any source is going to be subject to further study. Anything in this article is no exception. However, we have decades worth of information on HVAC systems as it relates to numerous illnesses and virus strains, including some that are very similar to the coronavirus.
Utilizing that information, when it’s corroborated by recent studies and expert recommendations, we can begin to form solutions that should benefit any home.
We’re going to walk through some of the problems that can be associated with HVAC systems and illnesses. Then we’re going to talk about solutions. The lack of testing for COVID specifically means that some conclusions will need to remain speculative, but the data we have for HVAC systems and other viruses and illnesses will allow us to draw more confident conclusions when discussing overall health implications.
Indoor Air Quality Problems
The perennial problems:
- Seasonal flu
- Respiratory issues from mold
- Other irritants such as pet dander or pollen
The “new” problems:
- Air quality for immunocompromised or otherwise at-risk populations
- Maintaining air quality and health during quarantines and limiting transmission between building inhabitants and/or families
To be clear, the “new” problems have always existed in some form. We’ve even seen the spread of other coronaviruses in the world, though obviously not to the same extent as with COVID-19.
But even something as simple as not passing around the seasonal flu when one of your kids brings it home from school can be a serious issue.
Solutions do exist. None are foolproof. Together, though, they can make a difference.
Indoor Air Quality Solutions
According to the Environmental Protection Agency (EPA), running an HVAC system can be part of a larger plan to protect those in your home.
So what is that larger plan? It involves several factors, each of which can contribute significantly to the health and safety of those in your home. These areas can include:
- Proactive humidity control
- Proper filtration management
- Air purification options
- Non-HVAC best practices as recommended by expert health organizations
We’re going to dig into each of those, but it’s important to note that there’s no silver bullet here. Even a carefully-defined, proactive approach to mitigating COVID and other illnesses isn’t foolproof. However, when combined, they represent a significant improvement in the risk level of you and those closest to you.
Recent studies from such institutions as Yale and The American Society for Microbiology have shown that low humidity levels can contribute to the transmission of the flu and other airborne illnesses. Low humidity environments, they find, are ideal for SARS coronaviruses to proliferate and survive.
These levels were found to be anywhere from 20% to 40% humidity. At this relative humidity range, coronaviruses survive on surfaces for a far longer period of time. This has obvious implications for areas used by multiple people.
The Yale study also found that humans’ ability to fight infection and recover from it was reduced at low humidity levels. Both in the prevention of sickness and removal of the illness from the body, functioning is impaired at low humidity ranges.
This is of biggest risk in the winter months, when humidity is historically at its lowest. Even here in Ohio, relative indoor humidity can reach as low as 15% in the winter months.
While the opposite - high humidity levels - can be a problem for other reasons, the goal is to keep humidity levels in an acceptable range at all times.
The ideal humidity level for a home is often cited as 40% to 50%. Anything at or above 60% creates an environment for potential problems, and anything lower than 40%, as we’ve seen in the studies cited, can increase the risk of infection. A similar study from Munters found nearly identical results, with the highest levels of virus inactivation coming at 50% humidity.
Controlling Your Humidity
For entire homes, the portable humidifiers you see in stores aren’t going to cut it. These can be used in specific situations, but the only way to ensure proper humidity levels year-round is with humidity-controlling HVAC products.
Ducted, whole-home humidifiers are the most obvious solutions to those dry wintertime conditions. They can proactively manage humidity levels to keep you within safer ranges.
In the summer, your air conditioner actually goes a long way toward dehumidifying your home. For very humid climates or, say, houses that have damp basements, adding a whole-home dehumidifier is often necessary to stay within acceptable ranges.
These recommendations will change based on where you live. Don’t have a basement? You may not need a dehumidifier. Live in a humid coastal area? You may never need a humidifier, even in the winter.
Regardless, the research appears to be clear, and it matches what we’ve known about seasonal flu viruses for a long time. Plan accordingly, and you’ll be able to mitigate your risk significantly in the most dangerous months of the year for coronavirus and other viral infections.
Air Filtration and COVID
The National Air Filtration Association (NAFA) reports that, while there isn’t a “best” filter to prevent COVID-19 and similar viruses, anything below a MERV 8 filter will be significantly less effective.
MERV stands for Minimum Efficiency Reporting Value. It’s a measure of how well a filter can remove certain microscopic particles from the air.
The American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) corroborates this, with evidence that suggests that filters at or above MERV 13 would be required to significantly reduce novel coronavirus particles. As NAFA reports, DNA and RNA from similar virus strains that travel via droplets (as coronavirus is widely assumed to travel) have been found on HVAC air filters.
Controlling Your Filtration
This is all interesting information, but it’s entirely academic unless it’s applied to a home. So what can you do to make a difference in filtration?
Several things, it turns out. Here are a handful:
- Check and replace your furnace’s air filter on its recommended schedule. This could be as little as 60-90, up to about six months for some larger filters.
- NAFA recommends wearing gloves when you replace your filter, and assuming that there are active microbiological materials in them when you do so.
- Upgrade your system’s air filter to one that is both higher MERV while maintaining compatibility with your HVAC system. Higher MERV on its own isn’t always good if it isn’t designed to work well with your system.
- If your system allows for it, run the system’s blower fan for longer periods (or continuously), even if you aren’t heating or cooling. The reason being, your filter is only clearing the air when the fan is running. Many modern HVAC systems will allow fan-only use, regardless of whether or not the furnace or A/C is running.
The bullet up there about upgrading your filter is important, but we want to stress that it’s not always a great idea unless you pick the right filter. If you upgrade from a low-MERV one-inch filter to a very dense one-inch filter, for example, it can inhibit airflow. This is potentially damaging to your system in other ways, some of which will ultimately be related to air quality.
At Fire & Ice, we often recommend Aprilaire’s four-inch media filters, which have great filtration while still allowing for ample airflow, don’t need to be changed as often as many filters, and can be purchased at MERV ratings that will effectively trap particles the size of coronavirus.
UV Light & Ionization
In the search for solutions, many customers have asked about UV lamps and similar air purification technologies.
UV lamps have shown effectiveness in reducing infections from numerous types of viruses. Importantly, they have not been tested on COVID-19 to date, but have proven effective against several similar viruses. These viruses include MRSA, Strep, Listeria, Norwalk, Bird flu, and Tuberculosis, among others.
UV light requires particles to pass through it in order to be effective. This makes the installation and placement of a UV lamp very important. While there are some DIY options, it’s generally best to have it installed by a professional HVAC installer.
Ionizers are intended to neutralize the particles themselves by binding them into an inert form, whereas UV lamps simply kill organic material.
Controlling Your Air Quality
At Fire & Ice, we regularly install the Reme Halo Air Purifier in homes. We love this product because it utilizes both UV and ionization techniques, and proactively disperses particulates into your ductwork that will react with viruses.
To reiterate, no testing has been done on COVID-19. Here is the statement from RGF Environmental Group, the company that makes the Reme Halo:
“We currently do not have testing on the Wuhan Coronavirus (COVID-19). We are evaluating testing options with partners in both the U.S. and China. As there are a limited number of facilities capable of testing for this virus, their focus is on prioritizing testing as it relates directly to recent outbreaks.
“COVID-19 is a member of the enveloped RNA Coronavirus (subgenus sarbe covirus Orthocoronavirinae) subfamily. While RGF does not have testing specific on COVID-19, we have validated test results showing 99+% reductions on similar viruses. These viruses, like COVID-19, are also ‘enveloped’ or protein jacketed virus types. If we can reduce these virus types, an assumption can be made that we would also be effective at reducing the current Coronavirus at hand. Important to note that we make no medical claims.”
The lack of certainty can be frustrating for some, but the past results from the Reme Halo, and other products of similar intent, is promising.
Going Beyond HVAC For COVID Protection
None of this is intended to replace day-to-day best practices to protect yourself from the coronavirus. We pay close attention to CDC guidelines and incoming studies that inform our practices as an HVAC company, and also that will inform our conduct as individuals and citizens working toward the common good of eradicating the virus.
Wearing masks and gloves at appropriate times, social distancing responsibly, thoroughly and regularly washing your hands, and maintaining a clean environment in your home and professional life are all recommended practices that experts have agreed upon.
While no HVAC measure can ensure your health and safety, we hope it’s clear that when a full plan of action is created, your HVAC system can work with you in the fight against not just coronavirus but other viruses and illnesses as well.
No-Contact Service Calls
We’re doing our part at Fire & Ice. HVAC services were deemed essential during the coronavirus lockdowns, so we’ve been hard at work helping our customers throughout the pandemic, and will continue to do so for as long as it lasts.
To help assuage any concerns that our customers may have, we’ve instituted no-contact service calls, as well as a number of other safety precautions in our offices. We remain compliant with all guidelines as dictated by state or national mandates, and have been able to operate safely through the pandemic.
Americans spend about 90% of their lives indoors. These issues are always important, but have never been more important than they are right now.
If you have questions regarding our practices, or are in the Columbus, OH area and would like to schedule your own “no contact” in-house estimate or service call, we hope you’ll give us a call today!