When Do I Need to Change My Filter?

Furnace filters come in many different types and it is very important to keep a clean and maintained system. How can you tell when you need to change your filter? When you notice that pet hair is prominent, dust bunnies are whirling around, and the general feel of the air isn’t as clean as it was before, it is time to change your furnace filter and purify the air in your home!

Your furnace filter traps dirt, dust, particles, and other airborne pollutants and is designed to stop them from getting into the heating system and damaging it. It is important to protect the heating coil and fan while maximizing your air quality. Your furnace filter is the critical mechanism to stop any allergens and bacteria from reaching the rest of your home. The easiest and fastest way to get the best efficiency from your furnace is to change its filter.

Take a look at the manufacturer’s maintenance manual and owners guide to determine the schedule that is best for your particular furnace. Besides their recommendations, there are some general rules to take note of to know when you need to change your furnace filter.

Normally, a furnace filter should be changed every month or two. This schedule is for basic, paper, or fiberglass filters. Measure the size of the filter. Smaller filters should be changed more frequently than larger filters because they have less space to trap dust and dirt. If your furnace has a HEPA filter, you should change it every two to four months.

Look for signs of excessive dust buildup, a heating fan that rarely stops running, or see that your current filter is obviously dirty. You’ll also know it’s time to change your furnace filter more frequently if there are smokers in the home, you generally keep windows and doors open (allergens get into the house this way), or you have pets and notice more hairballs than usual. Pet hair can quickly clog your air filters.

The best rule of thumb is that you need to change your filters when they are dirty! However, there are other, less subtle, determining factors that we haven’t covered yet that may require you to change your filter more frequently:

• If there is construction in your area (airborne dust particles can make their way to you)
• If there are several people in your home (rather than a single person, for instance)
• If you suffer from allergies

Conversely, if you’re maintaining a vacation home, or reside in a less-populated area, you can get away with changing your furnace filter less often; only once or twice per year. If you don’t have pets, the filter should be changed every three months.

Simply be aware of the performance of your furnace. Dirty filters will make the system run less efficiently and you know it’s time to change your filters. Replace filters with one of the same type and size. Refer to the manufacture instructions, user manual and safety stickers on the appliance to ensure maximum furnace safety.