I tried hot and cold water in my poly ice trays side by side. Same source, same trays, same time in the fridge. The cold froze faster, so my water obviously isn't college-level engineering material. :confused2:
Mom's old single-door refrigerator had the aluminum 'box' for frozen food, whose coils were in the thin walls of that 'ice box', and that had to be defrosted every few weeks. METAL trays, if filled with warm water, could melt through the frost until they contacted the conductive metal of the box & inner coils. Those trays froze faster with their metal to metal heat conduction. Mine DID NOT, so they're just plain dumb.
Now that we've thoroughly debunked those utter fakes "Adam and Jamie(?)" let's one-up them by proving once and for all that the earth is indeed flat. Imagine them saying a .50 BMG bullet won't travel 3' under water, when we know water won't even slow it down.
"Seeing is believing." (inventor of CGI)
I had a mixing valve on a stool a few houses ago. Such a thing IS a 'check valve', and when it stuck open we'd get a spurt of hot from sink or tub before pressure balanced and cold flowed steadily. I found and deleted it when I remodeled. A thick tank cozy minimized condensation after that. Now, many 3.8L-flush closets have ~1" of EPS lining to do that.
