What guidelines do engineers use to determine if a xfomer will be hung above the ceiling or floor mounted? Do any code issues dictate this? Small offices in retail stores or schools often end up with a floor mounted "heated table" (as I call them)and are very hot and noisy rooms as a result. The old answer (teach it the words) to the often asked question "How can I get that thing to stop humming?" is not well recieved.