Home builders and remodelers who install large capacity water heaters (greater than 55 gallons) need to be aware that revised federal energy standards that go into effect in April 2015 are expected to have a significant impact on space requirements for these water heaters and on the way they are installed.
Smaller water heaters must also comply with the increased energy-efficiency requirements and are expected to be more costly as a result. However, they are not expected to have additional space and/or venting requirements like the larger capacity units.
The revised standard was imposed by the Department of Energy and will go into effect following a five-year transition period to allow manufacturers to gear up for production of the more efficient units. As of April 2015, manufacturers will no longer be allowed to construct water heaters not meeting the new requirements, but builders and remodelers will still be able to install the existing stock.
Water heaters that comply with the new energy-efficiency standard are expected to be more costly and bulkier than current models. In particular, some current models of large capacity electric water heaters may no longer be available because the higher energy factor standards will require heat pump water heater technology. This new technology requires the water heater to be installed in an area with sufficient household air volume for heat exchange.
Builders and remodelers whose projects include installation of large capacity gas-fired water heaters must accommodate the positive pressure venting needs of higher efficiency gas- or propane-fired units during installation. And remodelers and home owners replacing a water heater may also find that these bulkier large capacity water heaters are too large to fit into the existing space and/or require new exhaust venting. According to DOE’s market assessment, about 4 percent of gas-fired storage water heater shipments and about 9 percent of electric storage water heater shipments fall into the large-volume water heater category.
In preparation for the new energy-efficiency standard, builders and remodelers who routinely install large capacity water heaters are encouraged to reach out to manufacturers for details about availability and space and venting requirements. NAHB will continue to follow this issue and will provide members with information about installation and potential alternatives to the larger capacity units as it becomes available.