Residential-type
water heaters, pool heaters, and unfired water heater storage
tanks shall comply with the minimum performance
requirements specified by federal law.
Unfired storage water heating equipment shall have a heat loss through the tank surface area of less than 6.5 British thermal units per square foot hour [Btu/(ft2•h)] (20.5 W/m2). (ASHRAE 90.2:7.1]
Unfired storage water heating equipment shall have a heat loss through the tank surface area of less than 6.5 British thermal units per square foot hour [Btu/(ft2•h)] (20.5 W/m2). (ASHRAE 90.2:7.1]