This measure requires installing an ENERGY STAR-certified HPWH with an integrated tank to serve a commercial space. It applies to both existing buildings and new construction, provided a HPWH is not mandated by local code. In addition to efficiency requirements, the ENERGY STAR specification is restricted to units with rated maximum power draw of at least 12 kW and tank volume of at most 140 gallons.
The RTF has separate UES measures for residential water heaters in commercial applications and for unitary commercial water heaters with plans to develop a measure for larger commercial split/built-up systems in the future. In all cases, there is savings uncertainty due to variations in water heater technology, water usage patterns, distribution losses, and other factors.