Most southwest Illinois residents understand the benefits of A/Cs and furnaces in controlling air temperature in homes, apartments and businesses but not everybody realizes the positive effect that air filters can have on indoor air quality. Even those that do may be unsure which air filters to purchase when it comes time for replacing a dirty filter.
Air filters have a Minimum Efficiency Reporting Value, or MERV, which is a rating scale developed by the American Society of Heating, Refrigerating and Air Conditioning Engineers. On a scale of 1 to 20, the MERV rating determines the size of airborne pollutants captured by a particular filter.
For instance, a filter with a MERV rating of 1 will filter out large particles such as carpet fibers but be ineffective at removing mold spores, which require at least a MERV rating of 7. Pollen and dust mites can be stopped by filters at level 4; not until a rating of 14 will a filter protect from tobacco smoke. While it may sound like common sense to install only the highest MERV-rated air filters, it’s important to realize the more “efficient” a filter, the more resistant it is to airflow. For typical Illinois residents, the sweet spot for filtration without undue load on household heating and cooling equipment is between 6 and 12. Only places such as research and hospital cleanrooms require a MERV rating of 20, and most standard HVAC equipment is the wrong size or simply isn’t powerful enough to move air through such intense filtration.
In fact, the gold standard of HVAC filtration, high efficiency particulate air, or HEPA, filters, aren’t typically useful in most home setups. If you feel air quality in your home needs the highest-possible filtration, consider aiming for the sweet spot and incorporating other air quality control steps in your home instead of overwhelming (and possibly damaging) your HVAC equipment.
For over half a century, Ernst Heating & Cooling has been providing professional support and services for southwest Illinois communities, from Alton to Collinsville to Greenville, as well as the surrounding areas. Contact us today to learn more about air filters or to receive assistance from HVAC professionals.
Our goal is to help educate our customers in Hamel, Alton, Glen Carbon, Highland, Greenville, and Troy, Illinois and surrounding areas about energy and home comfort issues (specific to HVAC systems).
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