Freezers require an underfloor heating system as explained above or the frost will heave the concrete. Either a radiant system (typically operates at 60F) or an underslab ventilation system, either forced or gravity.
If you are using standard AC units forget the ACH calculation and base the CFM on the load calc. The ACH calc has nothing to due with the heat gain into and within the room.
I've designed ammonia refrigeration systems that have valve tags...one thought I've been kicking around is the use of RFID tags to store the information on the valve itself in addition to the valve number. Anyone doing this?