Filterbuy 20x20x1 Air Filter MERV 13 Smoke & Allergy Defense (4-Pack)

We used these to build Corsi-Rosenthal boxes for high grade air filtering. Works really well for that purpose.

Good price and quick delivery

Great product

So i have switched from Merv 11 filters, because lately i have been having allergies which i have never had before. I have been having a problem with humidity in my apartment and the air handler has mildew. So while i am waiting on a dehumidifier, i have installed these filters and have noticed that my stuffiness has gotten better within the two days i put the filters in. Merv 13 filters are supposed to be able to catch mold, so if that is the case it is doing its job. I have not noticed any difference in AC operation, my Ac is not having a problem pulling air through this compared to the Merv 11. I also smoke bud in the house, and i notice that it completely eliminates the smell which is quite surprising, it's not something that i would expect from a filter that doesn't have say .. "charcoal". The only reason i gave this filter a 4 and not a 5 is because the filter corners came in damaged, even though the shipping box had no damage at all, which makes me think they packaged the product with damage and still shipped it.. fortunately it doesn't affect the operation of the filters. Also to people who say this is the wrong size, they need to understand that ALL filters run smaller then they are intended to be. These were 19.5 inches which is just fine, i've had no issue and will be buying these again. p.s. can't beat the price for merv 13.

I think all disposable filters are very similar if you match the MERV rating. Therefore this filters are a good quality and excellent value.

These are worth the money!

Used these to make a box fan filter. Seems to work fine.

The 20x20" size of furnace filter is in demand among handy types because you can turn on a 20x20" box fan, slap a furnace filter on the intake side, and it'll stay there and collect dust. It's a fast, cheap, portable, and effective dust collection system. At the moment, I'm using mine to make a positive-pressure filtered-air system to protect my employees from potentially contagious customers. Better than nothing, and affordable. Make sure the fan's getting enough air through to keep from overheating. If you seal the open triangles at the top and bottom, you can mount two filters on the back of the fan at angles, and it'll improve airflow and reduce the stress on the fan, plus the filters will last longer. I've never received a shipped filter that wasn't slightly dented, but it didn't affect the structural stability or usability of these.

Great product, great price and even greater customer service. Had to deal with customer service and was really impressed : fast and took the right decision. Made a ‘’home HVAC’’ system for under 100$CAD: - 4 Merv 13 filters - white duct tape - bottom cardboard (the one used for shipping the filters) - 20’’ fan More powerfull and effective than most HVAC systems but without the docking in each room.

I taped a single Merve13 filter to a 20" fan to build a free standing air filter. I also taped four, 5" X 20" X 20" Merv 13 together with a 20" fan to build a second free standing unit. Both cleaned the air in my 2,400 square foot house after a few minutes - checked it out with an air quality meter. Not much 'cleaning' difference in the two except the 5" one with a much greater filter area will last much longer before it needs to be replaced. I have a 5' filter in my furnace as well and change it every 6 months, but it probably would easily last a year. After 6-months there is only very little residue on the filter.

Had 1 of 4 arrive damaged, but a replacement was dispatched without a fuss. So far 2 are working well in a NorthBox filtration unit, and look forward to getting our second NorthBox running as well. Will update on filter performance once they’ve both had a chance to work away a while.

So happy for the convenience of getting these delivered and not having to search for your size and filter rating. Great product and price

I was very pleased with these filters although put them in upside down as the instructions were pretty much as guess for someone like me that ever had to replace a filter before, seems to be doing its job and for that I have to give it this rating. Very easy to install assuming one gets it rght side up.........lol