The Heating, Ventilation, plus A/C system in my old cabin did not have an air filter in place when I moved in. Subsequently, it became a challenge to guess just what size A/C filter I should use. It would have been nice to have the Heating, Ventilation, plus A/C guide to peruse prior to my air filter shopping, but there wasn’t 1. So I was on my own to figure out just what air filter I should have. I grabbed my trusty tape measure to find out the exact length, width plus depth of the A/C filter area, plus I copied down what Heating, Ventilation, plus A/C names I could find on the a/c. Then armed with this Heating, Ventilation, plus A/C information, I consulted the internet plus found the data I would need to acquire the exact air filter for my heating plus cooling system. However, now that I see that there are so many different types of air filters to choose from, I am once again, confused as to what type of air filter that my A/C system needs. Since I now guess the size of the air filter, I must educate myself on the different types of air filters. Online I found pleated air filters, plus fiberglass air filters. As well as ratings on the air filters as to the effectiveness of the filters’ trapping ability. The higher the number of the rating on the A/C filter, the smaller the particles to be trapped, and that sounds like a better air filter to me, so I headed out to the hardware store to buy my air filters for my new, old home.