No Toil Castle, One-Year HVAC Furnace Filter, 20” x 20” x 1”

Q: How do you determine the point at which it fails?

They are supposed to last for 1 year - I've had mine almost a year and it seems to be doing the job. I live in Arizona so my a/c runs 24 hours a day during May thru Oct (almost 6 months out of the year) so this particular filter is my first choice. I love it! Hope this helps!

Q: Do you make 12x12 and 12x24?

Does it help with cat hair and cigarette smoke

Q: Does this work for one year?

YES. All the Castle filter have a 1 year rating. Tests from a independent lab (LMS labs MN.) Show that a standard pleated filter hold a little as 5.2 grams of dust before failing. The Castle Filter holds 123 grams of dust before failing. You would have to buy up to 20 pleated filter to hold the dust of one Castle Filter. Castle filter have been used in very dirty area like Phonenix AZ, and lasted one year with no service. If you desire you can service your Castle filter as many times in a year as you what. If you have a very dirty area pets, duct on floor you can vacuum your Castle filter with a Furniture brush. This will not remove the anti-microbiales in your filter that reduce mold growth.

Q: I read it's treated to prevent mold growth but does this filter mold spores?

Mold spores can get down to the 10 micron and smaller size range. Castle Filters capture about 95% of 10 micron particles, and about 90% of 5 micron particles.