I have used your filters for years. I started when I purchased a new Air conditioner for my house. In the last few times I've used them they now make a loud vibration sound. I went from merv 13 to 11 now I'm thinking I should go down to 8. I don't want to I like that they take so much out of the air. Did you change something :thinking:.
I purchase the 20 x 20 x1 furnace filters. It actually reminds me to change the filter more often and easier on the fan and circulation. I will say the filters are a little undersized compared to units I have boughten locally For buying in multiple units It is cheap just to change more often.