How to Know When to Change Your Furnace Filter

By: Katarina Knoff

It is easy to forget about changing out your furnace filters because let’s face it- when it is out of sight, it is out of mind. However, changing out your furnace filter is a very important task to remember. It helps you keep your energy costs down, maintains a healthy air quality, extends the life of your HVAC system and keeps your heating and cooling systems clean. There is no rule on when it is time to change out your furnace filter, but there are some guidelines that will help you stay on top of it, save you money and keep a healthy home. Today we will cover some of those guidelines, signs to look for to indicate the need for a change and other factors to keep your HVAC system running smoothly.

When to Change Furnace Filters:

In general, it is suggested to replace

  • One to two-inch filters every three months
  • Four-inch filters every six months 
  • Five-inch filters every 12 months

There are some things to keep your eye on that will help indicate when it is time to change the filter. 

Signs to Look Out For:

· When the filter is visibly dirty (If you can’t see the grid of the filter, it is time to replace!)

· The heating and cooling systems are running more frequently than normal.

· You realize dust is accumulating too quickly in your home. 

· You notice burning smell or other strange smells near your HVAC unit.

Although this is a rule of thumb, other factors can increase the frequency that a filter needs changing. 

Factors That May Increase the Need for Replacing a Filter:

·      Frequently opening windows and doors

When you let outside air flow freely into your home, you are also allowing contaminants to enter. These can leave a layer of dirt inside of your air filters. If you are a person who often leaves doors and windows open, you might find yourself changing filters more often. One and two-inch filters will need to be replaced monthly, four-inch filters every two months and five-inch filters every three months.

·      Having Animals 

If you own any furry pets, your filters will have a shorter lifespan. If you have one pet, it is recommended that you change your filter every two months for a one or two-inch filter, four months for a four-inch filter and six months for a five-inch filter.

·      Smokers

If there are any smokers in the home, the smoke will dirty up those air filters quickly. For one smoker in the house, you can get away with changing out a one or two-inch filter every two months, a four-inch filter every four months and a five-inch filter every six months. Any more than that and you will need to adjust those numbers even more. 

Leave a Reply