As a Smylie One Residential Comfort Consultant, I visit with many people in a variety of different homes. During those visits, I often times pull out the existing paper filter to find that it is nearly completely blocked with dust, dirt, pet dander, etc. At this point, the customer will pose the question of, “How often should I change that thing?” or, “Is that the right type of filter for my house?” These are both valid questions which typically require more than a simple one or two word answer.
What is the purpose of a filter?
Replacing the furnace air filter is one of the most basic and inexpensive things you can do to keep your system working properly and optimally. To use an analogy, the purpose for having a filter is similar to a person’s respiratory system. This may not make any sense right now, but stay with me and it will become clear. A basic necessity of life is to breathe in and out. Each of us has small hairs in our noses which are there to capture dust particles so that they don’t get into our lungs. Your furnace filter does the same thing for your furnace; it traps all kinds of particles before they get a chance to reach and cause damage to the furnace.
Another way that the air filter is similar to our breathing has to do with air flow. I want you to stop what you are doing right now and take in a deep breath. Now let the air out. Now take in a short shallow breath and release it. Did you notice that when you took in the deep breath that you were then able to release a lot of air at a strong velocity, and when you did the same with the shallow breath that the air you let out was a very small amount that could hardly even be noticed? In other words, the amount of air you take in is the same amount that you can put out. The same principal applies to the way your air filter works with your furnace and the air flow of your house. When the filter is clean, all the air that returns to your furnace is able to travel, unobstructed, back to the furnace and then into the living space. When the filter is blocked, the return air is restricted back to the furnace. This means that less air is going to flow back into the living space, and the air that does get through will come forth with less force. A clogged filter affects your air flow in much the same way that a cold affects your breathing
How often should I replace that thing?
The frequency of changing your air filter has to do with the type of filter you have and variables within the living space. For example, a 4” pleated filter is going to capture more particulates and be more effective than an inexpensive 1” filter. Also, if you have pets or live in an area that experiences lots of dust being blown around, you will most likely need to change your filter more often than a home where these conditions do not exist. Typically, the cheap 1” filters should be replaced once a month. The better, 4” filters may last for up to a year, depending on the conditions discussed above. To err on the side of caution, the best thing you can do is to have a Smylie One representative perform a tune-up and safety inspection on your heating and/or cooling system so that he can advise you on the type of filter you have, and to make recommendations for replacing it. Remember, if your furnace can’t get air, it can’t provide the house with air.