How to Choose an Air Filter

How to Choose an Air Filter

You may know that air filters serve an important purpose, but you may not know the details of that purpose. Yes, they filter the air, but your standard model is designed more to protect your HVAC equipment from dust and debris rather than remove allergens and pollutants from your indoor air. Having knowledge about the different types of air filters can help you select the right air filter for your needs.

Air filters for HVAC equipment

Standard air filters should be changed approximately every 3 months to best protect your expensive air conditioning and heating equipment.

Washable filters

The main advantage of washable filters is that they can be washed and reused. They do however, have a low MERV (Minimum Efficiency Reporting Value) rating, so they are better at filtering out large dust particles than things like pet dander, bacteria, or smoke. Also, because they are washable, maintaining them regularly is a must, if you don’t they can be a breeding ground for certain fungi and bacteria.

Fiberglass filters

These filters are not reusable and have a lower MERV rating, so you need to be diligent about changing them as often as the manufacturer recommends.

Air filters for allergies

If you or someone in your household suffers from allergies, you may want to use filters that are specifically designed to block out dust and outdoor allergens.

Pleated and polyester filters

Pleated filters are similar to fiberglass filters but are much denser and have a higher MERV rating. With regard to indoor irritants, standard fiberglass models filter out less than 10 percent, while the pleated/polyester models filter out around 85 percent.

HEPA filters

If you are a severe allergy sufferer, you may want to consider HEPA (High Efficiency Particulate Arrestance) filters. They remove over 99 percent of all irritants in the air, but they are also the most expensive. Generally, they are used only in hospitals or in homes with severe allergy sufferers because they are so dense they can actually restrict airflow to your HVAC system, potentially causing equipment damage.

Before installing a HEPA filter it’s a good idea to consult with a certified HVAC professional to make sure you’re getting the correct MERV rating and maximum airflow.