Shop Furnace and AC Filters - Trusted Filtration Retailer Since 2006

Over a million filters sold and replaced. That’s billions of particles removed from indoor air. Trust your air to us. RTF has been In business for 14+ years and is a preferred online retailer for AAF Flanders Furnace and AC Filters

Featured Filters

View all

Quality Furnace and AC Filters

What’s your need? Commercial? Residential? Industrial? HEPA? We have you covered! At, you’ll find the perfect filter for your HVAC system -- by a leading manufacturer!

Buying filters online at is easy, convenient, and saves you time and money. No high-pressure sales. No time-consuming service appointments. No searching for weeks or months for your filter size. Just friendly, knowledgeable filter experts dedicated to helping you select the right filters for your system.

With thousands of sizes to choose from, you’ll never have to search for your filter again! You can even buy custom furnace and ac filters online! We’ll send you perfect fit filters for your HVAC system. We deliver filters to you for free, too! Whether you live here with us in the Pacific Northwest, or you’re in Texas, Chicago, New York, Los Angeles, or Florida, we deliver for free anywhere in the entire contiguous United States – even oversized or special order filters.

Our Filters

Blog posts

View all

System specific question - non filter related

Since all homes and systems are different it's really hard for us to help answer your question without seeing your system design, layout, etc. It s...

How can a filter help allergies and asthma?

It is nearly impossible to eliminate the sources of pollen allergens and dust mites, so your best course of action in eliminating the threat of the...

How do I know what kind of filter I need?

With so many options it can be overwhelming trying to decide what filter best suites your needs. Panel (basic) filters, usually 1" fiberglass filte...