How Often You Should Change a 4-Inch Filter

You’ve heard us talk about air filters before. In our last blog, we talked about the importance of changing 1-inch filters every 30 days.

But some houses have 4-inch filters. In fact, every attic unit we install has a 4-inch filter box. We do have upgraded filtration options, but our standard installation is a 4-inch filter box.

We suggest that you change a 4-inch filter every six months. There are many cases where we find that customers can go a whole year before needing to change their air filter! (This depends on living habits, and whether or not customers have pets.)

More Cost Effective Than 1-Inch Filters

Replacing a 4 inch filter in an HVAC unit

4-inch filters are fairly common, and you can probably buy them at Walmart. You’ll spend a little more money up front, but if you change your 1-inch filters correctly then over the course of a year you will save money with the 4-inch filters. Not only will they filter better but they’re cheaper in the long run. You should be able to buy a two-pack of these filters for about $40.

The 1-inch filters are sometimes $15 each, and you are supposed to change them every 30 days! You especially have to make sure you change them often in the summer time, as your fan gets more use then and pulls in a lot more air, which makes the filter get dirty faster. This is why in the summer time (which lasts a long time in Texas) we suggest every 30 days.

Why We Prefer 4-Inch Filters

We prefer the 4-inch filters. They keep the system very clean. We recently serviced a unit that we installed in 2008, and it still looks incredibly clean! It’s over 10 years old and it still looks brand new on the inside! That’s exactly what we want to see! The more we can keep the system clean, the more efficient it will stay for longer.

The most efficient day of your system is Day 1, because everything is clean! This is why the best thing you can do for your system is to keep the filter changed.