Last year we added a room onto our house, this photo is the hvac ductwork in the attic. As part of this project, we added central air conditioning. Previously we had an evaporative cooler and a small window a/c unit. We got by, there were a few weeks when it was humid and uncomfortable. Now we have a central evap cooler and central a/c.
Our timing was right on. This year the Az monsoon season brought lots of rain. This is great, but it also was very humid – not great, in fact one reason I moved to Az was to get away from humid weather. The new a/c really does a good job in removing excess moisture from the interior air. We were concerned about running up Phoenix style summer electric bills. When I lived there a decade and a half ago, $300+ electric bills were common 4 – 5 months out of the year. Phoenix summers are much fiercer than what we get in Prescott, by far. The two months that we have ran the a/c have given us electric bills in the $160 range. I was expecting much worse. And when it’s hot and dry here the evaporative cooler works just fine. The new one we have uses a thermostat just like a/c and the furnace do.