Hey recently built a living space in a shop there 2 rooms roughly 15'×18' one on the main floor and one directly above it. Looking for the best way to air condition both rooms already finished so cant run ducting but was wondering be best to put a unit upstairs and cut a vent in between joist let the cold air drop ? Theres multiple windows and rooms are cornered on outside walls steel heats them up pretty good. Any advice would be great thanks*

I am on the ground floor of a 3-story apartment building. The apartments in my stack are 2 bdrm. with a third room that is a living, dining, kitchen combo. There is a small window a/c unit in the wall of the main room that is supposed to cool all 3 rooms. The tenants in the unit above me. Their Master BR is directly above mine. They bought a free-standing a/c unit which causes noisy vibrations in my Master BR but not in my other rooms. I complained to management and they finally build some sort of a noise suppression platform which I have not been allowed to view. Now, when I walk in the Master, I don't hear the vibration noise. However, when I lay down in my bed, I still hear the vibrations. I made sure my bed frame is not touching the wall. Sometimes, it helps if I sleep with my head at the foot of the bed but not always. Does anyone out there understand why I now only hear the noise when I laying down. I can clearly hear the noise begin and end as the thermostat cycles the unit on and off. I tap my ceiling with a broomstick when the noise gets really bad. At first, this cause them to turn the unit off. Now, they just ignore it until I get tired of tapping! Thanks for your ideas and suggestions.