Air Filter Replacement Cost – How Much Should You Spend?

Air filter replacement is an important component of heating and cooling system maintenance. While some HVAC systems have reusable filters that can be washed, dried, and reinserted, many systems use disposable filters that should be replaced at regular intervals.

There are many different air filter replacements available for purchase, through HVAC contractors or your local hardware store. How much does an air filter cost? How do I find the right air filter replacement size? What does an air filter even do, anyway? answers your questions about air filter replacement, air filter cost, and more.

What Does an Air Filter Do?

An HVAC system’s air filter (also referred to as a furnace filter) serves a primary role as protector of the system’s blower motor. The air filter works to keep the blower motor clean by removing airborne contaminants passing through the system.

Without the air filter, all the dust, dirt, danger, and other particles would pass into the blower motor chamber from the return ducting, settling on the blower motor. These contaminants accumulate, which has the potential to cause damage to the blower and other components within your HVAC system.

While creating a cleaner blower motor and compartment, air filters also create cleaner indoor air through contaminant removal. While not their main job, this is a valuable advantage they offer. Filters receive a MERV (minimum efficiency reporting value) rating that reflects contaminant removal efficiency. MERV values start at 1 on the low end and go up to 16, but MERV 12 or 13 is the highest that should be used in a residential HVAC system, depending on the model.

How Much Does an Air Filter Cost?

Furnace air filter cost varies greatly from one product to the next. This is based on MERV rating, filter material, thickness, retailer, and other factors. A standard disposable 1” air filter replacement costs as little as a few dollars at your local home improvement store, and it lasts about a month. A 6” pleated filter that is meant to be changed every 9 to 12 months has a higher cost, but delivers better value.

What’s the Right Size for My Air Filter Replacement?

There are many air filter replacement sizes available – the size you need depends on your HVAC system. Your equipment owner’s manual should provide filter sizing info, but often the quickest and easiest way to determine the right size air filter replacement is to look at the existing filter.

Remove the existing filter from the filter compartment. The filter’s frame will have information including the brand, filter dimensions, MERV rating, and possibly even the part number. With this information, you know what to look for when you shop for an air filter replacement.

How Often Is Air Filter Replacement Necessary?

With air constantly flowing through your home’s heating and cooling system, over time the filter becomes clogged and must be changed. How often you need air filter replacement depends on many factors, such as how many people and pets live in your home, the type of filter, how often your HVAC system runs, and other air quality issues present in your home.

Air filter manufacturers provide recommendations as to the frequency an air filter should be replaced. These are good guidelines to work off, but you should perform monthly checks of your system’s filter to visually look for a clogged surface.

Air filter replacement guidelines are:

  • 1″ Furnace Filter: 1 – 3 Months
  • 2″ Furnace Filter: 1 – 3 Months
  • 3″ Furnace Filter: 6 – 9 Months
  • 4″ Furnace Filter: 6 – 9 Months
  • 5″ Furnace Filter: 9 – 12 Months
  • 6″ Furnace Filter: 9 – 12 Months

What Happens If I Skip Air Filter Replacement?

Skipping air filter replacement and continuing to operate your heating and cooling systems with a dirty filter has the potential to cause serious problems with system performance. When you skip filter changes, the following are possibilities:

  • System overheating: When the air filter is clogged with debris because it has not been changed, air cannot move through the system as it should. Your HVAC system must overwork in attempts to draw air through the clogged filter. This extra work can easily cause the system to overheat, which damages components and could also pose a fire risk. When the system overheats, it shuts down to safeguard against fires – leaving you without heating or cooling until the system can safely begin a new cycle.
  • Energy waste: With your heating and cooling systems working harder to force air through the dirty filter, more energy is consumed – this energy wouldn’t be necessary if air filter replacement was done properly. Not changing your air filter results in additional energy expenses and higher utility bills.
  • Poor air quality: While not the primary purpose of an air filter, air filter replacement does work to remove contaminants from the indoor air supply, improving air quality. A clogged filter cannot extract more pollutants, so they continue to circulate around the home. Dirty air filters lead to more allergens and contaminant particles in the home, increased allergy symptoms, and dirtier surfaces throughout.