Hello, I hope the following assists you.
The air conditioning drain hose is in the middle of the engine bay quite low down, if you look near the heater coolant hoses and the gear change cables both close to the subframe you should see it, the hose is more visible from under the car. Also make sure that the heater housing itself isn't leaking the condensation in to the car as sometimes the condensation can get through the joint for the two halves of the heater housing. Check you can see condensation dripping from under the car in the middle of the rear section of the front subframe when the A.C is turned on, no condensation may well indicate a blocked drain hose.
Confirm that it is the A.C causing the water problem and not another fault such as water coming in when it rains.
Let me know if you have more questions regarding this and I'll reply as soon as I'm able to.