clock menu more-arrow no yes

Second Nature Air Filter Review 2021

Clogged air filters can lead to HVAC issues and cause respiratory problems if they aren’t replaced. Second Nature sends customers high-quality air filters of all different sizes as part of a convenient subscription service. Read our review to learn more.

Ceiling vent Adobe

Table of Contents

  • What Is Second Nature?
  • How Does Second Nature Work?
  • How Much Does Second Nature Cost?
  • How Does My Subscription Work?
  • Customer Reviews
  • Conclusion
  • Frequently Asked Questions

What Is Second Nature?

Second Nature, formerly known as Filter Easy, is an air filter subscription service that delivers air filters directly to your door. The company offers a wide variety of high-quality, pleated air filters of different sizes and thicknesses and also provides customizable filter options. All prospective customers can go through a free trial, where the first shipment of air filters is completely free.

Second Nature Pros & Cons

Pros Cons
Pros Cons
Always free shipping Limited to one filter quality per subscription
Provides customizable filter sizes and a custom shipping schedule Also sells filters from other brands
Customers can select the number of filters their home requires in one shipment and choose a specific initial ship date

How Does Second Nature Work?

Second Nature allows customers to select from more than 66,000 available filter options online. For your initial order, you’ll follow a five-step process and select answers to each question asked. Here are a few factors to consider before placing your Second Nature order.


You can select the exact number of filters in your home when placing an order.

Filter Dimensions

With Second Nature, you can select from a wide range of filters that have different thicknesses, including custom sizes. It carries more than 66,000 available filter options online. If you don’t see your exact filter dimensions on the drop-down list, you can enter in the dimensions yourself. There’s also a “Find My Filter Sizes” button that shows you how to identify the dimensions on your existing filters.

Note: You can select filters of different sizes for the same order. If you have two air filters that are 12 x 12 x 1 and two that are 18 x 18 x 1, you can specify this and order them in the same package.

By playing around with the sizing options, we discovered that Second Nature also sells air filters made by other companies, like Honeywell and Glasfloss. This information can only be found if you select, “All 4” and 5” thick filters.” Once you do this, you’ll be directed to select air filters by brand and model number.

Filter Quality

Second Nature offers three different levels of filters: MERV 8, MERV 11, and MERV 13. The filters differ in what they filter out and their price point. Minimum Efficiency Reporting Value, or MERV, is the system that evaluates how efficient an air filter is based on how effective it is at trapping different-sized particles. A higher MERV rating correlates to a higher-capability filter.


Minimum Efficiency Reporting Value MERV 8 MERV 11 MERV 13
Minimum Efficiency Reporting Value MERV 8 MERV 11 MERV 13
Filters Out Pollen, dust, mold, dust mites, and bacteria Pollen, dust, mold, dust mites, bacteria, and pet dander Pollen, dust, mold, dust mites, bacteria, pet dander, smog, smoke, cooking oil, and virus carriers

For example, you cannot choose for two out of the four filters to be MERV 8 and the remaining two to be MERV 13.

Shipping Frequency

You can choose to have filters shipped to you every month, every two months, or every three months, or you can set a custom shipping schedule. The custom schedule setting allows you to select the exact months you want your filters to arrive.

Second Nature suggests that air filters be replaced every three months to make sure your heating and cooling system runs well. The company also recommends that you replace your air filters every month if you have asthma or allergies, live in a highly polluted area, live in a very cold climate, or have multiple pets. Alternatively, you can replace your filters every two months if you have one filter in your home, use your heating and cooling year-round, or own a pet.

According to Second Nature’s Help section, you can set up different schedules for different filters. Simply go to your account and select “add subscription” to your profile and enter the schedule details.

Note: You can select the exact date you want your first shipment to arrive and Second Nature will charge you only once your order has been generated.

How Much Does Second Nature Cost?

For all new customers, the free trial includes one free shipment of air filters. After that, you’ll be charged for the filters you select based on the frequency of shipping. Shipping is always free. Since Second Nature offers several options for your home’s specific needs, exact pricing ranges from $10–$26 per filter with special pricing for custom sizes and thicker filters.

Note: There are no membership fees or commitments that you pay outside of the cost of the air filters.

How Does My Subscription Work?

When you sign up for your Second Nature subscription, you’ll set up an account where you can manage and edit your details. You can delay any upcoming shipments or cancel your subscription with no penalty. According to Second Nature, you can resume or reactivate your account with one click whenever you’re ready.

Customer Reviews

Second Nature is not accredited by the Better Business Bureau (BBB), but it holds an A+ rating from the organization. The company also has 4.5 stars out of more than 100 customer reviews. Here are a few Second Nature reviews left by customers:

“I’ve been getting their HVAC filters for a while now with no issues. I recently decided to start getting fridge filters and initially received the wrong one. After contacting customer service they responded right away and took care of it at no extra cost to me. The new filter actually fits better than the ones we had been buying. Great company!” — Dave

“I have never once received my filter on time. This service is supposed to be where you never have to think about your air filters, but each month my partner and I have to think about it. We have had to look up the tracking only to find that it has not been shipped (again)... This month, it was due a week ago and I have been charged, but it has yet to leave their facility. They created a tracking number, but FedEx says it has not been handed over to them yet. Did they do that just to appease me? Why is it so hard to send a filter that arrives at my door every 30 days? I am canceling and trying an alternative to see if it is reliable.” — Heather R.


You need to change your filters several times each year, but it’s hard to always remember when to replace them or what your sizes are. Second Nature’s service makes it easy to stay on top of this chore. Second Nature offers high-quality air filters in a variety of sizes. We like that Second Nature offers a free trial for new customers.

We also like that customers can customize when their air filters arrive and that shipping is free. This service is also convenient for customers who need to order several different-sized filters in one order. One downside to Second Nature is that customers can’t order several different qualities of filters per order.

Frequently Asked Questions

How much does Second Nature cost?

Second Nature air filter pricing ranges from $10–$26 per filter with special pricing for custom sizes and thicker filters.

Can I use two air filters in my HVAC system?

It’s not a good idea to stack two air filters against each other. While you may think this will prevent you from having to replace your filters as often, using two filters can raise your utility bill and lower your HVAC’s lifespan by upsetting the airflow in your home.

How often should I change my air filter?

Second Nature recommends that you replace your air filters at least every three months for the health of your heating and cooling system. You may need to replace them every month if you have asthma or allergies, or every two months if you have just one filter in your home.

To share feedback or ask a question about this article, send a note to our Reviews Team at