No, there is no risk of condensation.
Here's an illustration: picture yourself taking a hot beverage outside on a cold winter day. No condensation, right? Now, picture yourself taking a cold beverage outside on a hot and humid day. Tons of condensation, right?
Your computer is like the hot beverage and the cold air from the air conditioner is like the cold winter day.
You could even just compare a hot and cold beverage on the same hot and humid day and again, there won't be any condensation on the hot beverage because the surface of the cup is warmer than the temperature of the air. Therefore, none of the moisture in the air can condense onto it.
In other words, this is 100% safe. If you want to be sure, then test this using any object in your house. Stick it in the path of the cold air and leave it there. You'll never see condensation on it. The only way you could get moisture to condense onto a warm object - or even one at room temperature, is by blowing warm or hot steamy air at it. You're blowing cold air onto warm or semi-warm objects, so condensation is impossible. Well, you could make something in your case become just as cold as the air coming out of the air conditioner, and then you could take it outside as fast as you can run and then you might see a LITTLE bit of condensation, but only if that thing is still cold enough by the time you get outside.
Not to be too redundant, but in order for condensation to be possible on your rig, your rig would have to be significantly colder than the air coming from the air conditioner, and the air coming from the air conditioner would have to contain enough moisture to condense onto your rig. However, that would result in frost because that's about how cold your rig would have to be! So, hopefully you can see how safe this is now.
If you still need assurance, then start learning about what the Dew Point is. The Dew Point is determined by the temperature and how much moisture is in the air. The more moisture, the higher the Dew Point. The reason it's called the "Dew Point" is, that's the temperature point where dew begins to form, meaning where moisture condenses so much that you now have dew drops on everything. This is why clouds form: moisture from the warmer air mass is condensing onto relatively cold air mass because there's enough moisture contained in the warm air mass. You'll never see moisture condensing onto warm air. It just can't happen because it evaporates. That's why fog goes away when the sun comes out.
Edited by TwoCables - 7/6/13 at 9:18pm