Not all air filters are created equal.
In fact, the differences between air filters can sometimes be so dramatic that it makes you wonder if we should consider them in the same category at all. Some air filters are 95 percent effective, and others are 95 percent ineffective, only removing five percent of the very largest particles from the air. And unfortunately large particles are less of a concern than the smallest particles in the air, such as bacteria, mold spores, and pollen.
On the surface, though, a high-quality air filter might not look very different from a low-quality filter. So how can you know what you are purchasing? The key is to look at MERV ratings.
MERV, or Minimum Efficiency Reporting Value, is a scale used to rate the effectiveness of different air filters. It is called a “minimum” value because it measures performance in a worst-case scenario; you can be assured that a filter will work at least as well as its MERV rating indicates, if not better. The scale ranges from one to 20, with higher numbers indicating higher effectiveness.
That doesn’t mean you should run out and buy a filter with a MERV rating of 20. In fact, you will have a hard time finding filters rated above 16, which is considered clean enough for surgical hospital settings. The downside of filters with exceptionally high MERV ratings is that air tends to have a harder time flowing through such a dense filter. To keep from impeding airflow, you need to have an HVAC professional design a system that can work with these air filters. Or you could choose to go with an air filter that has a mid-range MERV rating, probably in the seven to 13 range. Since the air in a home is circulated through the HVAC system and filter time and time again, mid-range air filters still end up being quite effective.
For a professional opinion on the air filters that will work best for your Tucson-area home, contact us at Rite-Way Ventilating Co. We have over 50 years of experience in helping Southern Arizona families stay comfortable and breathe easier, and we would be happy to help you do the same.
Our goal is to help educate our customers about energy and home comfort issues (specific to HVAC systems). For more information, click here to download our free Home Comfort Resource guide.