Hi

I am working on a site. it is a brand new built building. The building is now coming near the end of its complateion and will soon be handed over to the customer. i am commissioning a close control AC unit within the comms room in the basement of this building. I have set my humidity setpoint to 45%, my low alarm sepoint is 30% and my high is 70%. the humidity in this room seems to fluctuate alot and doesnt remain consistent at its setpoint. The comms room isnt live yet so there isnt much of a load in the room.

The supplier of the unit has told me that due to it being a newly built building and te fact that there is no real load in the room, the unit will not be able to maintain consistent humidity levels at 45% and that the RH reading will fluctuate.

My question is if anyone would know, why would this be the case? how could the fact it is a newly built building affect my RH reading? and how could no load in the room affect my rh reading?