How do I deal with leaks in my air conditioning? How do you typically detect and fix air leaks? Where are the places that they are common? All this in the spirit of running an efficient cooling system.
If you mean cold air leaks in a raised floor plenum, typical problem spots are the joints between the wall and the adjoining row of tiles, and floor cutouts for cabling, piping, pillars, etc. Foam gaskets (like weatherstripping) can be effective against wall-to-tile leaks and there are a variety of grommets, brushes, pillows and other devices for minimizing air loss from cutouts. For any solution, make sure the product has a fire rating appropriate for your local codes.
An infrared thermometer can be useful for troubleshooting, if you can't feel the actual air leak with your hand. Just remember that it measures the temperature of solid objects, not air temperature, so an edge that is much colder than the rest of the tile will indicate a possible leak.
If that's not what you meant, you'll have to clarify your question.
can you give us a little more detail as to what cooling system you are currently implementing in your data center?
do you have raised floors? have you adopted room level cooling or spot specific cooling? modular cooling? or have you adopted airflow management techniques?