I buy these routinely for my country home. The filters typically last about 3 months. They trap a lot of soot from my scented soy candles in addition to the dust and pollen. My air handler takes an odd size that I can't find locally, so I am very happy to order these.
I really havent had the filters for over a month. I have not changed it out. Therefore, I havent seen how dirty or how effective it was in itss use. I did purchase enough for a year.
I made a shop dust filter to filter the air in my shop. I do already have a dust collector that can be hooked up to my dust-making power tools.I chose only MERV 8 because so much of the dust is easily captured by that.
We have been using Filterbuy for 2 years. Being able to set up recurring order of size and quantity is so easy. Never have to shop with my feet looking for size and lowest cost