“It’s a helpful approach to monitor the pressure drop across the filter – it’s a good way to know when the right time to change the filter is, otherwise there’s a lot of guesswork involved,” says Li. She says the typical three-month replacement recommendation on the This is based on the assumption that your HVAC system is running 20 percent of the time (approximately five hours per day). A lot of this depends on your climate, but Li says a recent study found that the average HVAC life of 20 homes over a year in Toronto was 10 percent, meaning these people could be replacing their filters less often.
As for the MERV 13 ruling, Li says that higher flow resistance causes the HVAC fan to work harder. Depending on your system, the fan could stop work so hard, reducing airflow and potentially damaging the cooling coils. However, a higher MERV value does not mean higher flow resistance. That depends on the filter quality, as Li says she has seen MERV 13 filters with lower flow resistance than a MERV 8. Ultimately, the main factor, according to Li, is the age of your HVAC system.
“If it’s a relatively new system in good condition and you’ve used MERV 8 filters with no problems, then I don’t think it’s a good idea to use MERV 11, MERV 13 or even MERV 14 filters just because of that There will be problems. If there is a difference in flow resistance, it is relatively small,” she says. “I think most systems can handle it, especially if you don’t change filters throughout the year.”
People with older systems should be careful as they may not be able to handle high-efficiency filters at all. She suggests listening to the sound and feeling the flow coming from the cooling and heating vents in your home.
The good news is that Woosh’s smart filter can detect problems with your HVAC system. The company says it can detect early signs of coil freezing, which if not addressed can result in irreparable damage. This is achieved by checking the pressure drop and flow rate as well as the temperature and humidity values.
Luckily, using a MERV 13 filter doesn’t seem to have any negative effects on my system and I haven’t received any notifications of problems with my HVAC. My only concern is that according to the app Despite it I don’t need to change my filter even though it’s been nine months since I installed it. My wallet is happy, but everything I’ve heard and read about filters suggests I should have changed them by now.
