Different air filters for different problems

More often than not I am doing the silliest things because I am a careless person, but I am here to tell you about our mistakes in the hopes that you don’t make the same 1s! My most recent mistake cost me a little bit of cash in my pocket so I was pretty bummed. I had noticed that our flu symptoms were getting pretty bad, plus after talking to a friend that is an HVAC specialist I decided to to order some up-to-date air filters for our gas furnace along with the entire HVAC system. She told me just how crucial air filters can be plus I figured I should try them out before I had someone come out to my place and take a look at our HVAC system. I went online plus searched for gas furnace filters. I had later picked up a pretty cheap pack in bulk plus figured that I would need them for a few years. I ordered almost 200 air filters for our gas furnace plus when they arrived I couldn’t know that they didn’t fit. I don’t know the actual reason, but I completely forgot to measure the filters for our gas furnace. I figured out that none of the filters I got fit our HVAC system so now I have an entire box of air filters that are no use to me. I gave our HVAC friend the box of air filters plus in exchange she gave me a few that fit the way it should. She told me that there are several different sizes when it comes to the HVAC world, plus now I know that I just need to be more careful when dealing with my heating and cooling system.