Hello,
I am looking for other labs who have these -80 freezers. Our unit was installed in 2021 with little issues, however we have just discovered that our rack robot inside the -80 portion is frozen in place. After chatting and working with the Field Engineer, we will have to thaw the -80 to a point where our collection can be removed and still be frozen. Then begin the process of bring it to room temp, free the rack robot, dry it, and then bring it back down to -80 for at least 24hrs. Right now, our collection is being held hostage until we get this all done and could be compromised in the process.
We are thinking that our lab humidity is too high in general. Granted this year has been a standout for humidity even for a MN summer, so there is that, but if you have these units in your labs:
- Do you have the freezer in its own temp/humidity-controlled space?
- What are you doing to control the humidity entering the -80 portion from the access module.
- We have the recommended nano air dryer for the purging steps, but do we need something additional?
- Do you change the purge time for the access module depending on the season?
- How do you alleviate the chances of this becoming a regular occurrence?
TIA and any insight on this would be greatly appreciated!
The air that passes through your Nano dryer is bleeding into the SAM at a pretty slow rate, so it’s possible that if there is a lot of atmospheric air exchange, (i.e. during very heavy use periods with lots of samples moving in and out) you aren’t purging that wet air fast enough.
As long as the dryer is doing what it’s supposed to be doing, there isn’t much you can do to speed this process up to my knowledge. Do you have a way to check the %RH of the incoming air? Has it been serviced recently?
The only other alternatives I can think of would be either working with your facility team to wrangle in the humidity in your lab (my guess is this is what Hamilton will suggest), or limiting the amount of samples coming in and out of the system at one time.
Fortunately I’m using a -20 system, and so far haven’t had many issues though we do get a bit of frost if lots of samples are moving in/out through the entry module. This always dissipates within an hour or so.
Let us know if you figure anything out!
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@desert_platypus Thanks for your reply!
Currently to my knowledge we do not have a way to monitor or check the %RH of the incoming air before the nano dryer. I am working with the facilities folks on seeing if we can get something installed and to find out when the last PM was on the dryer we have at the supply end. We are also working with them to get an idea of what is the humidity in the lab and if we have any levers to pull to rein it in to a more acceptable amount if it is too much.
Since the only entry place for the humidity is the access module’s inner door to the -80, Hamilton believes this is the cause. Hamilton thinks that it could be that the access module cap/closure might not be making a good seal when it closes. They also think that we could increase the amount of air purge time before opening the -80 portion from that point as well to reduce the moisture getting inside. This is a possibility, but it already takes much longer than folks want to open, close, and introduce the racks as it is so I might get some push back from the rest of the operators.
As it is now, I will have to wait until our MN winter to start putting the racks back into the freezer and the rate of those going back in is going to be much slower than before. I will have to limit how many I can introduce per week. This is something I do not want to have to repeat in a year or two as a maintenance item. 
hahaha.