Air conditioners are energy hogs and so are chillers. Chillers blow VERY warm air back into the room making the room even hotter, so chillers are best placed in a protected area outside or in another room. An air conditioned room is usually cool enough that the tank can be kept cool enough with a few fans running near the lights and sump. With these considerations, I would just purchase an in-window or standalone air conditioner for the room the aquarium is in so that you can enjoy the cool temperature as much as your tank does!
Another way to work around having to use a chiller is to take considerations when purchasing equipment - especially pumps. Both return pumps and powerheads can add a lot of heat to the water, so choosing carefully can help. Lighting is another consideration with halides being the hottest, then T5s, and LEDs being the coolest. That said, my 90-gallon SPS reef has a "hot" return pump and 2x250 watt halides and I am able to keep it cool enough with a fan blowing across the water surface to blow the hot air from the lights away and one blowing into the sump. I do have central air conditioning, though we keep the house a bit warmer than many people do at 23C. If the house is warmer than 23C the tank will get too warm.