It's the flooding problem most of all. I'm in one of the few Manhattan co-ops that still allows washing machines and dryers and it's a wonderful thing to have it in my apartment. But many landlords, co-op board and condos don't permit them because of the flooding.
A couple of my friends and I made hot ice for our school science fair. We used sodium acetate. This project won first place at my schools science fair!!! Materials: Stove. Pot. A spoon. A glass cup. and Sodium acetate (you can find it online or in certain heat packs). How to do it: You heat water in a pot and put the sodium acetate in the water.
Make sure to follow all dry ice safe handling precautions. Fill a metal or plastic container half full of hot water and add a few pieces of dry ice every 5-10 minutes. As the water cools, you will need to add more hot water to maintain the fog effect. As a rule of thumb, one pound of dry ice will create 2-3 minutes of fog effect.