I rent out apartments in my hometown. The apartment is right near a college so that I frequently get college aged teenagers renting from me. Most of that time period the kids are decent renters. Occasionally they could be a problem with the noise level. The most recent crop of kids I have are terrible. The problem is not the noise level. They are totally helpless in the case of repairs. I am constantly to the site the different rooms performing maintenance on plumbing, water, electric in addition to HVAC. The HVAC is this worst. I have no skills within the heating and cooling department. So, almost daily I have to call a HVAC contractor to make a repair. I have learned a little en route however. I now know generally if the HVAC system is not doing work too great, it probably contains a dirty filter. A new filter is a couple of bucks. Having a HVAC professional over is way more. I also know how to decontaminate out an air conditioner. I can wipe out mold on a cooling coil and algae from the condensate drain. That will stop the AC from leaking. A heater system that turns on and off might just be dirty. Or I should just lubricate and oil the unit device. Those are my standard tricks i now know to do. Precisely what I do to prevent your HVAC call. But with this approach crop of kids. I have to constantly come over the building and look at HVAC devices. It gets really annoying eventually.