air conditioning is great, but you can get a lot more from even the most limited system, with just a little attention:

all aircon units need cleaning frequently (-at least once every couple of months)

Try this: the softest brush you can find for your vacuum cleaner is the way to go (the crevice tool will damage the very delicate fins on the cooling heat transfer unit).
Finish off with a spray to freshen up: a very weak solution of Tea Tree Oil (to wipe out mold spores) and Eucalyptus Oil (to kill off any airborne bugs) will do the trick.

-The same solution will also cut through the dust on your ceiling fans