When I go to buy air filters for my central HVAC system idea unit I like to buy them in bulk! And if I do not buy in bulk I like to buy at least 2 large packs, the reason for this is to save myself headache, gas and time from having to keep coming back to the hardware store every single month, then I change the air filter of my central HVAC system idea once a month even if it does not look or feel like it needs to be changed.
This is a way to ensure that my central HVAC system idea is always working at the full power it was designed to.
It also helps with keeping the air vents and the ductwork clean as well. I only get our ductwork to our central HVAC system cleaned once a year, and sometimes I may even skip it if it seems that there is no problem and the local heating and cooling specialist reports no troubles when they do their official heat and air conditioning system tune up and check up every season. I think I am pretty much set in terms of air filters for my central HVAC system. I bought enough this last time to last me about a year or maybe even more! I also should mention that I buy washable air filters too, which extends the use of them, and washable air filters are pretty cool I have to tell you!