the Glacier Bay compressor will run two air conditioning evaporators when it is not being used for the frig or freezer (about 22 hours a day). In the main saloon, it does some good, but certainly isn't going to freeze meat. However in the small forward master cabin, it will drop the temperature by 1 deg/minute. That makes it quite practical to run, even overnight, from batteries at anchor. We did that a few times last summer in a heat wave on the St. Lawrence, when it was 40 deg. C and raining. i can dehumidify and chill the cabin by 20 degrees for the cost of about 8 AH.