Originally Posted by chase33
The air may be a blessing in the summer as it will help keep temps down possibly removing the need for a skimmer.
Just to avoid any confusion, me thinks he meant "chiller", not "skimmer."
Most likely, your heater is going to be set in the range of 77-80 or so, I'm guessing. So I don't think the heated air is going to be an issue. Unless your air comes screaming out at 100 degrees or something!
I still am struggling to see how your 200W heater couldn't keep up with the air conditioned air, even blowing directly on it. But hey... I'm amazed at how quickly a little fan blowing across the top of a tank can drop the temp by 2 degrees, even with no a/c.
What I'd do next summer, rather than block off the a/c, is actually get a bigger heater that could keep up with the drop in temp. It's way easier to heat water up than it is to cool it down, and having a "built in" chiller would be a pretty cool thing.