MERV: What to Look For When You’re Replacing Air Filters

Minimum efficiency reporting value (MERV) indicates an HVAC filter’s efficiency at trapping dust and other airborne particles. The values range from one to 20. The higher the MERV, the more efficient the air filter. If you’re choosing a new air filter for your Delaware area home, understanding this evaluation system will help you find the best filter for your needs.

• Values 1 to 4 – Filters in this range are usually the cheap fiberglass or paper panels that are standard for all HVAC systems. They’re designed only to keep dust and debris out of your system, not to clean your air. They capture a minimal amount of larger particles, such as dust, pollen and carpet fibers.
• Values 5 to 8 – These are usually pleated (extended-surface) filters made of synthetic fibers or paper. Filters in this range moderately improve your air quality. They can trap most particles down to 3.0 microns, which includes mold spores, larger bacteria and even airborne particles from household chemicals. These filters are sufficient as long as no one in the household has allergies or asthma.
• Values 9 to 12 – Pleated filters in this range can capture most airborne particles down to 1.0 micron. The above-average air filtration they provide may be helpful for reducing allergy and asthma symptoms.
  Values 13 to 16 – These filters provide the highest level of filtration you’ll find in residential HVAC air filters. They can capture particles down to 0.3 microns, which includes smaller bacteria and tobacco smoke particles.

Before upgrading from a basic fiberglass panel to a filter with a MERV of 5 or higher, consult with an HVAC technician. Higher-efficiency filters may slow down airflow enough to have a detrimental effect on your system. In some cases, a technician can adjust your blower fan’s speed to prevent problems from reduced airflow.

For answers to your questions about improving your indoor air quality or selecting HVAC supplies, contact us at Sobieski Services. Our goal is to help educate our customers in Delaware, Pennsylvania, Maryland and New Jersey about energy and home comfort issues (specific to HVAC & plumbing systems).

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