I've always used this filter to help with my sons allergies, it seems to filter out a lot of the particles that bother him, I've been very pleased with the results.
I've been using this filter in sizes 20x30 and 20x20 for over one year and definitely see a difference. There is less dust in the house, the air is cleaner because it filters out the harmful particles in the air. It costs much more than the cardboard ones but it does its job for the price. I have a 3 year old TRANE air conditioner and want to make sure to use the best products for it and that would be FILTRETE!
This filter is worth every penny. Our whole family suffers from allergies, particularly ragweed and cedar. These filters make our home our refuge and our respiratory systems calmer. I found this out when we tried a lesser particulate filter and different brand. I have switched back and won't gamble with that again!
Previously I have used cheaper replaceable filters or washable reusable filters. I say previously because since I have switched to Filtrete's Healthy Living filters, I have found that my home is not as dusty and those in my home who have allergies report that they are suffering much less of the time.
I always use Filtrete filters and love the amount of "stuff" it takes out of the air in my home. I live in a dusty area so it is important to use a quality filter. My only complaint is that the filters are a 1/8 to 1/4 too big for the opening and I always have to pry them in with a screwdriver. The result is the cardboard around the filter is wrinkled and bent by the time I get them in. And with 10 foot ceilings it is hard to stand on a ladder to push them into the opening. I am what most would call a senior citizen and soon I will have to hire someone to change the filters because they are so hard to get into the opening. I would recommend them with limitations.
I have been using this filtration in my forced air unit, and just recently, when I went to change it, it was "distorted", like it wasn't able to stand up to the pressure of the air flow? I had never had one do this before, so we'll see if there has been a change in the manufacturing process, or just a one-time thing.