Unfortunately there was a bad start to this reservation. The previous guest turned out to be very filthy and it took a much longer time than usual to cleanup after they left which delayed this guest's access to the room by about an hour. The guest had already wanted to check in at daybreak as they messaged me very early that morning; which I was not able to accommodate as the previous guests didn't leave until after 1. Unfortunately this all combined to give a bad first impression which affected these guests' entire view of their stay. After they complained to airbnb during their check in, I'd offered a full refund as I was sure they would never be happy with their stay, but they declined the offer. I also tried to accommodate their every request and provided the additional fan they requested (there were two a/c available to cool the space including the hallway one), but it was all to no real avail. You can read my own experience on this reservation in my own review of this guest.
To be fair to their posted comment, they happened to check in on a very hot and muggy day and it was warmer than usual (not quite cool as usual) in the space that day when I was cleaning up. However by the time I dropped off the fan later on the evening of their check in, the space had already cooled back down to normal and I didn't notice any unusual warmth in the space for the remaining part of the reservation. After this guest left I did find that the a/c's filter had gotten clogged with dirt and has since been cleaned; this might have affected the a/c's overall power during their stay. Either way, there doesn't appear to be any issue cooling the space since then and I will be replacing this unit with a newer, more powerful unit which has come into stock.