Using Your HVAC System to Help Prevent COVID-19
Serving Clark County & Portland-Metro Area
There are still various questions surrounding COVID-19, how it’s spread, and the role HVAC systems may play in transmitting the virus. However, the Centers for Disease Control and Prevention (CDC) says because the virus is a respiratory illness, the easiest way it’s spread is through respiratory droplets.
Theoretically, respiratory droplets could be distributed through your HVAC system, but researchers say it’s highly unlikely. Still, there are steps you can take with your HVAC system to help prevent COVID-19 as REHVA, The Federation of European Heating, Ventilation and Air Conditioning tells the RSES Journal.
Increase Ventilation Efforts
If your building uses a mechanical ventilation system, REHVA recommends you change your timer settings so that the building is being ventilated at nominal speeds for two hours before people begin arriving. Then, reduce the speeds for two hours after the building has been evacuated.
If you rely on an in-demand-controlled ventilation system, change the carbon dioxide setpoint to lower than 400 ppm. This will make sure your system is operating at optimal speeds.
Do Not Turn Ventilation System Off
Whether your building isn’t being used for the time being, or it’s a weekend, keep the ventilation on at reduced speeds 24 hours a day. Do not switch it off. The general idea here is to bring in as much outdoor air as possible.
Increase Airflow by Opening Windows
If your building doesn’t have a mechanical ventilation system, it’s recommended that you open windows to increase air circulation.
Keep Your Bathrooms Well Ventilated
According to the CDC a previous Coronavirus, SARS-CoV-2 was transmittable through fecal matter. While it hasn’t been confirmed, at the time of this article if COVID-19 can be transmitted through fecal matter or by flushing toilets, researchers do recommend people flush toilets with the lid down and keep bathroom ventilation systems on 24/7. REHVA also suggests opening windows for added ventilation. However, they say if you have a passive stack or mechanical exhaust systems, opening a window may cause contaminated airflow from the bathroom to other rooms. If this is the case, you’ll want to avoid opening windows in your bathrooms.
Don’t Change Your Air-Conditioning and Humidity Levels
According to REHVA, changing your humidity levels and air-conditioning levels isn’t helpful in combating COVID-19. They say with other viruses you can change these levels to help reduce transmission, but with COVID-19 it isn’t helpful because the virus is resistant to environmental changes. In fact, they say Coronaviruses are susceptible only for a humidity level above 80% and temperatures above 86 degrees Fahrenheit–which will lead to microbial growth and affect your comfort.
Keep Air Handling Units with Recirculation to 100% Outdoor Air
If your air handling unit has a recirculation damper, keep it fully open to circulate fresh outdoor air, even if your system has return air filters. Keeping the dampers closed may lead to problems with heating and cooling capacity.
Ensure Leaks in Heat Recovery Equipment are Controlled
Regenerative air-to-air heat exchangers, known as enthalpy wheels and rotors can suffer leaks due to poor design and lack of maintenance. Ensure your leakage rates are below 5%, and that your system has been properly installed. More often than not, HVAC contractors find fans have been mounted so that higher pressure on the exhaust air side is being created, causing leaks into the air supply.
Switch Fan Coils Off
Fan coil systems and induction units often work with local circulation. If you can, REHVA suggests you turn off fan coils to help avoid resuspension of virus particles at room level. Although fan coils have filters, REHVA says they don’t filter out small particles because the filters are coarse.
If you’re unable to turn off your fan coils, REHVA recommends the fans be operated continuously. This way any particles will be removed with exhaust ventilation.
While a lot is still unknown about COVID-19, these are just a few suggestions you can take into consideration with your HVAC system. To review REHVA’s recommendations in their entirety take a look at this RSES Journal, and if you have any questions about your HVAC system, contact us. We proudly serve the Vancouver WA area.
Using Your HVAC System to Help Prevent COVID-19 in Vancouver WA
Serving The Greater Vancouver WA and Clark County WA Areas