The current cooling mechanism
Currently, the freezer is cooled by two systems, the freezer and the vacuum. The air from the vacuum is cooled in two stages, once in the heat exchanger, and then more though the cold box/reservoir.
The freezer is not strong enough to counteract the cold loss alone, using the the vacuum that we use now. If we were to implement a closed loop system with an external motor, it might be enough.
The vacuum solution had a problem with humidity, the continuous addition of humidity during cooling lead to the pipes clogging. Removing/minimizing the humidity could solve the issue.
Possible improvements
Closed loop air flow system
Having the entire air flow being integrated into the freezer in a closed loop system will make it be continuously cooled by the freezer as it flows. Additionally it will remove a lot of moisture from the air in the closed system.
Return to the MR Core Labs clamping method
Using the clamping solution currently in place would remove this issue, as there would probably be no need for adding more cold air, since none is drawn out.
Metal pipes
Switching out our plastic tubes with metal pipes would drastically increase the thermal transfer rate. There is a machine to bend pipes that are the approximate size at TrollLabs. Kim used them for his chair.
Nitrogen
At MRCL, there is nitrogen available in pipes. This could be used to pump into the freezer to replace potential air pumped out by the vacuum clamping system. This makes it so that no condensation enters the freezer, reducing the amount of frost buildup.
One backdraw to this is that nitrogen could replace the air in the room, leading to choking. Therefore, the whole system could have to be placed in a ventilation chamber. This has to be checked with the people at MRCL.