Yep, I agree. The steep drop off with the dry ice was likely after it dissipated, and the air temp recovered. The question then would be, when to drain the water though.
I'd add a drain in a bottom corner to allow drainage as it melts. I think the temp in the dry ice container would remain lower if there were enough thermal mass, too.
Have you ever played with dry ice? I just read of someone using it to remove old tile and mastic from a concrete floor. There was also an article on another site describing a city dropping chunks into rat holes to kill rat nests.
Have you ever played with dry ice? I just read of someone using it to remove old tile and mastic from a concrete floor. There was also an article on another site describing a city dropping chunks into rat holes to kill rat nests.