If you do nothing else to care for your furnace, you should at the very least replace the furnace filter on a regular basis. Some people get lucky and the only negative consequences of furnace neglect are poor air quality and low efficiency, but failing to replace the filter regularly could potentially choke the life out of your furnace. Chances are you don’t want any of these problems in your home, so now is the time to give your furnace and the air in your home a little TLC by replacing the air filter. But, how do you know which one to choose?
Look for a MERV Rating
MERV ratings make it easier to choose the perfect filter for your furnace. A MERV rating is a measurement of the filters ability to remove particles from the air down to a specific micron. A micron is extremely small. 1 micron is equal to 1/25,000 of an inch, and the human eye can only see down to 10 microns. We would need a microscope to see anything smaller. The smaller the particles that a filter can capture the higher the MERV rating that filter receives on a scale from 1 to 16.
You may immediately jump to the conclusion that you need to run out and buy a filter with a MERV 16 rating, but that is not necessarily true. One of the key problems with filters is their ability to become clogged with debris and cause problems with the furnace. The thicker the filter is the more particles it will be able to catch, but that also means that is will restrict airflow more and become clogged sooner. For instance, a MERV 14 filter is very good at collecting particles, but unless it is religiously changed monthly, you are bound to have a problem with airflow.
Too Little Protection
Many homes use fiberglass panel filters. They are cheap, easy to change, and disposable, but they also only carry a MERV rating between 1 and 4. That basically means that it can only capture particles that you would be able to see. Unfortunately, the smaller the particle, the more harmful it is to our bodies. Most of the particles that cause harmful affects upon indoor air quality are smaller than 3 microns. So, a filter that can’t eliminate any of the particles we can’t see is not a good choice for you and your family.
Perfect Protection for the Majority
For many people, remembering to change the filter monthly just isn’t something that happens. We get caught up in our busy day to day lives and suddenly 3 months have gone by without a filter change. Luckily, there are filters out there that can accommodate these types of people, and let’s be honest most of us are these people. Choose a filter with a MERV rating between 5 and 8. These filters are usually media filters. This type of filter is nice because they can often last up to 3 months without needing to be changed. Electrostatic filters don’t fall into the MERV rating system, but they are also a good choice for this type of person because many can be reused over and over with a simple washing every 2 to 3 months.
Intense Protection
For a more powerful and high maintenance filter, choose one that has a MERV rating between 9 and 16. Filters in the 9-12 range can collect particles from 1 to 3 microns. These are good if you are picky about dust lingering in your home, and it will capture most of the contaminants that affect poor air quality. If you go into the 13 to 16 range, you are choosing a filter that is on par with the types of filters that are used in hospitals, and it can capture down to .3 microns. If there is someone in the home with severe allergies or asthma or who has a compromised immune system, this would be the perfect filter to give them some relief from their symptoms and protect them from future illness. However, with these types of filters you must be very good about replacement. They will fill up quickly with particles and need to be replaced monthly without question.
It’s not too late too late to start caring for your furnace. Changing the filter today can make a drastic improvement in the overall air quality in your home in a matter of days.
