Tonnage of Imeco Evaporator?

Hi,
We are having all kinds of issues with blast freezing products. Works great one day, terrible the next. Temperatures are great, air is great. Even have two different pallets in the same tunnel that are 35 degrees apart.
I'm trying to be more scientific so I'd like to get the tonnage on some of our units. Right now I'm looking for info on an Imeco BFX3827-102 Serial Number 1936-1RH4.
If anyone could provide any insight I would really appreciate it.

Thanks in advance.

Peter