This standard applies to sensible-heat-type thermal energy storage devices in which a transfer fluid enters the device through a single inlet and leaves the device through a single outlet. Storage devices having more than one inlet and/ or outlet may be tested according to this standard@ but each flow configuration involving a single inlet and single outlet must be tested separately. This standard is not applicable to those configurations in which there is simultaneous flow into the storage device through more than one inlet and/or simultaneous flow out of the storage device through more than one outlet. The transfer fluid can be either a noncondensing gas or a liquid. This standard does not include factors relating to cost@ life@ reliability@ or the consideration of requirements for interfacing with specific heating and cooling systems. The test procedure and equipment outlined in this standard are most easily adaptable to devices used to store thermal energy on the order of 107 Btu (1010 J) or less. PURPOSE The purpose of this standard is to provide a standard procedure for determining the thermal performance of sensible thermal energy storage devices used in heating@ airconditioning@ and service hot water systems.