What Is A Furnace Air Filter And How Does It Work?

Furnace Air Filter

Published on June 5th, 2020

If you live in a place where the seasons constantly change, then you are definitely familiar with the importance of a furnace.

This keeps you warm during the winter months and cools in the summer. For this reason, you need to keep it in tip-top condition, whether it involves changing the filter type from disposable to reusable or replacing the filter size based on the system, such as an 8x24x1 or a 16x25x1 air filter.

It might sound simple at first, but maintaining your furnace by changing the air filters is not an easy task. One wrong choice can do more damage to your furnace and can even lead to its breakdown.

How A Furnace Works

Most furnaces work by drawing in air through the return ducts and warming it over a heat exchanger.

After that, heated air is pushed through a series of ducts with the help of a blower fan. These then branch out into different parts of the building.

What Is A Furnace Filter?

A furnace filter is used to help protect the unit from damage. It is utilized as protection from all the dust, dirt, and other microscopic organisms that might accumulate in the blower fan. It substantially improves indoor air quality.

That is why regular maintenance of it is needed to avoid health issues and even repair problems of the actual unit itself. Should the dirt and dust build-up, it might lead to more costly repairs.

The MERV Rating

Furnace filters are rated using the MERV or Minimum Efficiency Reporting Value. It ranges from 1 to 16. The higher the MERV rating of your furnace filter, the finer particles it can eliminate.

This is because these filters will allow less airflow and will force your furnace to work harder.

The recommended MERV ratings for your home are between 8 to 11. It is also best to remember the maximum MERV rating that your furnace model can use.

The Different Filter Types

There are different kinds of furnace filters. One of the most common ones would be the disposable pleated furnace filter. These are made out of paper and polyester.

They are preferable for homes since they do a great job of filtering household particles and allergens. Another type is the disposable fiberglass furnace filter.

This is considered as the cheapest filter, and it has an almost spider-web like appearance. It has lower ratings than the pleated filters because of its inferior quality. Other types of furnace filters include permanent reusable furnace filters.

These are washable and are made with either a plastic frame or solid aluminum.

These are more efficient since they can be vacuumed or cleaned with water. They also have an average lifespan of at least 5 years if properly maintained.

The Different Filter Sizes

All furnace filters come in different sizes. This is to be able to accommodate all kinds of furnace models.

They differ in thickness, height, and length. That is why it is crucial for you to choose the right furnace size.

The most common sizes are the 16x25x1 air filters, the 30x30x1 ones, and the 20x25x1 filters.

If you want to know your furnace’s filter size, remove and check the old filter since the size is usually written on the frame. You can go through your furnace manual as well.

After understanding a furnace filter and its benefits, you should change or replace your old 20x25x1 or 16x25x1 air filter as it will affect your furnace and the quality of air you breathe. Make sure you get the appropriate furnace filter while buying a replacement.