This is a hard question to answer because there are many makes and models on the market and they vary a great deal in quality. Some other key factors to furnace filter longevity are the indoor air quality (IAQ), the level of contaminants, and whether you have pets. These factors make the filter work harder, and this will have a detrimental effect on the furnace filter’s lifespan. In this article, we will take a closer look at furnace filters and how they can have a dramatic effect on your health and heating system.

What is a Furnace Filter?

The primary purpose of the furnace filter is to protect the heating and cooling equipment against damage from contaminants. The air in the home or business is pulled into the equipment and circulated through filters multiple times each day. The blower unit drives a fan that pushes the treated air (warm or cool) out into the ductwork and throughout the home. During this journey, the air can pick up a wide variety of contaminants, including dirt, dust, pollen, pet dander, smoke, smog, dust mite debris, mold spores, and more. This material is bad for our health, and it can cause damage to the sensitive heating and cooling equipment. The furnace filter is usually located in the blower unit compartment, and full replacement details are in the owner’s manual for your system. If you’re not sure how to proceed, contact your local heating and cooling specialist for help.

What Furnace Types are Available

When you’ve located the furnace filter it’s time to look at the unit to see which type you have in the system. Let’s take a look at the various types of furnace filters in common use today:

  • Fiberglass: These are made from fiberglass or other synthetic materials, and they are the most basic type of filter used today. They are a popular choice because they are inexpensive, but they don’t offer much protection against smaller particulates. That said, they will prevent large dust particles from entering the system.
  • Pleated: These are folded filters that cover more surface area to capture a wider variety of contaminants in the pleats. These are certainly an upgrade from fiberglass filters, and they are reasonably priced for their acceptable performance.
  • Electrostatic: These are semi-permanent and washable filters that hold a low-level electrical charge which attracts particulates to stick to the surface. These cost more than pleated filters, but because they are washable, they last a long-time.
  • HEPA: High-efficiency particulate air (HEPA) filters are extremely effective for the removal of pollutants with an efficiency of 99% on particles that are 0.3 microns or larger.

When Do I Need to Replace a Furnace Filter?

Every furnace filter type has specific recommendations for the filter change frequency. Some can be washed and reused, and others must be replaced entirely. As a rule of thumb, a filter should be replaced every 3-6 months. A thicker filter tends to last longer and they may need changing every 9-12 months.

Here is a general filter size reference that may help:

  • 1” Filter: 1-3 Months
  • 2” Filter: 1-3 Months
  • 3” Filter: 6-9 Months
  • 4” Filter: 6-9 Months
  • 5” Filter: 9-12 Months
  • 6” Filter: 9-12 Months

Why Are Furnace Filter Replacements Important?

There are four main reasons why a regular furnace filter replacement is essential:

1.   Improving Energy Efficiency

The heating and cooling system relies on a steady supply of air to run smoothly and efficiently. If the filter is clogged with dirt and debris it will limit the volume of air that can pass through the filter. This forces the system to work hard to compensate, and overworked equipment is prone to failure. Hard working components also consume more energy and this will drive up the electricity bills too. When you consider that an air filter change is so simple, it makes good sense to change it on time.

2.   Protecting Our Health

Over time an air filter will get dirtier as the dust, dirt, dander, and other contaminants accumulate on the surface. These pollutants will seep into the air that we breathe indoors, which degrades the indoor air quality (IAQ). People that suffer from allergies and pre-existing respiratory diseases may be the first people to notice the change. Changing the air filter will trap more of these airborne contaminants, which improves our health.

3.   Protecting the Equipment

As we mentioned earlier, overworked equipment will cause components to fail and drive up the energy bills. But, over time, this damage will have a detrimental effect on the useful lifespan of the entire system. Key components such as the blower unit may burn out and it may not be economically viable to repair the system. This can lead to an expensive and unexpected replacement that could have been avoided with simple regular furnace filter changes.

4.   Decreasing Maintenance Costs

A blocked air filter can increase the maintenance costs significantly. If the blower unit isn’t working properly or the ductwork is dirty, there will be a greater need for repairs and cleaning. More dust will be circulating throughout the home, and this will increase the time required for vacuuming, dusting, and other cleaning tasks. If you want to save time and money, it’s a great idea to make regular furnace filter changes a priority.

In Conclusion

If you cannot remember when the filter was replaced, it’s a good time to do it now. Make a note of the filter change date and set a reminder for the next filter change now. This proactive approach will help you to avoid or mitigate the effects of the problems mentioned in this article. The full details for a filter change are in the owner’s manual for your heating and cooling system. If you’ve misplaced the manual search for a free pdf copy online and print out a copy if you want redundancy for power outages.

If you need to schedule some essential maintenance for your HVAC system, contact your local heating and cooling specialist.