Written by

10_17_13Choosing air filters for your Dallas home is about more than just the price. While air filters with a higher Minimum Efficiency Reporting Value (MERV) rating are more expensive than basic types, the cost is often worth it to enjoy better indoor air quality (IAQ). However, choosing an excessively efficient air filter can be a bad decision as well due to blocked airflow.

Here’s a look at different types of air filters, what they trap and which applications they are designed for.

• MERV 1-4: Filters at the lowest end of the efficiency spectrum come standard in HVAC systems. They capture the largest particles down to 10 microns, which includes dust mites, carpet fibers and pet dander that could damage the equipment. They provide very little improvement for IAQ.

• MERV 5-8: Mid-range filters are appropriate for most residential applications. They trap particles down to 3 microns, such as mold spores, hair spray, pudding mix and dusting aids. They provide reasonable improvements to IAQ at an affordable price.

• MERV 9-12: These higher-efficiency filters are only necessary if you have severe allergies or other respiratory problems. They trap particles down to 1 micron, including milled flour, auto emissions, humidifier dust and Legionella bacteria.

• MERV 13-16: The highest-efficiency air filters on the MERV scale trap particles down to 0.3 microns, such as tobacco smoke, all types of bacteria and germs found in a sneeze. Because they have a tendency to block airflow considerably, filters with this high rating are not appropriate for residential applications. They are reserved for use in hospitals, smoking lounges and commercial buildings with superior IAQ.

• MERV 17-20: These are considered High Efficiency Particular Air (HEPA) filters, capable of trapping more than 99 percent of particles less than 0.3 microns, including viruses, carbon dust and combustion smoke. These are certainly not designed for HVAC systems, but they can be found in vacuum cleaners and portable air cleaners.

To summarize, the best air filters for home use are between MERV 5 and 12, depending on your IAQ needs. To learn more, please contact Crawford Services today.

Our goal is to help educate our customers in North Texas about energy and home comfort issues (specific to HVAC systems).

Image courtesy of Shutterstock