When to change the furnace filter? It is a very common question from first time home buyers. It needs a very simple visual check for the first time and a regular frequency of filter change then after. When you are totally new to the furnace, it may seem like a rocket science, but it is not!

It is not very difficult to inspect a dirty filter. The dirt and dust on the filter are very easy to locate and inspect. It is a good idea to keep a log to record when did you last changed it. If it is a new house or new purchase, either ask the builder or previous owner when it was changed the last. If you don’t find the information, just simply change it as it doesn’t cost you much. You are only spending 8 to 10 cents per day to keep your house breath healthy!!

The higher the thickness, the lesser is the frequency of changing the filter. As a rule of thumb, multiply the thickness with 2 and you will arrive at a number of months for replacement. For example, 2-inch filter may need replacement in 4 months.

For 1 to 2-inch filter, replace every 2 to 4 months

For 3 to 4-inch filter, replace every 6 to 8 months

For 5 to 6-inch filter, replace every 10 to 12 months

For residential use, the most common ones are 1- or 2-inch filters. And the best solution is to change them at start of every season.

Read More on Furnace Filters:

What happens if you forget to change your furnace filter?

What happens if you forget to change your furnace filter? For a short period, let’s say couple of months, it won’t damage anything much. But for a longer period, keeping the furnace without replacing filters can cause multiple issues. Read More on “What happens if you forget to change your furnace filter?”