What exactly does an a/c filter do?

We rent our apartment, and the landlord provides us with air filters for our Heating as well as Air Conditioning idea however the filters do not do much for us. The filter media is so thin I can see through it as well as it is not woven at all, and i think he gets them at a second hand store or something. I really don’t guess that it does anything at all. The only thing it can catch would be leaves as well as similar sized things. I don’t have leaves floating around in my house. I want a filter to catch dust as that is floating around in my house. I’ve complained to him a few times about the filters that are gave. After a while, the director said that I was free to purchase my own if I didn’t like using these ones. I didn’t think that complaining any more would do any good so I went out as well as bought my own filter, then when I opened up the tiny door to update the filter I saw that the old, flimsy one had entirely fallen down inside of the HVAC duct. I had to work very hard a bit to get it out. I think that explains the rattle noise the people I was with and I have been hearing. I fished it up as well as installed my brand new one. The new one felt solid as well as wasn’t seethru, then after it was installed, my Heating as well as Air Conditioning unit was much more quiet than the last one. Only time will tell if it helps with the dust even though I guess that it will. The aged filter was hardly better than nothing at all. I am a bit upset that I will have to pay for my own filter every month even though I think it will be worth it.

air filter