Your first step is to get one with two hoses rather than one. The ones with one hose suck air out of your house almost as fast as it can be cooled.

Bought the one below for a server closet at work, has run 24/7 for over a year now without problems. And we've never had to empty the tank, since the 2nd hose exhausts most of the moisture. Agree with ionized above, the single hose models are mostly useless.

Here is a link that might be useful: Two hose portable AC

I own a single hose and it is great to sit or stand in front of but to cool a room you might as well forget it.

@crdnh do u think the 2 hose btu is close to the same btu as wall/window unit?

No, the portable doesn't "feel" nearly as powerful as a window unit, even though it might be rated the same btus. I suspect that's because the portable unit itself gives off heat into the room, which is less of a factor in a window AC.

Portables are more expensive up front and less efficient - the EER of a 12Kbtu/hr portable is 8.7, vs. 10.8+ for a window unit. Not sure I'd recommend a portable if a window unit is an option.

a window is available but i only have one in the bedroom and want to have access to it, also I might move this in between the office and the bedroom.

i am not even sure i need this unit as the 15kbtu window unit in the living room is doing a decent job, i was looking at this as more a secondary back up kinda unit....thanx for answering

You should as yourself how big is your area need to cool down, I can say that the cooling performance can be same as window one.

Here is a link that might be useful: Visit here