Panasonic Corporation, Osaka Gas Co., Ltd., and its subsidiary Daigas Energy Co., Ltd. have jointly developed what they describe as the industry's first* absorption chiller compatible with co-firing of hydrogen and city gas. The new system supports a hydrogen/city gas co-firing ratio from 0% to 100%, and existing city gas-fueled chillers can be upgraded for hydrogen use by replacing key components.
The absorption chiller, developed and sold by Panasonic, uses water as a refrigerant and is designed to operate using gas and waste heat as energy sources. According to Panasonic, the system has been used for over 50 years and holds a significant share of the Japanese market**. The updated chiller technology enables users to reduce CO₂ emissions without replacing the entire unit, aligning with efforts to support decarbonization.
To address hydrogen’s high flame temperature and combustion speed—factors that contribute to increased NOx emissions—the three companies have implemented a hydrogen/city gas dual-use burner and a combustion control unit. This configuration allows the system to maintain NOx emissions below 40 ppm while achieving efficient energy performance.
Daigas Energy, with decades of experience in combustion technologies for city gas systems, contributed to the burner development. The companies report that the new burner and control unit allow stable performance across all co-firing ratios and cooling/heating outputs, minimizing exhaust heat loss and maintaining low NOx levels.
“Even if a customer currently selects an absorption chiller that operates on city gas, when the customer decides to use hydrogen fuel in the future, the unit can be converted to be compatible with hydrogen fuel through a simple replacement and addition of parts,” the companies stated.
*As of August 7, 2025. Claimed by Panasonic and Daigas Energy
**Estimate based on data from the Japan Refrigeration and Air Conditioning Industry Association
