I have been actively involved in the air conditioning and heating business for over 30 years and one particular non-scientific example of the importance of clean filters stands out.

A good friend of mine told me the story about a “double” that he rented. The tenants on both sides had the same square footage and lived similar life styles. The tenants were talking one month and found that the gas bill for the one side was almost 50% more than the other. Shortly after that he received the next month’s bill and it was more than 50% higher so he called the landlord and told him something had to wrong with the furnace. The landlord asked the tenant if the furnace was still heating the apartment OK and if the filter was clean. The tenant said the furnace seemed to be working OK and assured him the filter was clean.

The next bill came at the end of January and the one tenant paid about $80 while the other one had a bill of over $150. The now irate tenant called the landlord again. The landlord asked the same question, has the furnace been heating OK and are the filters clean? He answered yes to both questions so the landlord we out to check things out for himself.

When the landlord arrived the next morning he found that the furnace was working OK but that the filter was so plugged it looked like a piece of cardboard. He changed the filter and the next month. The gas bills were within a dollar of each other!

Keep your filters clean!

Mark Swepston, President