This is not an easy question to answer because there are too many variables to consider. The make, model, and type of furnace that you have installed in your home is certainly a key factor. But, people tend to use their furnaces for different temperatures and times, and the frequency of use is also an important factor. So, there is no one-size-fits-all answer, but there are certain guidelines that can help you to make an informed decision. In this article, we will take a closer look at the frequency of furnace filter changes.

A Brief Primer on Furnace Filters

Furnace filters are relatively inexpensive, but they are a critical component and their importance should not be underestimated. A clogged air filter can cause a lot of problems, including a lack of performance, poor indoor air quality (IAQ), component failure, carbon monoxide leaks, poor energy efficiency, and more. So, it’s important to take furnace filter replacements seriously, and if you can’t remember the last change, go ahead and do it now.

How Often Should I Change the Furnace Filter?

As we mentioned in the introduction, there is no hard and fast rule, but there are some benchmarks to consider for your home. As a rule of thumb, a 1”-2” furnace filter change should occur every three months. If your furnace uses 4” filters this period rises to every six months. If you’re using 5” furnace filters, you may be OK with an annual filter change. These are useful benchmarks, but you may want to periodically check the furnace air filter condition for signs that it needs to be changed.

4 Signs That Your Furnace Filter Needs Changing

Let’s take a more detailed look at four signs that you should consider changing the furnace filter at an earlier than expected time:

  1. The Filter is Very Dirty: If you examine the furnace filter and you cannot see the filter membrane material, it’s time to replace it.
  2. Excessive Dust Levels: If you notice that your home is extra dusty this often indicates that the dust is escaping the furnace filter and it’s being recycled into your home.
  3. The HVAC System Runs Frequently: If the system is running more frequently than normal to bring the home to the temperature set on the thermostat, this may indicate that the filter is clogged.
  4. Strange Odors: If you notice strange odors or a burning smell, it’s time to change the furnace filter. If the odor persists, contact your local HVAC specialist to check it out for you.

How to Change the Furnace Air Filter

A full guide on the exact process is not possible because there are differences between the various makes and models on the market. But, regular filter changes are necessary to keep the system clear of dust and other contaminants that can cause problems. When the air filter is clogged, there may be IAQ issues that are usually detected by people with allergies and pre-existing respiratory ailments first.

The best place to check which furnace filter you need, where it’s located, and how to change it is in the owner’s manual. If you’ve misplaced your manual, check the manufacturer’s website to get a free pdf copy that contains valuable information. Changing the air filter requires no special skills or tools, and it takes moments to finish the task. Take care to use the right filter, the number is printed on the filter rim, and it should match the needs of your HVAC system. If the filter is too large, it won’t fit, and if it’s too small, contaminants will pass around it.

How to Improve the Indoor Air Quality (IAQ)

A standard furnace filter will make a minor improvement to the IAQ, but it’s not a replacement for an air purifier, HEPA filter, or other dedicated air cleaning system. It may be possible to install these systems in your existing HVAC system, but this is not always possible. But, if you want to improve the IAQ now, the best approach is to boost the oxygen levels in your home. The doors and windows should be opened for an hour or two if weather permits, and adding some house plants can help. The aforementioned furnace filter change frequency times will make a difference if you remember to change them.

What About Pets?

We love our furry friends, but a cursory examination of a dirty air filter when you have animals living in your home will reveal pet hair and dander. When you have pets living in your home, the life expectancy of the furnace filter is shortened. This problem is exacerbated with every additional animal, and it will be necessary to make adjustments based on the number of animals present. Again, we can only offer guidelines to follow, and the frequency may need to be altered to meet your needs.

If you have a single pet in your home, change a 1”-2” furnace filter every couple of months. This rises to every four months for a 4” filter and every six months if you’re using a 5” furnace filter.

For more than one animal, you’re going to need more frequent filter changes. Try a monthly filter change if you’re using 1”-2” filter, bi-montlhy for 4” filter, and every quarter for a 5” furnace filter.

To minimize furnace filter changes, reduce the strain on the HVAC system, and to improve the IAQ it’s a good idea to adopt a proactive approach. A pet that sheds a lot of hair should be groomed regularly (preferably outside the home) with appropriate brushes.

Smoking

The more people that smoke in the home, the shorter the furnace filter lifespan. If a single smoker is smoking indoors, you will need to change a 1”-2” filter every couple of months. A 4” filter should be changed every four months, and the 5” filter every six months or so. These numbers should be adjusted for additional smokers to every month for 1”-2” filters, bi-monthly for 4” filters, and quarterly for 5” filters.

If you’re concerned about your IAQ or you want to schedule some regular maintenance, contact your local heating and cooling specialist today.