Rotating Main -20 C Freezer Defrost Schedule (estimated every 7 months or as needed)
Rotating Working -20 C Enzyme Freezer Defrost Schedule (estimated every 5 months or as needed)
Annual -80 C Defrost Crew
Shireen, Isis, Michael R.
How It Works
Ice builds up in the -20 C freezer and periodically the freezer needs to be completely defrosted so that the condenser unit does not shut down and items can be retrieved efficiently. Keep in mind the rate of ice build up correlates with how long the door is left open as we go into and out of the unit. During a freezer defrost responsibilities include moving all items from the main unit to the smaller units in the laboratory (late afternoon), turning off the unit and leaving the door open to melt out ice build up (overnight), once all the ice has melted turning the unit back on and allowing it to come to temperature (morning-afternoon), returning all items to the unit in their original locations (late afternoon). Note that, organizational items such as metal freezer shelving units should not be moved to the smaller units and can be left out at room temperature during the thaw. Before a freezer defrost all researchers should make an effort to consolidate their items into as few labeled boxes as possible. Any small tubes left out of boxes are likely to be lost during the transfers. During the thawing portion of the defrost it is important that the members in charge of the defrost try to mop up the water from the floor as it collects and place bins in appropriate areas to collect as much of the water as possible.