SoCalGas Joins the California Energy Commission in the Demonstration of a New Ultra-Efficient Water Heater and Space Cooler Developed by Stone Mountain Technologies
GTI is leading the study of a high efficiency, ultra-low NOx technology that can provide hot water and space cooling simultaneously

LOS ANGELES, March 12, 2019 /PRNewswire/ -- Restaurants use a lot of energy to not only prepare and cook food, but to cool kitchens, dining rooms, and other spaces. A new high efficiency, ultra-low emissions commercial water heating and space cooling unit, which begins field demonstrations at two Southern California restaurants this week, could dish out energy savings, lower operating costs, and reduce greenhouse gas emissions for foodservice and hospitality facility operators.

The new technology uses a thermally driven heat pump fueled by natural gas or propane to capture ambient energy, achieving a heating efficiency of 140 percent or greater. It is projected to reduce energy use by 30 to 50 percent compared to standard natural gas water heaters. The highly-efficient heat pump also provides space cooling simultaneously, which reduces the need for air conditioning and can help lessen electricity use. 

Stone Mountain Technologies, Inc. (SMTI) developed the new heat pump by redesigning heat pump technology traditionally used for cooling and focusing it on heating with cost-effectiveness and scalability in mind. GTI is leading the demonstration, and AO Smith Corporation is also providing support. Project funding was awarded by the California Energy Commission and Southern California Gas Company (SoCalGas) research and development funds authorized by the California Public Utilities Commission.

"SoCalGas is pleased to support the development of this novel heat pump technology, which will be especially beneficial for the foodservice industry," said Yuri Freedman, senior director of business development at SoCalGas. "This single system, efficiently and with very low NOx emissions, provides hot water for washing dishes and air conditioning to cool off warm kitchens and leads to increased energy bill savings."

Unlike other electrically-driven heat pump systems that use environmentally damaging hydrofluorocarbons, the new heat pump's ammonia/water refrigerant has zero ozone depletion and zero global warming potential. It was recently certified as Ultra-Low NOx per South Coast Air Quality Management District requirements.

SoCalGas has been a leader in the research and development of new technologies that increase energy efficiency, reduce air pollution and greenhouse gas emissions, and keeps bills affordable for customers. In the last five years alone, SoCalGas energy efficiency programs have saved more than 146 million therms, enough to power 326,000 households a year, and have reduced emissions by an amount equivalent to taking 165,000 passenger cars off the road.

SoCalGas' vision is to be the cleanest natural gas utility in North America, delivering affordable and increasingly renewable energy to its customers. Earlier this month, SoCalGas announced a bold plan to replace 20 percent of its traditional natural gas supply with renewable natural gas by 2030.

"The Energy Commission is proud to work with researchers throughout the state and invest in innovative technologies that can help lower energy costs for ratepayers while reducing greenhouse gas emissions," said Laurie ten Hope, deputy director of the Energy Commission's Energy Research and Development Division.

"With nearly 90,000 restaurants in California, this emerging product could enable the proliferation of Zero Net Energy Restaurants," said Paul Glanville of GTI and principal investigator of the project. "We are fortunate to have an exceptional team on this project, with active support from our manufacturing partners, our research partners, a very capable installation contractor, and two great host sites, and we look forward to measuring system performance in the field."

SMTI will continue to pursue efforts to commercialize this water heating and space cooling unit after the demonstrations have been completed and the results analyzed.

"Already, we have strong interest from major manufacturers of HVAC equipment who would buy the core part of the technology from us, and then finish it into final products," said Michael Garrabrant, president of SMTI. "By offering Thermal Compressors for sale, our business model is to leverage the strengths of existing original equipment manufacturers and to help them quickly and easily get to market with a new and highly efficient heating technology offering for their customers."

About the California Energy Commission
The California Energy Commission is the state's primary energy policy and planning agency. It has seven core responsibilities: advancing state energy policy, encouraging energy efficiency, certifying thermal power plants, investing in energy innovation, developing renewable energy, transforming transportation, and preparing for energy emergencies.

About GTI
GTI is a leading research, development, and training organization that has been addressing global energy and environmental challenges by developing technology-based solutions for consumers, industry, and government for more than 75 years. 

About SoCalGas
Headquartered in Los Angeles, SoCalGas® is the largest natural gas distribution utility in the United States. SoCalGas delivers affordable, reliable, clean and increasingly renewable natural gas service to 21.8 million customers across 24,000 square miles of Central and Southern California, where more than 90 percent of residents use natural gas for heating, hot water, cooking, drying clothes or other uses. Natural gas delivered through the company's pipelines also plays a key role in providing electricity to Californians— about 45 percent of electric power generated in the state comes from gas-fired power plants.  

SoCalGas' vision is to be the cleanest natural gas utility in North America, delivering affordable and increasingly renewable energy to its customers. In support of that vision, SoCalGas is committed to replacing 20 percent of its traditional natural gas supply with renewable natural gas (RNG) by 2030. Renewable natural gas is made from waste created by dairy farms, landfills and wastewater treatment plants. SoCalGas is also committed to investing in its natural gas system infrastructure while keeping bills affordable for our customers. From 2014 through 2018, the company invested nearly $6.5 billion to upgrade and modernize its natural gas system to enhance safety and reliability. SoCalGas is a subsidiary of Sempra Energy (NYSE: SRE), an energy services holding company based in San Diego. For more information visit or connect with SoCalGas on Twitter (@SoCalGas), Instagram (@SoCalGas) and Facebook.  

About Stone Mountain Technologies, Inc.
Based in Johnson City, Tennessee, SMTI has been developing and perfecting a cost-effective and scalable design for Thermally-Driven Heat Pumps since 2009.  The approach re-configures an age-old thermodynamic cycle into high-efficiency replacement products for furnaces, boilers, and hot-water heaters in homes and light commercial buildings.  The company is commercializing several HVAC products with OEM partners, and also significant support from utilities and other energy efficiency stakeholders.  SMTI's approach offers the most economically practical method to decarbonize building heat loads on a large scale, a major source of green-house gases and other pollutants.  More information at and on LinkedIn at

About Southern California Gas Co.: Southern California Gas Co. (SoCalGas) has been delivering clean, safe and reliable natural gas to its customers for more than 145 years. It is the nation's largest natural gas distribution utility, providing service to 21.6 million consumers connected through 5.9 million meters in more than 500 communities. The company's service territory encompasses approximately 20,000 square miles throughout central and Southern California, from Visalia to the Mexican border. SoCalGas is a regulated subsidiary of Sempra Energy (SRE), a Fortune 500 energy services holding company based in San Diego.


SOURCE Southern California Gas Company

For further information: California Energy Commission: Michael Ward, 916-654-4989,; or GTI: Diane Miller, 847-768-0683,; or SoCalGas: Irene Nguyen, 213-244-2442,; or Stone Mountain Technologies, Inc: Scott Reed, 818-421-4229,