Home air filters delivered when it's time to change them

at a price you'll love + free shipping!
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Starting at $16. Cancel anytime.
How it Works
Select your air filters

Choose the exact number of air filters your home needs, in all the right sizes.

Set your schedule

You choose how often to change your home air filters. Shipping is always free.

Regular deliveries

Get your air filters delivered so you'll always know when its time to change them.

Skip a delivery or cancel anytime.

No long-term commitment. Pause, modify, or cancel your account anytime to fit your needs.

High quality home air filters in every size
You need it, we got it.

Over 66,000 sizes and counting
Custom sizes available
Thicknesses from 1" - 6" and accordion

Choose from 3 Premium Filtration Levels
Great for homeowners looking to catch some of the bigger annoyances, like dust and pollen particles.
MERV 8 rating
Dust Mites
Popular! Awesome for those needing to catch smaller particles like pet dander in addition to dust and mold. A 'must' for pet owners.
MERV 10 rating
Dust Mites
Skin Flakes
Pet Dander
Health Shield
Perfect for folks who want to catch all the particles they can, even some of the smallest ones like cooking oil and cigarette smoke.
MERV 13 rating
Dust Mites
Skin Flakes
Pet Dander
Cooking Oil
Virus Carriers
Enjoy The Benefits
Reduce wear on your HVAC

Changing your HVAC filters on-time is crucial for extending the life of your system. Prevent expensive repairs and keep your HVAC working smoothly.

Lower energy bills

Your HVAC doesn’t have to work as hard when your air filters are changed on time. Save as much as 15% on your heating and cooling bill.

Breathe easier

Fresh air filters keep your air crisp and clean all year round. Sign up for an air filter subscription once and never think about your air filters again.

Join Thousands of Happy Air Filter Subscribers
4.6 / 5
Based on 1,026 Reviews
Excellent - 4.7
Based on 985 Reviews
“It's a lifesaver to get filters sent every month and not have to schlep to the store and hope your filter size is in stock. Having it arrive at the door is also a good reminder to change it as often as you should be, I love Second Nature!”
“This is such a helpful service. There's so much on the ol' to-do list and it's easy to forget little maintenance things like changing the air filters. As someone with allergies/chronic sinus issues, I can't afford to go without regularly changing the filters. Second Nature keeps me on track!”
“We love our Second Nature filter subscription! I never have to remember what size fits the furnace or when I last changed it, and they’re great for people who have pets and allergies.”
“Set up the filter size and type, schedule delivery intervals and you can take that chore off your mind. install the new filter when it comes in. It doesn’t get any easier than that.”
“I have my odd size filters delivered every two months. What a convenience! I never have to go looking for them or remembering when was the last time I changed filters. Pays off when the HVAC guys tell us the units are in good working order especially being 17 years old.”
Air Filter FAQs
Why is it important to change air filters on-time every time?

Changing your air filters on-time is similar to getting an oil change for your car. The longer you wait between changes, the more damage you can do. It's a mandatory maintenance item to keep your heating and cooling unit working smoothly.  Replacing your HVAC air filters every few months is a small price to pay rather than replacing your HVAC for thousands of dollars! Read more about how dirty air filters can impact your HVAC system. Regular A/C filter changes also keep your indoor air clean by filtering out particles such a dust, dander, pollen, and even virus carriers.

For more, read our Complete Guide to Air Filters.

What is MERV? Which filtration level is best for me? 

The higher the MERV rating, the higher the air filtration capabilities. The MERV rating you choose can be dependent on multiple factors such as number of people and pets in your household, your family's needs, and your location. For example, if someone in your home suffers from allergies or asthma, our MERV 13 Health Shield air filter is perfect for you. Live alone and away from areas of smog or smoke pollution? Our MERV 8 Essential air filter covers all the basics. Have a pet or two? Our MERV 10 Essential+ air filter does a great job of covering the basics and catching loads of pet dander too.

Still not sure what to pick? See our full guide on which MERV rating to choose.

How do I know my air filter sizes? 

First, locate all of the air filters in your home. Look for vents, air registers, and air return grilles in your walls, ceilings, or floor. Air filters can also be located directly in your system, air handler, or furnace. See more about air filter locations in our blog post.

The easiest way to gather your air filter sizes is to look at your existing filters. On the outer frame of your current air filters, you will see at least one set of numbers. You may see two sets of numbers such as: 19 3/4 x 19 3/4 x 3/4 and 20x20x1. When buying your size, select the air filter size that is rounded up.

Don't have existing airfilters? You will need to measure your air return vents with a measuring tape. For more information, read our full blog post about how air filter sizing works.

Are pleated air filters bad for my system? 

NO! This is a myth. The only way a pleated air filter can cause trouble is if you fail to change the air filter on-time. (That's what makes our subscription so great!) Pleated HVAC filters capture small particles that can be harmful to you and your HVAC system. Fiberglass filters allow these pollutants to easily pass through and cycle back through the system into your home so that you breathe them in. Along the way, some particles can attach to the refrigerant coils. This buildup can lower system efficiencies, drive up power bills, or even worse—cause a catastrophic breakdown. Learn more about pleated air filters vs. fiberglass air filters.

How often should I change my home air filters? 

HVAC technicians recommend you change your air filter(s) at least every 3 months. However, this is also dependent on your needs and lifestyle. Those with allergies or asthma might experience more relief from changing HVAC air filters more often. Live near areas prone to smoke pollution and smog? Again, change the HVAC filters more often.

A common myth is that your A/C filters should be filthy when it's time to change them. FALSE. If your home air filter is dark grey/black or covered in fuzz, it's way past time to change them. With Second Nature, you can always skip a delivery or modify your delivery frequency anytime!

Ready to check air filters
off your to-do list forever? 
We have refrigerator water filters too!
Sign up today, save on future replacements, and keep your water fresh.

A Perfect Subscription

Changing your home air filter isn't hard. Remembering when to change your air filters is another story. With Second Nature, you can set it and forget it! No need to remember your air filter sizes or when you changed them last. As soon as you get your air filters delivered, you know its time for a change and you'll have everything you need.

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Why Second Nature?

We believe changing your air filters should be so easy it feels like second nature. When it comes to air filters, there's a surprising amount of information to absorb. We love this stuff, but we know not everyone cares! We've done our research so you don't have to.

Second Nature Perks

Always FREE shipping
66,000+ sizes & custom sizes
Choose any delivery frequency you prefer
Skip a delivery or cancel anytime
No membership fees
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Air Filters Delivered When It’s Time to Change Them

Change your air filters on time, every time. No hassles, just fresh air.

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The #1 air filter subscription trusted nationwide.

Hassle-free, automatic deliveries of the exact filters you need, right when you need ‘em.

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You'll Love the Benefits!

Time & Money Savings

Prevent costly repairs to your heating and cooling systems.

HVAC Protection

Reduce the energy usage of your HVAC system by up to 15%.

Healthier Living

Improve your home’s air quality by removing harmful toxins.

Our Air Filters

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