What Happens If You Use The Wrong Size Air Filter

You’re shopping at your local home improvement store and suddenly you remember you need to grab a new air filter. You walk down the right aisle and browse through the selection the store has in stock.

Of course, they don’t have the size you usually use so you just grab something you think is close enough. A couple weeks later you notice the air quality in your home isn’t as great as usual.

If you’re wondering what happens when you use the wrong size air filter, your air quality isn’t the only thing you need to worry about!

Using The Wrong Size Air Filter

Using the wrong size air filter won’t damage your HVAC system, at least not immediately. It does have still have a major impact, though.

An incorrectly sized filter reduces the efficiency of your heating and cooling system. This can quickly add up and becomes more of an apparent issue that you’ll likely notice on your next utility bill. 

The biggest concern when you use the wrong size air filter is that it may not effectively prevent dust from building up on your HVAC system’s motors and blowers. This quickly dirties up your furnace which can affect its performance or possibly harm the system’s internal components, leading to more costly repairs or replacements down the line.

Filter Types

It’s important to remember that air filters vary greatly in terms of size, thickness, and material. Most filters are made of fiberglass, pleated paper, polyester fibers, and electrostatic pleats. Regardless of what type is best for your individual HVAC system, it’s important that you change or clean the air filter often. This will help you maintain healthy air quality within your home, while also ensuring your HVAC system is working efficiently and effectively.

MERV Ratings

It’s a common misconception that you should use an air filter with the highest possible MERV (Minimum Efficiency Reporting Value) rating.

This comes from the fact MERV ratings are based on how good air filters are actually filtering. The higher the MERV rating, the more particles the filter will catch. This sounds good, in theory, since no one wants particles floating around their home through their HVAC system. However, higher MERV ratings can also mean more resistance and less airflow overall through your home.

Not every HVAC system is designed to work with super-fine mesh filters. If your system isn’t compatible with the filter, you may be severely restricting air flow. This can lead to the same problems associated with choosing the wrong size air filter, including poor indoor air quality (since air is unable to circulate properly, including through the stronger filter you’ve selected), unnecessary wear and tear on your equipment, and inefficient energy use.

Not Sure If You’re Using The Right Size Filter?

If you have questions, give our HVAC team a call. We’ll work with you to ensure you’re using the right size air filter for your HVAC system.