Cool Gas Defrost

[Fire and Ice]

Hi everyone. I am working on a masterbuilt commercial freezer. It has a cool gas defrost. Does anyone have any ideas why there may be such a large amount of frost on the ceiling by the evaporator? Everything seems to be sealed well and the door is tight. I havent really gotten into it yet, but I suspect the unit is in defrost too long. any suggestions? Thanks - Jed

[chemi-cool]

Frost on the ceiling is from air entering. Replace the door gasket. Look for other places where air can enter.

Cool gas defrost or hot gas defrost?

[R. skiffington]

You could also have a problem with the insullation integrity of the coolroom panel, if there is moisture in the panel it will stay at room temp, when the evap goes into defrost and steam is released it will re-condense and freeze on the coldest area close to the unit in your case the ceiling. But at the end of the day the moisture has to be coming from outside the freezer, maybe a plastic air curtain would help.