I usually buy a new air filter for my heating and AC system once a month.
I make frequent trips to the hardware store, because of my business.
I work as an electrical engineer and I have my own company. I work on lots of different construction projects. I always provide consults on building management systems and smart homes. Since I am frequently at the hardware store, there is really no reason to have a lot of air filters at the house. If there is a sale, that is an entirely different thing. I got the air filters on sale at the hardware store last week. They are normally $11 each but they were on sale for $8 each. 30% savings was hard to let go. I decided to buy a whole box of 12. Now my wife and I won’t need air filters for the heating and AC system for the next year. At that price, we can even afford to change them every two weeks. It’s not as if it would hurt the indoor air quality. It is frequently dusty and we have to worry about viruses like covid and monkeypox. I definitely want my family to be healthy. It also helps the health of the heating and air conditioning system. When the air filters are changed more frequently, the heating and air conditioning system is cleaner and runs more efficiently. During the times when the temperatures outside are over 100°, it’s nice to know that my heating and air conditioning system is running at peak performance with clean parts