An 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.

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 the 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.

More about air filter change indicators.

Question: I have recently moved into a house and the furnace uses an electrostatic air filter filter and I am unfamiliar with it.  We have 2 filters one is in the furnace and 1 is leaning up against the wall…the slot is big enough for both filters, do I put them both in or would that restrict the airflow…is the sole purpose of having 2 to alternate when cleaning the other.  Thank you in advance for helping me with this question….thank you also for the info on cleaning it this website is very helpful.

It is fairly common for people to have two electrostatic filters. While one is drying after being cleaned the other is used and they are alternated this way. You are also correct about using both of these filters in a heating or air conditioning system. Installing both filters at the same time would definitely cause problems with air flow.

Restricting air flow can cause many different problems:

Restricting air flow in an air conditioner

• Evaporator coils icing up
• Poor air circulation in the conditioned space
• Increased operating costs due to longer run times
• A decrease in equipment efficiency

Restricting air flow in a furnace

• Furnaces cycling on high limit switches
• Cracked heat exchangers
• Increased fuel consumption due to longer run times
• A decrease in efficiency

The above are only some of the potential problems that can result from restricting air flow.