Furnace Filters

PureFilters carries all types of furnace air filters and other HVAC filters that are suitable for all kinds of units and households.

PureFilters sources furnace filters from OEM brands across North America and we also manufacture our own brand as well.

There are many ways to find the exact furnace filter you need for your home on our website.  Below are some of the ways you can narrow down your search.

Browse by Filter Size

We have over 900 different sizes of furnace filters in our store, and narrowing down your exact filter size on our website is very easy. Be sure to read up on our Furnace Filter Sizes Guide in order to avoid costly mistakes and ensure you order the correct size filter for your furnace of HVAC unit. In order to search for your filter by size, please click on the link below.

Browse furnace filter sizes

Browse by Filter Brand

We carry several different type of OEM brands that are sourced directly from the brand manufacturer. Branded filters tend to be a bit pricier than aftermarket or compatible filters and offer no real increase in quality in comparison. PureFilters branded filters are manufactured here in Canada and offer a much better value compared to OEM equivalents. In order to search for your filter by brand, please click on the link below.

Browse furnace filter brands

Browse by Filter MERV Rating

You can also narrow down your filter by the MERV (minimum efficiency reporting value) rating you are looking for. If you are unfamiliar with which MERV rating you need for your home, check out our Furnace Filter MERV Rating Guide. In order to search for your filter by MERV rating, please click on the link below.

Browse furnace filter MERV ratings 

Browse by Furnace Filters by Model Number

Most OEM branded filters have a unique model number associated to them. You can easily search the brand and model number at the very top of our website by clicking the magnifying glass as seen here:

It's a good idea to search both the model number and the brand + model number. For example, a common furnace filter model is "Lennox X6670", so you could search both "X6670" and or "Lennox X6670" and you should be able to find your filter.

Request Custom Size Furnace Filter

If you still cannot find your furnace filter listed on our store, you can always request a custom size filter. Custom size filters can take up to 15 business days to deliver and all custom size filter sales are final (no refunds/exchanges). In order to request a custom size filter and receive a quote for your order, please click on the link below.

Request custom size filter

If you need help finding your exact filter on PureFilters.ca and prefer to speak to someone, please give us a call at 1-888-979-4284 or email us at support@purefilters.ca. We are available Monday to Friday from 9AM to 5PM Eastern Standard Time.

What are furnace filters?

Before we get into all the ways you can search for your furnace filter, it's good to get a background on what exactly furnace filters, what purpose they serve and the different type of furnace filters available in the market. We also want you to know why furnace filters are so important and why you should change them frequently.

First of all, the term "furnace filter" is interchangeable with "air filter", and "HVAC filter" and "furnace air filter". The are often inserted within the HVAC unit, such as a furnace or air conditioner, and their sole purpose is to trap particles in the air.

Filters are also found at within ductwork systems, filtering air that passes through an air vent and into a room. In both cases, the filter is designed to trap particles that may otherwise end up inside the HVAC system or floating around in a room.

Types of furnace filters

Fiberglass: this variety is the cheapest but least effective on the market. They protect you from dust and pollen, but leave smaller particles like smoke and bacteria untouched. These filters need to be replaced every month, and as a result, may end up costing you more over the long run.



Electrostatic furnace filters are made of pieces of vented metal that generate static electricity as air passes through them. The positive charge attracts larger particles like carpet and textile fibers, but will do little when it comes to anything as small as pollen or mold spores. In spite of the minimal protection, these filters need to be replaced every year and washed every month to make a difference.



Pleated: this variety is made from paper, cotton, or polyester, and is the standard in most homes. You can purchase disposable ones, which need to be replaced every three months, or permanent high-efficiency models that are good for anyone with respiratory issues. Pleated furnace filters can protect you from bacteria like Legionella and volatile organic compounds from household cleaning products.



HEPA or high-efficiency particulate air filters work by pushing air through a very fine mesh to trap over 99% of all particles as small as 0.3 microns. They’ll quickly take care of bacteria and viruses to prevent airborne disease, but are less effective when it comes to gases and odours. HEPA are commonly found in hospitals and clean rooms.

Why are so important?

Furnace filters within an HVAC system are very important because they protect the furnace and or air conditioner system from dust and other particles. If dust were to enter your HVAC unit, it could cause some serious damage and even pose a fire hazard if left unchecked. The dust will ultimately shorten the life of your HVAC unit and cost you a ton of money in the long run.

Another reason why furnace filters are so important is because they protect the air in your home from being contaminated with dust and other harmful pollutants. This is especially the case for the air filters found within the duct system or inside an air vent.

Poor indoor air quality is the leading cause of respiratory illnesses and can have harmful long-term consequences on your family's health and well-being.

Why should you change them frequently?

There are three main risks of not changing your furnace filter in a timely manner. The first has to do with indoor air quality, as mentioned above, a dirty filter can lead to poor indoor air quality and cause health problems and respiratory illnesses. By changing your filter frequently, you can ensure that the air inside your home stays fresh and free of harmful pollutants.

The next two issues have to do with your HVAC unit. Your furnace or air conditioner has to work hard to push air through a dirty filter and thus can significantly increase your energy bills. If left unchecked, a clogged filter can even blow up an HVAC unit, a malfunction that will cost several thousands of dollars to repair or replace. It's best to avoid both issues by changing your filter frequently and keeping the air flow through your filter as high as possible.

Each home has a different environment, and how often you need to change your filters depends on a variety of factors. This is why we created the Filter Change Frequency Guide.

PureFIlters, the leader in furnace filters, strives to raise awareness that many Canadians simply aren't changing their furnace filters often enough. Our mission is to make indoor air quality simple and affordable by providing high quality filters at fair prices, outstanding customer support and free express delivery.