If you’re wearing masks a lot, you might be getting some allergy relief as a side benefit, but the coils in your HVAC system are still susceptible to clogging up from all of the stuff that’s flying around.
Dirt, dust, cottonwood, pollen or anything else that is clogging or even just coating your coils is making your system work harder, so it’s wasting energy. Dirty filters make your system work harder to deliver the same amount of air.
This 2006 study by ASHRAE (the American Society of Heating, Refrigerating, and Air-Conditioning Engineers) showed that, “Good maintenance and operation practices including coil cleaning can significantly improve energy efficiency and IAQ (indoor air quality) performance of the HVAC&R systems in a building, such as reported here of 10% to 15%.”
A 2016 white paper from NADCA (the National Air Duct Cleaners Association) shows even more dramatic impacts, including an average 54% improvement in air flow, measured in CFM (cubic feet per minute) in commercial buildings, from cleaning the system.