I am trying to determine the heat loss from an insulated tank. The insulation is calcium silicate with a 2.5" thickness. The tank construction is cyllindrical 14' ID, 24' ht, carbon steel construction with 0.5" thickness. The product is 50% NaOH, so the idea is to use an electrical heater external to the tank to maintain product temp 80-100F to prevent it from freezing in the winter months. Any help would be greatly appreciated, I have looked everywhere and can't seem to find the help I need.