Types of Air Filters for Your Residential HVAC System

With spring in full bloom, now is the perfect time to check your air filter and replace it if you need a new one. Since you read about how often to change your air conditioner filter earlier this month, the professional HVAC contractors at Lenz Heating & Cooling want to help you find the right type of air filter for your Des Moines area home.

Energy Efficiency Standards

When it comes to indoor air quality, the American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE) established energy efficiency standards using a rating system called minimum efficiency reporting value (MERV). MERV uses a 1 to 16 rating scale, with inefficient HVAC filters having a lower rating and efficient air filters having a higher rating, based on the filter’s ability to remove large and small airborne particles. Keep in mind that air filters with a 16 MERV score may not always be the most practical for a residential air conditioner. If you’re a homeowner who wants the best dust control an air filter can provide, an HVAC filter with a MERV rating between 9 and 12 is the best solution.

HVAC Air Filter Types

Below are the most common air filters used in air conditioning units, ordered from least effective to most effective for improving indoor air quality.

Washable Air Filters

Washable air filters are not recommended for most residential HVAC systems. These filters usually run about $20 and require additional maintenance. Washable air filters are more susceptible to collecting fungus, bacteria, and other microorganisms that can escape from the filter and circulate throughout your home. The MERV rating for washable filters is usually between 1 and 4.

Fiberglass Air Filters

While extremely effective for protecting your a/c unit from large damaging particles, fiberglass air filters do not improve the air quality in your home. Fiberglass filters are the least expensive of air filter types, but they must be replaced more frequently. If improving indoor air quality is a priority for your home, especially if anyone in your family suffers from allergies, we recommend avoiding these types of filters. Fiberglass air filters are rated between 1 and 4 on the MERV scale.

Polyester and Pleated Air Filters

Polyester and pleated air filters are more effective at trapping dust and other small particles than fiberglass air filters, removing about 45 percent of air pollutants in your home. Pleated air filters have the added advantage of capturing more airborne particles without significantly restricting the airflow of your air conditioner. With a MERV rating of 8 to 13 and an average cost of $10, polyester and pleated air filters are an ideal solution for homeowners concerned about indoor air quality.

High-Efficiency Air Filters

These HVAC filters, including HEPA filters, are the most effective at removing pollutants from indoor air, but they are also the most expensive. Made from pleated filter paper or synthetic polyester fibers, high-efficiency filters remove 85 percent of airborne particles, including dust pollen, and mold. High-efficiency filters have a MERV rating between 14 and 16, but are not the best for home HVAC units. These filters are typical for industrial settings such as hospitals and other sterile environments.

 
Remember that your heating and cooling system does not need a filter with the highest MERV rating to be an effective solution for your indoor air quality needs. It’s also important to keep in mind that an air filter that heavily restricts airflow can cause your HVAC unit to malfunction, precipitating costly repairs or premature replacement. If you have any questions or concerns about choosing the right air filter for your home, call the professionals at Lenz Heating & Cooling; we’re happy to assist Des Moines, Johnston, West Des Moines, Winterset and the surrounding areas with all their HVAC needs!