Nothing is perfectly closed. Back when dtr worked in a computer shop, she would get big desktops with closed loop water cooling, it would run out after about three years, so the smart thing was to bring it to the shop annually and let them break the seal, flush and refill the water, and then reseal.
Now, coincidentally enough, dtr now is employed by a company that installs networking at data center sites, so she works alongside IREN people and sees the similarity to the water cooling computers, only on a more massive scale.
Yes. That was my point.
If you tell people it is a closed loop and after they find out it isn't really they are going to believe you lied to them.
The people you are talking to are not tech experts, they will believe that what you say is what you mean. Tell them that it is a closed loop when it is not and someone like me can come along and point out that it is not a closed loop they are not going to believe a thing you say from that point forward.