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.
To melt, the ice, the heat pump takes heat from the house to heat the outdoor coils. This reduces average heat pump efficiency. Supplemental Heat. As it gets colder outside, the heat pump provides less heat. Yet the house needs more heat to keep comfortable. At some outdoor temperature it will be too cold for the heat pump to provide all the heat the house needs.