If the wetness is due to "condensation", you need air flow to remove the moist vapors before they condensate on the pad. So, air circulation is the answer.
However, you will still want to get to the root cause which could be just a natural occurrence due to your dog's body, or it could be due to being too hot, or from being overweight, or to a lesser degree, a medical issue.
But for now, to solve the issue, air circulation will dissipate the vapors into the surrounding space and not let it linger and condensate on the dog's sleeping pad.