Temperature stabilizer problem
My guess is that it is an Air Conditioner being used as a dehumidifier to prevent the buildup of moisture in your WC. That is why you are feeling a cold air stream on the other side. Modifying it would likely be cause for eviction as it could allow mold growth in the wet areas. I would look into fabricating some sort of deflector to keep the air stream from coming right down onto your desk. Cardboard and duct tape would suffice, just don't actually block the air flow, all you need do is direct it elsewhere.