right now I am dry hopping a 3 gallon batch in a better bottle. my freezer is 7.0 cubic feet. I am using a blow off tube. I have taped the probe, under paper towels, to the outside of the blow off tube sanitizer jar. it is plastic. I have been running this set up as is for two weeks and have been keeping very constant temperatures. I also have the freezer set in its warmest setting. right now it turns on maybe once every 1.5 hours or so. when it's cooler in la, it runs less, particularly at night.