By portable air con do you mean the old style 'bonair' units that you constantly have to put water into? or the air con units that sit in the windows?

The bon air units only give out one blast of air in the direction its basically pointing in. My parents have two of the other air con units as they are renting.. however they don't move them around as they have them mounted in their windows and got a special size glass mounted around it so they are permanant. Do research on them because you can get all different sizes and if you have a medium to large room there is no point in buying a small one as it will do nothing. just waste power and money. they have a small one in their bedroom because it is a really small house and the largest possible in their living areas. for that one they had to get a special power point in as it uses more power than the regular points give out... shop around and so some research on them (i know you don't have long - but its worth the money and the effort)