Air Conditioning - Hot room, any ideas?

I am not sure if this is the right place for this but here goes. I am having a tough time keeping a room of mine cool. It used to be the back patio but was walled and turned into a living room/game room. It measures maybe 10 x 25 and is all dry wall. Has a 80in by 50in sliding acyclic panel :thumbdn: window facing the south (in Phoenix which kind of gets hit by the sun but not really) a standard exterior door and a opening to the kitchen of maybe 68w x 80h.

There was never a duct vent ran into this room. I can get the rest of the house cool but this room just doesn't want to cool down even when I have fans pushing air in.

I have looked at a few options but one thing can be done at a time sorta.

I am thinking of running some duct-work into the room and having all the vents balanced.

Getting a window ac unit or a portable ac unit.

Maybe its the window? It feels very warm to the touch even when the sun isn't on it. Replace it?

The door has a little bit of light coming though. Would this cause a majority of the problem?

Also my house is 2200+ sq ft with the one return line more to-wards the back of the house. Would it be helpful to add a 2nd return to help better cool the house? Maybe add that 2nd return and a supply in the back room?

What are your thoughts? What is the main cause for my hot room? Thanks :thumbup:

Id say it could be any of your things you have found. The room is very big so your unit might be under sized now! Will need more than one duct. Do a heat load to see how much cooling you will need.

Air conditioning in a split system does most of its work using the return air ducts, of which you have none. This is why trying to blow the cooled air into your room has little effect.

The cheapest route would be to get a window unit.