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Can an Air Filter Change Indicator Save You Money?

Can an Air Filter Change Indicator Save You Money?
3.5 (70.77%) 13 votes

G-99-air-filter-change-gageAn air filter change indicator can potentially save you hundreds of dollars on replacement air filters and can even lead to reduced operating costs for your air conditioner, heat pump or furnace.

How is this possible?

  • Change your furnace filter or air conditioner filter too often and it’s like throwing money away.
  • Wait too long between filter changes and equipment operating efficiency begins to decline and operating costs increase.

An air filter change indicator is designed to react to pressure drop across your air filter. As the filter becomes dirty the gauge reacts to the change in pressure drop and when the indicator needle points at the red “Change Filter” area of the gauge it is time to replace the filter. No more guessing.

How often should an air filter be changed?

Manufacturers often differ in their recommended filter change frequency. Some say every month, some say every other month and others recommend every three months and that’s only for 1 and 2 inch filters. If you use 4, 5 or 6 inch pleated air filters, recommendations vary from 3 months to a year.

Filters are expensive, especially the efficient varieties and the 4, 5 and 6 inch types so you don’t want to be changing them more often than absolutely necessary. It’s very difficult to know when a filter has reached the point where it is better to change it than to leave it in the system.

Manufacturers can’t really tell you because they can’t possibly know the conditions in every home, not to mention every geographic area. There are just too many variables to consider. If you follow a set schedule for your filter changes you are probably not getting the best value from your filters.

Leaving an air filter in your heating or air conditioning system too long costs money.

If you don’t replace you air filter often enough it begins to impact air flow and causes equipment operating efficiency to decline. A decrease in operating efficiency translates to higher operating costs. This means higher energy bills and nobody wants that either.

If left in a system long enough, a dirty filter will cause air flow restriction and can cause evaporator coils to ice up, heat exchangers to crack, longer run times and other equipment troubles that may require a service technician.

So what’s the solution?

Installing an air filter change indicator eliminates guessing from filter change schedules. You won’t be throwing money away by changing filters too often and you won’t be wasting money and dealing with the potential problems associated with leaving an air filter in too long.



p.s. You can’t rely on thermostat timers for this service either. Timers don’t react to the deteriorating conditions of your air filter. They only react based on hours of operation to remind you that you should change your filter. For a reliable indicator you should use an air filter change indicator.

About the author: Don has been working in the HVAC industry for more than 25 years and shares his experience and knowledge on this site. If you find the information presented here helpful please share with your friends.

{ 3 comments… add one }

  • Air Filters Delivered

    It is a difficult question to answer that is for sure. A filter change indicator is one solution, but most of the technology only allows them to be used on non-pleated media. There are programmable thermostats that remind you when to change but then again they are programmed to remind you every month, not on pressure drop or efficiency loss. The best way to do it is to check them at least once a month, if they are really dirty, change them. A good indication is holding them up to a light and seeing if you can see through them. Hope this helps!

  • DonaldT

    Thanks for the comment but I have to disagree:

    First I have to point out that I’m not talking about thermostat reminders, they are only ok, at best.

    Filter change indicators are best used on pleated air filters because pleated filters can have a huge impact on air flow when they become dirty. Although pleated air filters are the most common and among the most efficient, their design is really a weakness. All dirt collects on the surface of the filter and they begin to restrict air flow rapidly as they become dirty. This makes the air filter change indicators job even more important for these filters.

    Media filter pads distribute dust throughout the entire 1 or 2 inch thickness of the filter which reduces its impact on air flow and it can remain in the system longer before reduced air flow becomes a problem.

    Fiberglass disposable filters should never be used anyway because they are so inefficient, but they have similar characteristics as media filter pads.

    Holding a filter up to see how much light you can see is OK for someone like me, I change thousands of filters every year, but it is still a judgment call. How much light should you be able to see? Who wants to remove a filter and look at it to see if its too dirty to see through? An air filter change indicator eliminates the guesswork.

  • Anonymous

    That is nice to definitely find a site where the blogger knows what they are talking about.

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