The Chicago Plumbing Code

§ 18-29-505


§ 18-29-505.1 Unfired vessel insulation.

Unfired hot water storage tanks shall be insulated so that heat loss is limited to a maximum of 15 British thermal units per hour (Btu/h) per square foot (47 W/m2) of external tank surface area. For purposes of determining this heat loss, the design ambient temperature shall not be higher than 65F (18.3C). Any ASME stamp or other required indication markings shall remain exposed.