Non-filtered air contains various particles like dust, pet dander, smoke particles, etc. Not only are these particles not the best to breathe in, but also not good for the health of your HVAC system. To get rid of these airborne particles, HVAC systems have filters that collect the dust and various debris. As air moves through the HVAC system, the filter traps airborne debris before the conditioned air circulates back through the home.

What are the different types of air filters available?

Filters can be put into categories based on how they function, including basic disposable filters, higher-efficiency filtration options, reusable filters, and active air-cleaning systems.

Disposable Filters:

• Fiberglass filters:

These are the cheapest filters, which are typically 1 inch thick and flat. They only catch big particles like carpet fibers, lint, and dust bunnies. This filter provides basic protection of the system, but it will not provide the best air quality for the home due to how thin the filter is. 

• Pleated Filter:

Pleated filters are one of the most common filters in residential homes and are made of folded polyester/cotton. The folds are similar to an accordion to give the most surface area and, in turn, collect more debris than the basic fiberglass filter. This filter has better filtration, is affordable, and works best when changed regularly. Although this filter is most homeowners’ choice, it can also be too restrictive and not have the best airflow, especially if not changed every 3 months. 

• Media Pleated Filter:

These filters are thicker, high-efficiency filters that are typically 4-5 inches thick. Due to their thickness, there is more surface area with high filtration and less airflow restriction than a dense 1-inch pleated filter. These are good for better air quality and last longer, so fewer replacements. These need to be replaced every 6-12 months.

Higher-Efficiency Filtration Options:

• HEPA Filters

This filter captures extremely small particles like bacteria, smoke particles, and microscopic dust particles, but it is mainly used in medical environments. Although these collect the smallest debris, residential HVAC systems typically cannot handle them due to the high airflow resistance, which can restrict airflow, causing performance issues.

• Reusable Filters

Reusable filters are washable and environmentally friendly, but can reduce performance if not taken care of properly. They require a lot of maintenance and cleaning about every 1-3 months, but can save money in the long run when properly maintained.

• Electronic Air Cleaners

These are more advanced than the typical air filter. They work actively rather than passively, which can be more efficient. Although these are extremely efficient, they also need to be cleaned every 1 to 3 months to ensure they are working properly.

MERV Ratings Explained

MERV stands for Minimum Efficiency Reporting Value, which determines how small the particles can get caught, depending on how tightly woven the filter is. Air filter performance is measured through MERV ratings. The higher the MERV rating, the smaller the airborne particles the filter can catch. The lowest rating is a MERV 1-4, which catches particles like carpet fibers, lint, and dust bunnies. The next rating is a MERV 5-8, which is the standard residential. This catches dust, pollen, and mold spores. Then there is MERV 9-12, which is better filtration for catching finer dust, pet dander, and some smoke particles. MERV 13-16 is a very high filtration that catches bacteria and tiny particles, but this may restrict airflow in common systems.

How to Choose the Right Filter

The right filter has to be what's best for your system and household. The most important factor in choosing an air filter is your system. To find out the correct size, you can look at the size of the filter currently in the system or measure the filter slot. After finding out the size, you can choose which type of filter is best for your home by figuring out which MERV rating is best for your needs. To make sure that you have the correct filter, it is best to consult an HVAC professional by calling Environmental Air Systems. 

Signs You're Using the Wrong Filter

Using the wrong HVAC filter can cause a variety of issues with your system. Some signs to look out for are:

• Poor airflow from your vents
• Suddenly higher utility bills
•  A filter that is physically bent or collapsed
•  A filter that is dusty around the edges

It is extremely important to look out for these signs in order to have a properly functioning system. If the filter is too small for the system, there will be gaps where particles can get through and go back into your system, then eventually into your house. Since airflow flows through the least resistance, the system won't blow the air as hard, which could cause your system to run longer and overheat.

If the filter is too restrictive for the system, airflow can become limited, making your system try to push hard to get the air through the filter. The filter could also get pushed extremely hard and cause it to get sucked into the system, damaging the blower motor. Overall, it is extremely important to choose the right filter. If you are unsure about your filter size, you might want to consider consulting an HVAC professional at Environmental Air System.

How Often Should Filters Be Changed

There are multiple factors to consider when deciding when to change your filter. The most important consideration is the thickness of the filter, but you should also factor in things like how many occupants are in the house, if you own pets, allergies/asthma, etc. If any of these apply to your home, you may want to change out the filter more frequently.

Here are some general timelines based on your filter:

• Standard Fiberglass Filter (1”-3”): Change every 30 days.
• Pleated Filters (1”-3”): Change every 60 to 90 days.
• Media Pleated Filters (4”-5”): Change every 6 to 12 months.

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For more information about filters, visit our How Often Should You Change Your HVAC Filter blog!

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Need help with HVAC maintenance, or not sure if your system is running efficiently? We are here to help! Contact us today through our Contact Page or call (866) 339-4822 to schedule service or preventative maintenance.

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