To comply with DOE's Zero Energy Ready Home program, all installed water heaters and fixtures must meet certain efficiency criteria.
Water heaters and fixtures in single-family homes and in multifamily dwellings with their own independent water heater shall meet the following efficiency criteria:
- Gas water heaters, if present, shall have an Energy Factor ≥ 0.90 or a Uniform Energy Factor ≥ 0.87.
- Electric water heaters, if present, shall have an Energy Factor ≥ 2.2 or a Uniform Energy Factor ≥ 2.2.
- All showerheads and bathroom sink faucets shall be WaterSense labeled.
- The hot water distribution system shall store no more than 1.2 gallons between the hot water source and the furthest fixture. This shall be verified by either 1) a calculation using the piping or tubing interior diameter and the system length based on plans, or 2) by a field verification test, using the protocol described in Endnote 15, which demonstrates a minimum temperature rise of 10 °F by the time 1.4 gallons of water is delivered to the furthest hot water fixture.
These provisions do not apply to multifamily buildings with central hot water delivery systems. Multifamily projects must satisfy the Efficient Hot Water Distribution provision instead (see Endnote 15).
The following Solution Center guides provide more information about water heaters, showerheads and bath faucets, and plumbing distribution systems:
Heat Pump Water Heaters
Guide providing information about heat pump water heaters.
Ground-Source Heat Pumps
Guide providing information about ground-source (geothermal) heat pumps including an overview of technology and guidance on compliance and installation.
Gas-Fired Tankless Water Heaters
Guide describing how to install a tankless hot water heater in a new or existing home to provide domestic hot water that is heated on demand without the standby losses associated with tank storage water heaters.
Guide describing gas-fired boilers and hot water heat distribution systems used for home heating.
Showerheads and Faucets:
Guide describing how to install WaterSense® labeled showerheads.
Guide describing how to install WaterSense® labeled bathroom faucets and accessories.
Hot Water Distribution:
Guide describing effective ways to distribute hot water using either a core (compact) plumbing layout or a central homerun manifold piping system.
Guide describing the use of recirculation pumps to speed the flow of hot water to faucets for reduced wait times and savings in energy and water usage.