Concrete wall sealing

[Timr]

I am a mechanical engineer (HVAC) and have an issue related to a project I am working on that I am looking for advise on. A local museum of natural history has a large storage room where artifacts are kept. One wall is an outside wall, the others are interior. All walls and the floor are concrete. Humidity control in the room is critical. I would like to recommend a liquid sealant that will either waterproof or nearly waterproof the walls. Any suggestions?
Thanks in advance,
Timr