: OK, I'm not sure why you put the cooling coils under the ice
: sculpture. Seems like you would get a much better cooling job
: with the coils mounted near the top of the box.

I whole heartedly agree, but one of the downsides of working with conceptual artists is that they are very particular about what they want. In this case three stainless pedestals with transparent display boxes on the top. Nothing of the refrigeration system is to be visible, and the works should be able to be viewed from all sides, and above. The sculptures are 'life-casts', so a silicone mold of a head, filled with a mixture of blood and slightly saline water, frozen and then removed from the mold before being displayed in the freezers.

For added difficulty points, they need to maintain a frozen state for up to 6 months at a time, be able to handle a full melt-down without letting the blood mixture run all over the gallery floor, and do it all as quietly as possible in temperatures up to 25C.

It's fair to say that there have been more than a few challenges along the way!

No wedding theme anywhere near unfortunately.. This work is about blood quantum - the dilution of indigenous blood, and how that affects cultural identity.

: Can you put in a dessicant to absorb any moisture? If the air is
: dry there won't be significant humidity to form your ice
: crystals.

I did consider a dessicant, but couldn't see how it would keep working once the moisture it had already absorbed froze. The big problem we had last time around was that the refrigeration plant wasn't keeping up with the waaay out of spec gallery conditions (26-27C 85% humidity with hot lighting) and the sculpture was getting slushy on the top, evaporating, and then there's no end of water vapor looking for somewhere to freeze. As soon as the channels close up, there's no air circulation, and the problem is compounded. The channels are 3mm wide slots around all four sides of the plate. If we can keep the ice below -9C, then there will be no vapor, but that's proved a bit of an ask given the other constraints.

: Minus 15 C works out to 5 degrees F. Not sure if you know that the
: Fahrenheit scale is based on a solution of equal weights of salt
: and ice.

I did not know that!

Thanks for the suggestions - I'll keep them in mind if we have problems this time around. We made a number of changes to the systems prior to shipping them off to the next gallery, so hopefully the refrigeration plant can keep on top of things this time.

Simeon.