I had recently moved into a brand new apartment. It was really weird at first when I needed to use the air conditioning. The air conditioning worked completely fine. It blew out the cool air that I needed to remain comfortable. I definitely never had any issue with that. However, whenever it would turn on it made a very loud noise. I had met up with my neighbor who lived downstairs and she had said that even she could hear it. I definitely had to call the maintenance guy about this noise coming from the HVAC system every time I wanted the air conditioning to run. The maintenance guy came over the same day and looked at the system. He had found that there was something missing from the fan blade. It was causing the fan blade to hit up against the system. So every time the system turned on, the fan blade would hit something. That is where the exact noise was coming from. He said he was going to have to order the part he needed in order to fix the noise. So I was going to have to deal with that noise just a little bit longer. He finally got the part in and came right over to fix the issue. Luckily I was not home at the time. I had some errands to run that day. In fact I came home and didn’t even realize he had come for awhile because the air conditioning never made a noise again and it was so hard for me to be able to notice if it was fixed. The air conditioning system was so quiet now that I had forgotten all about it.