A 1 inch air filter is the most common filter in American homes and for good reason. It slips into nearly every residential HVAC system without modification, costs less per filter, and keeps your air clean with a quick monthly swap. Aerterra's 1-inch air filters take that everyday essential and make it better: built from renewable, plant-based corn fiber, made in America, and delivered free to your door. Browse the full range of sizes and MERV ratings below.
Why a 1 inch air filter fits almost any home
If you've never measured your filter slot, odds are it takes a 1-inch panel. These slim filters account for the vast majority of residential systems installed over the last few decades, which is exactly why 1 inch air filters are the default choice for most households. There's no media cabinet to retrofit and no compatibility guesswork. Pull the old one out, slide the new one in, and you're done.
That universal fit is the 1-inch filter's biggest advantage. Whether you have a furnace, a central air conditioner, a heat pump, or a combined HVAC system, the same return slot handles all of it. Just 1 filter, working year-round to protect your equipment and your air.
1 inch furnace filters and AC filters in one
Because your heating and cooling share a single return, a 1 inch furnace filter does double duty as your air conditioner filter too. In winter it shields your furnace's blower and heat exchanger from dust buildup; in summer it does the same job for your AC coil. A clean furnace air filter keeps airflow strong, helps your system run efficiently, and stops dust, pollen and pet hair from recirculating through your rooms.
Aerterra's 1 inch furnace filters and AC filters are designed to compare directly with familiar names like Honeywell and Filtrete, so switching over is effortless, same fit, cleaner materials, better story behind them.
Find your size
This collection covers the most-requested 1-inch dimensions, including 12x12, 12x24, 14x20, 14x25, 16x20, 16x25, 20x20, 20x24, 20x25 and 24x24. Your size is printed on the cardboard edge of your current filter, listed as width x height x depth. Read it, match it, and you're set. Don't see your exact size in our 1-inch air filters lineup? Use the custom-size request button on this page and we'll send you a quote.
MERV 8, 11 or 13: choosing the right 1 inch HVAC filter
Every 1 inch HVAC filter here carries a MERV rating that tells you how fine its filtration reaches. Pick based on who lives in your home and how sensitive they are to air quality:
- MERV 8 — solid everyday filtration for dust, lint, pollen and mold spores. A great baseline for homes without allergy concerns.
- MERV 11 — steps up to capture finer particles like pet dander and smoke, ideal for pet owners and lighter allergy sufferers.
- MERV 13 — our highest 1-inch tier, trapping the smallest particles including fine smoke and many airborne irritants, for homes that want maximum filtration.
Because a 1-inch panel has less surface area than a thicker filter, a higher MERV rating will load up a little faster — that's the natural trade-off for finer filtration in a slim profile, and an easy one to manage with a regular swap schedule.
Renewable filters, made in America
Most air filters are plastic. Ours aren't. Aerterra builds these 1-inch air filters from USDA-grown corn fiber enhanced with nanofiber technology, capturing microscopic pollutants, allergens, fine dust and airborne toxins, without the petroleum-based frame and media that pile up in landfills. They're manufactured in the USA and backed by free shipping and a money-back guarantee. You can also explore the full range of air filters HVAC systems rely on across every size and depth we make.
How often should you replace a 1 inch filter?
For a 1-inch filter, plan to swap it every 1 to 3 months. Homes with shedding pets, smokers or heavy dust trend toward monthly; quieter, low-traffic homes can stretch closer to three. Running your system on a clogged filter forces the blower to work harder, raises energy use, and lets dust slip back into your air, so staying on schedule genuinely matters. Prefer not to track it yourself? Our subscription delivers a fresh filter to your door right when it's due, so you never run a swap late again.
1-inch vs 4-inch: which is right for you?
The 1-inch filter wins on fit, price and simplicity; it works in virtually every system and costs less per filter. If your equipment happens to have a deeper slot or media cabinet, a 4 inch air filter lasts longer between changes and offers stronger airflow over time. Not sure which one your system takes? Our 1-inch vs 4-inch air filter guide walks through compatibility, cost and lifespan in plain language so you can choose with confidence.
Shop the collection
Ready for cleaner air? Browse all 1-inch air filters below from MERV 8 everyday essentials to our highest-filtration MERV 13 each one renewable, free-shipped, and backed by our money-back guarantee. When it comes to your home's air filter, the smartest upgrade is often the one that fits right the very first time.
Frequently asked questions
Will a 1 inch filter fit my system?
Almost certainly. 1-inch filters fit the vast majority of residential furnaces, air conditioners and heat pumps. Check the size printed on your current filter and order a match.
How do I find the right 1 inch air filter size?
Read the dimensions on the cardboard edge of your existing filter width x height x depth (for example, 20x25x1) and order the same size.
What MERV rating should I choose for a 1 inch HVAC filter?
MERV 8 covers everyday dust and pollen, MERV 11 adds pet dander and smoke, and MERV 13 delivers the finest filtration for allergy-sensitive homes.
How often should I replace a 1 inch furnace filter?
Every 1 to 3 months. Pets, smoking and heavy household dust push you toward the shorter end of that range.
Are 1 inch air filters good for allergies?
Yes, choose MERV 11 or MERV 13 for stronger capture of fine allergens like pollen and pet dander while keeping airflow healthy.
What are Aerterra 1 inch air filters made of?
Renewable, USDA-grown corn fiber enhanced with nanofiber technology, made in the USA, not petroleum-based plastic.
Do you ship for free?
Yes. Every order ships free within the U.S., comes with a money-back guarantee, and includes an optional subscription so you never forget a swap.
