you can put a piece of cardboard up to block some of the air flow to allow it to keep a warmer temp so that you have heat. i would not take the fan off because what if you start to over heat and dont have a fan to cool it down with? leave the fan on and put a piece of board across part of the radiator. if its that important buy or make a cover to put on your grill for the winter time and remove it in the summer like the OTR drivers.