This standard is to cover the test procedures and methodology for determining the energy efficiency of self-contained portable electric spas and hot tubs. This standard has been updated as a result of input from the California Energy Commission (CEC) and members of the International Hot Tub Association (IHTA). The update includes new formulas to calculate Allowable Standby Power, including inflatable spas, and new labeling requirements. This is a printed version. A downloadable PDF version is also available in the PHTA Store.