The first thing my HVAC salesman told me was that if I was going to buy a new heating and air conditioning system, then I needed to make sure I had a lot of air filters, and I knew the proper way to change them. He said that no matter how good the HVAC system is, if the air filters aren’t replaced regularly, the HVAC will be almost useless. I took his advice, and I change my air filters on a regular schedule. I want my HVAC to run at its best so I can keep my energy bills at a minimum. I think the only really problem I have with the HVAC is that the air filters are really expensive. I started buying them at the home center, but I couldn’t afford them so often. Then I thought that maybe I get the air filters through Craigslist, but even though they said they were made for my model of HVAC, they didn’t fit. I had the same experience with Amazon, and ebay was a disaster. I knew that I had to have the air filters, so I called the HVAC company that I used to have my HVAC system installed. He told me that they also sold the air filters, and that I could buy them in bulk through them. I was surprised at how much cheaper the air filters were. I didn’t have to worry about them going bad, if I bought a bulk amount. As long as I had someplace dry to store them, it was the cheapest way to go. I wish I had been smart enough to think about buying the air filters from the HVAC company, about a year ago. I would have saved a lot of money.