I read that there were homes in Ancient Rome that used water going through channels in the walls to create an indoor cooling effect, which is mind blowing to consider in its scope at the time.
Granted, you had to be wealthy and perhaps well-connected to live in a home like this, but it’s still an example of early indoor air cooling almost two thousand years before the invention of the modern air conditioner.
Before that, water was evaporated in open windows from hanging reeds in Ancient Egypt to create one of the world’s first evaporative cooling effects. This is how a swamp cooler works in basic principles. You push air through a wet medium, forcing the moisture to evaporate into the air coming out the other end. If done in the right conditions, the temperature of the air will drop as it goes through the cycle. It’s energy efficient, but you can’t really rely on evaporative cooling in wetter environments where humidity levels are over 60% in the outdoor environment. As far as heating is concerned, I have switched to hydronic radiant heated flooring because of the energy efficiency. The water is heated in a steam boiler using natural gas, and then the hot water is sent to pipes inside my floors to heat my house from the ground up. It’s a much more efficient use of heating energy than a fan-forced furnace that utilizes ductwork instead. Fan-forced furnaces are difficult because the act of blowing air from a fan over a heating element has a cooling effect right out the gate. So you’re cooling off a heating element just to get hot air in your home. Compared to radiant heat, fan-forced heating is extremely inefficient.