Castle FIlters: A New 1 Year HVAC Filter | Free Shipping In The Continental USA!

Customer Testimonials

“When I read about the Castle HVAC Filters I was a little skeptical as I live in Arizona and our systems here run almost non stop from April until October but they said it would last a full year so I decided to try it. Our dry climate also makes for an unusual amount of dust so I change my filter almost every month during peak usage. I installed a Castle filter in my home in February. It worked great but as the louvers over the filter began to get dirty I got a little worried. I cleaned the louvers and removed the filter. I was very happy to see that no dust had passed through the filter to the back side. I continued to use it and repeated the process of wondering and checking.

After over 13 months of use I finally removed the filter. There was no sign of dust passing through. The back side was as clean as the day I installed it. I could sense no loss in cooling or increase in noise level that would make me think there was some restriction. I have a few rental properties and I have installed Castle filters in all of them. It is great peace of mind knowing that my system will not be ruined by a renter who will not change the filter. I am four months into my second filter on my own home and it is working great. Glad that there is a great product like this made in the USA that works and will save me money over the long haul.”

– Tom Miller


“Because of my white carpet and furniture, I have become an air filter fanatic. I have replaced my air filter every three months for years, with the best filter I could find. I was skeptical of a filter that could last one year. I tried the Castle Air Filter and immediately noticed the filter didn’t hit against the air intake frame while pulling in air. e air flows quietly through the filter with less strain on the air unit. e convenience of replacing only once a year is wonderful and my air is clean. e Castle Air Filter is the best filter I have ever used. I love my Castle Air Filter.”

– Christy Sharp


“Castle Filter are a little pricier than paper HVAC filters, but I think that is misleading because, with Castle Filters, you only have to change filters once a year. is makes the price not only competitive, but cheaper in the long run and the quality difference is immediately apparent when you open the box. Oh, and they save you in a REALLY important way, with Castle Filters you don’t have to go up and down on ladders four times a year! So the savings in effort and the increase in safety (let’s just say I am not made to go up and down ladders), makes it worth paying a little more for the filter on the front-end!

I am really super impressed. My equipment not only worked well for the year, but I honestly believe my HVAC system was under less strain using the Castle Air Filter because the backside of the filter was still TOTALLY clean. It was like the filter was still ready for more use! Bottom line, I am a believer in Castle Air Filters and they are all I will use from now on.”

– Joe Harrison