Living in a world without HVAC units is as sad as residing anywhere without water.
I was sent to a different dimension through a portal into a world where nowone knows what an a/c or furnace is.
The people in this world solely live on natural heating and cooling. Instead of figuring out how to build a central air conditioner unit, they just build their houses in the caves where it is consistently cool. The biggest problem with this is that the cool caves can’t be turned up or down like an cooling system device can. Some afternoons it is too cold, and other afternoons it is not quite cool enough. In the winter season time, instead of developing a portable space heating system or a gas furnace, these people rely solely on fire to keep them warm. There are no zone controlled boilers like there are in our world that are able to make one room sizzling and another hot. In this world you are either too sizzling or too cool. I tried to introduce a simple portable space heater, but the people just couldn’t seem to understand. I then had a goal. I was going to make a window a/c for every home in my neighborhood and see if the people would accept it. I am a honestly experienced cooling expert, so I knew how to build a window a/c that was honestly fantastic quality! Even though I am an HVAC serviceman, it still took me various months to finish all of the window a/cs for all of my neighbors.