Skip to content

When there are dangerous airborne viruses around, HVAC systems can play an important role in virus transmission rates. However, there are all sorts of misinformation currently spreading during this COVID pandemic. Some people think the right HVAC system guarantees their health while others are paranoid about running their HVAC system at all. The reality of how HVAC systems affect airborne viruses is a little more nuanced. To make the safest decisions for you and your family, you need to be informed about how your HVAC system really interacts with viruses. JW Plumbing, Heating & Air in Los Angeles, CA, wants you to know all about whether you can or cannot spread viruses through your HVAC system.

Myth 1: UV Light Air Purifiers Keep You From Catching COVID

Since it was first found that UV light can kill virus particles, many people have jumped on the idea of using UV lights to clean air as it flows through filters. UV light filters are a very effective way of cleaning the air in general. They can kill off bacteria, molds, and other airborne particles, including some viruses. However, UV purifiers also come with some downsides that keep them from automatically being a safety guarantee.

First of all, the levels of UV light needed to kill the coronavirus are so strong that they would fry any exposed skin. This means you cannot just stick these filters all over the building and guarantee safety. They need to be installed inside of an HVAC system or on the ceiling, where concentrated light levels cannot come into contact with anyone. Furthermore, UV lights can only kill virus particles when the virus travels right next to them. If an infected person breathes out virus particles, you may easily come into contact with them before a building’s UV purifying system kills the virus. Ultimately, UV lights help reduce COVID levels, but you should never let the presence of UV filters encourage you to disregard other virus safety protocols.

Myth 2: It’s Unsafe to Be in a Building With a Running HVAC

While some people are being too confident in the protective powers of HVAC systems, other people are experiencing the opposite problem. Many people fear running their HVAC at all because they think it could pick up virus particles from an infected person and spread them all over the building. It’s true that viruses can recirculate through air systems and infect people in different parts of a building. However, the good news is that there are some simple ways to adjust a system and address most of these problems.

One of the biggest changes recommended by the CDC is changing airflow. Having horizontal airflow makes it easy for viruses to spread from one person to the next. Switching to vertical airflow, from the ceiling to the floor, provides people with a constant flow of clean, fresh air. In buildings with high and low-risk areas, like an office with a waiting room and private offices, change the direction of air travel so that it goes from the clean to not-clean areas. This can often be done just by moving around a few ducts and installing air curtains between rooms. A few basic adjustments make a big difference, so you should never just give up and assume an HVAC system will automatically infect everyone in the building.

If you are concerned about recirculated air infecting you, you may also want to look into better ventilation. This pulls in clean air from the outside, reducing levels of COVID in your indoor air and ensuring you are not breathing air just exhaled by an infected person. Opening windows to bring in the fresh air can also help temporarily, but keep in mind that most systems are not set up to rapidly handle a lot of outside air. Adding more ventilation should preferably be done with the help of an HVAC professional, so they can help improve ventilation without sacrificing performance. The right sorts of fans and other ventilation equipment can help improve both performance and safety.

Myth 3: A HEPA or MERV Filter Can Catch All Virus Particles and Keep You Safe

Another big myth about HVAC systems is that you can use a HEPA or MERV filter to catch any virus particles as they cycle through your heater or air conditioner. Just like UV lights, the truth is that these filters can help, but they are no guarantee of safety. There are all sorts of air filters and portable air cleaners that use tightly woven HEPA or MERV filters. Filters of a MERV 15 rating or higher have been shown to block some of the airborne droplets that contain COVID. However, smaller particles may still be able to move through the filter and remain in circulation.

Something else to keep in mind is that high-efficiency filters can actually cause problems if you put them a system that’s not designed for these filters. This can cause the filter to load up with dust and other bigger particles too quickly, and then the air just ends up bypassing the clogged filter anyways. Like UV air purifiers, high-efficiency filters only remove some virus particles from the air. Standing by a person who is not wearing a mask, touching an infected surface, or joining a crowded area can still be just as dangerous regardless of filter options.

Myth 4: HVAC Increases COVID Transmission Due to Lower Humidity and Temperature Levels

Another reason some people worry about running their HVAC system is that they think certain temperatures and humidity levels may be dangerous. The reality is that temperature and humidity have a slight effect on virus rates, but it is not a cause of major concern. Research has shown that COVID tends to be slightly more infectious at low humidity rates and colder temperatures. This happens because the virus flourishes at certain temperatures and humidity levels, while humans are more likely to get sick when the air dries out nasal membranes. However, this fact does not mean you should be turning off your air conditioner, cranking up the heat, or running a humidifier nonstop.

High levels of moisture in the air allow other bacteria and molds to flourish. This can result in respiratory infections that actually make you more susceptible to dangerous COVID symptoms. Furthermore, high humidity and heat can worsen other health conditions, and being unhealthy puts you more at risk for COVID infections. Keeping temperatures at levels safe for human functioning is still the best option. If you want to adjust humidity, try to keep it no higher than 50 percent. This will add some moisture to the air without allowing for mold growth.

As you can see, there are all sorts of misconceptions because people do not fully understand how HVAC systems and virus transmission work. If you would like to learn more about creating an HVAC system that keeps residents safe, JW Plumbing, Heating & Air is here to help. We assist Los Angeles Homeowners with a variety of plumbing, cooling, and heating services. If you have any questions, give us a call. We would enjoy telling you about how we can serve your home climate comfort needs.