All knowledge is contained etc...
So, I'm looking for a thermal mass to use as a moderator for my fanless (or minimal fan use) computer setup. What I'm thinking is a water volume of around 18 litres (0.085 kilowatts x 2 hours = 0.17 kwh, or ~146173 calories. Mass of water needed in kg = 146.173 / ∆T. In this case 8 K, gives ~18.27 kg. Water weighs ~1 kg per liter.). Ideally this would be in a thermally conductive watertight container with a flat bottom, approximately rectangular, with dimensions of >9" (~22 cm) on one side x >16" (~33 cm) another side x >13"(33 cm) tall. Since this is going to be on a wheeled cart, a container with tight lid would be a definite plus, though I could move them separately if it came to that. If it weren't for the last part, the obvious thing would be some kind of unusually tall aluminum baking pan. If anything comes to mind that would suit, I'd be interested to know. Glass or plastic containers are easier to find, but they're poor heat conductors. I could stack a whole bunch of soda cans, but the contact area would be significantly reduced.