Efficient electric water heaters in multifamily buildings significantly reduce carbon emissions

Efficient electric hot water heating technologies significantly reduce the carbon emissions of multifamily buildings, according to a report by the American Council for an Energy-Efficient Economy (ACEEE) and New Buildings Institute (NBI).

In multifamily buildings with five or more units, water heating uses more energy than space heating, cooling, or lighting, the report says. Converting gas-fired water heaters to advanced technology—electric heat pump water heaters (HPWHs)—would cut greenhouse gas emissions from water heating by an average of 58%.

If HPWHs are powered entirely by clean sources, they cause zero emissions, making them a critical tool for decarbonizing the economy. Efficient electric water heaters carry a higher upfront cost over gas models, so policymakers would have to provide incentives to owners to make the conversion, the report says.

“Many utilities offer incentives for building or unit owners to install in-unit heat pump hot water heaters,” an ACEEE/NBI news release says. “Yet few programs are designed specifically for multifamily buildings, which offer unique challenges.”

New York City has two very large buildings dedicated to answering the 911 calls of its five boroughs. With more than 11 million emergency calls annually, it makes perfect sense. The second of these buildings, the Public Safety Answering Center II (PSAC II) is located on a nine-acre parcel of land in the Bronx. It’s an imposing 450,000 square-foot structure—a 240-foot-wide by 240-foot-tall cube. The gleaming aluminum cube risesthe equivalent of 24 stories from behind a grassy berm, projecting the unlikely impression that it might actually be floating. Like most visually striking structures, the building has drawn as much scorn as it has admiration.