I’m in a rental right now with a useless landlord, so I’m trying to fix the problem myself (or at least find the cause). My home’s central air AC unit is working, but doesn’t seem to be working well. There is cool air coming from the vents, but its less than I would expect, and when its 80f/27c outside, its rarely more than a single degree cooler. I’m looking for ideas to track down the problem. In particular, between the landlord’s neglect and the last tenant’s seemingly willful destruction I expect it’ll be something maintenance related.

So far I have checked:

• The unit size relative to the property (its about 2.5 tons for a 2,500 ft² property) which the internet seemed to say was fine. That said, its a bungalow with no attic and high-cielings, so Im not sure if that could have enough effect to account for this.

• Intakes and outlets inside the out aren’t blocked by furnature (although what I can see looking into them looks pretty dirty)

• I tried removing the furnace filter (which, from my understanding, is also used by the AC inside the house) temporarily, although didn’t notice a significant difference.

• I checked the cooling fins on the unit outside the house for obstructions, but there was little more than a bit of webs

I’m not an expert on these things at all, but is there anything else I can check or try?

Edit: unfortunately there is some condensation and frost on the coil box, so sounds like its a leak. Guess I’m looking at a fight with my landlord.