Report "Condensation freezing. I live in Kenai, Alaska and installed a 300622 in my garage a couple years ago. In the winter when it gets coldest the more the heater runs the more ice I get going up the wall from the exhaust. I keep the temp at about 55 to 58 degrees. Do I need to extend the exhaust above the roof and does this effect the air intake? What kind of stack do I need to use for it and how will it effect the heater itself? I have pics to send it needed. Thanks j. gregson [email protected]"