Amberwood Senior Apartments in Daly City, California, is a 130-unit complex built in 1970. In 2017, with help from the Bay Area Multifamily Building Enhancements (BAMBE) program, Amberwood launched an initiative to reduce overall energy costs by 15% or more. BAMBE provided a rebate of $750 per unit — a total of $97,500 — to help pay for the improvements.

The BAMBE program is a service offered by the Bay Area Regional Energy Network, a collaboration of public agencies representing all nine counties in the San Francisco Bay Area. BAMBE’s consultants identified numerous areas where energy efficiency could be improved:

• The two central water heaters weren’t operating at the highest efficiency, and one even had a failed flue damper;
• 60% of the windows were of the single-glaze metal frame variety used in the initial construction;
• Indoor common areas had compact fluorescent lighting;
• Exterior lighting was a combination of compact fluorescent, inefficient candescents, and high-pressure sodium lamps; and
• Many units had inadequate insulation of the attic cavity.

Amberwood replaced the two 500,000-Btu gas water heaters with two Cyclone Mxi 300,000-Btu gas water heaters that met the project’s desired thermal efficiency of 96% and provided demand-controlled recirculation.

A.O. Smith Cyclone® Mxi condensing water heaters are available from 120,000-500,000 Btuh and all deliver thermal efficiencies of 95% and higher. The unique helical coil heat exchanger limits weld joints for optimal service life while maximizing heat transfer.

Cyclone units offer advanced electronic control with built-in diagnostics, and they’re network-ready for remote monitoring. Modulating models adjust the firing rate to specific demand, further increasing savings.

“Amberwood really liked the fact that the Cyclone units dropped them from 1 million to 600,000 Btu while improving efficiency,” said Richard Gutierrez, CEO, J.J. Commercial Water Heaters, the company that installed the Cyclone units and still maintains the property. “A.O. Smith was the only company that could help us.”

“The Cyclone condensing water heaters have performed well, and we’ve had lower energy bills since 2017,” said Edgar Tividad, facilities manager, Amberwood.

In addition to the water heating upgrade, Amberwood replaced 103 single-pane windows with dual-pane vinyl frame models, upgraded the lighting to LED in each unit and the common area, properly insulated attic cavities, installed low-flow aerators on kitchen and bath faucets in all units, and installed low-flow showerheads.

The entire upgrade at Amberwood achieved far more than the original goal of 15% energy savings. The comparison before and after the renovation shows a 25% overall energy savings — a total reduction of 607 million Btu, 28,530 kWh, and 52.3 metric tons of CO2 emissions.

The Amberwood upgrade is a good example of how private housing can achieve much higher energy efficiency when aided by government-sponsored programs that offer generous rebates and bring energy consultants on-site to conduct audits and make recommendations.