re. dimensions: it is shaped like a cylinder, height is 16.25 or 16 1/4 in and diameter is 18in (top or bottom) -- just measured it, to be sure; u can install it at a slight angle to make it fit - it would not hurt it..
re. voltage: this is a 120V, but if u need 220, i think u just need to replace the heating
unit - u might find that at a hardware
store; i've researched it sometime ago, and if u need more info, pls let me know..
converting it from 120V <=> 220V should be simple, as the electrical
part is comprised of only heating
element & thermostat..