I've got a chiller mainly as redundancy in case the house AC fails. When it is really hot and humid the UV sterilizer will push the temp in the tank close to 80, I let the chiller bring the temp back to 78. Chiller and some other equipment is in a closet near the tank, there is an exhaust fan in the closet that vents to the outside
I used to cool the tank with fans blowing on the surface, keeping the temperature at 27C using a thermostat. My 250 liter tank was evaporating about 10 liters of water every day... I bought a Teco-500 chiller recently, and set it to 25C - my evaporation dropped to about 2 liters a day, and the corals are getting better coloration. However, all the hot air is in the room now, making it much hotter for my own presence, especially at night - I hate to turn on the AC but now I am forced, to be able to sleep. Love the topic starter's photo, perhaps I need to do the same - just, need to arrange plumbing from the tank to window, and drill a large hole in the wall. I am a bit concerned, though, if cold air would be coming to my room through the chiller during winter...
Just added a chiller, once I put all my lights in the canopy the tank got hotter. I use fans as well but this gives me a good backup for an ac going down or power outages where my generator is running the house and the portable ac. The chiller worked extremely well yesterday.