The Ultimate Guide To Air Filter Sizes: The Choice Is Yours!

air filter sizes

There are many different reasons you may want air filters, whether it's for allergies, second-hand smoke, illnesses etc.

Because of that, and because they come in many forms and types, knowing exactly which one to choose can be confusing.

Compiling a list of pros and cons and then trawling the web for reviews, price comparisons and ratings doesn’t sound fun.

We've done the hard part for you and aim to answer queries and simplify the process to get you the perfect air filter and air filter sizes for you.

What is an Air Filter and How Do They Work?

As the name suggests, air filters do just that, filter air. These work by in taking the air, passing it through a cleaning mechanism and simply pumping out the clean air.

This process, unlike water, doesn't use chemicals to cleanse the air but instead filters out the bad stuff.

People, on average, spend most of their time indoors. Considering that and given the fact that pollution is typically two to five times higher than it is outdoors, it’s a wonder everyone doesn’t invest.

Whole house filters are the most efficient way to cleanse and purify air.

They get built into the duct work of a forced-air heating or central air-conditioning system turning them into air vent filters and filtering the entire house.

These need professional installation depending on your type of filter and come in four different types.

Types Of Filter

Whole house filters come in four different types, and the type of filter will indicate what size filters you'll need to replace them. 

To begin with, you'll need to understand what different types of air filters there are.

Flat Filters

These are ready to go air conditioning and heating systems which contribute to whole-house filtration through a thin filter vent. 

You should normally replace these every 1-2 months to optimize their function and prevent blockages.

These can range from $20-$60. A great product with great air filter ratings and feedback is Filtrete Clean Living Basic Dust Filter. It's available from Amazon and is Amazon's best seller. 

This product comes in multiple sizes so you'll easily find the one you need.

Extended Media Filters

These are an improved version of the Flat Filters. Stacking the thin filters provides more opportunities for catching dust and particles. 

Professional installation is necessary, costing about $600. 

However, as this option only needs replacing approximately once a year, costing around $50. 

You'll find yourself saving money in the long run in comparison to other air filter prices.

Electronic Air Cleaning

This works by using an electrical charge to clean the air. This process follows a kind of sorting mechanism. 

The electrical current disrupts stagnant dust and particles making them become electrically charged and pass through a filter, being caught by a metal plate with the opposite charge.

This needs professional installation and costs approx. $600-$1000. 

Electronic air cleaners are likely the easiest to maintain, only requiring cleaning every 6-12 months with soapy water meaning there's no monthly/yearly expenditure needed.

Ultraviolet (UV) Air Cleaners

These target mold, fungus, bacteria etc. Ultraviolet air cleaners are often installed as additions to an electronic system.

Extremely effective, this type is often used in hospital environments, which need rigorous contaminant filtration.

What Size Do I Need?

Now you know exactly what type of air filter you have or perhaps want, simply follow this link to see how to measure your filter. 

With this you'll know what air filter sizes you require.

Alternative Options

Also available as portable devices, this is great for those of you who don't have central air conditioning or heating. 

Coming in as the cheaper option, they can cost anything upwards from $40.

A great product, with great reviews and feedback, is the GermGuardian. An Amazon bestseller, this is a fantastic alternative option.


There are numerous benefits to air filters, to mention just a few, allergies, respiratory problems, asthma, prevention of inhalation of second-hand smoke, the spreading of common colds and flu etc.

With so many benefits and with the world in general becoming a more polluted environment, it's no longer viewed as a luxury and instead as a necessity.


Now you have all the details and all the pros and cons laid out with the prices compared, finding the perfect air filter and air filter size for your needs should be a breeze.

You can go forward knowing how your whole-house filtration system works and breath easily knowing the health benefits.