Ionocaloric Heat Pumps for Zero-GWP Heating
Calion Technologies, Inc.
Recipient
Danville, CA
Recipient Location
9th
Senate District
16th
Assembly District
$154,063
Amount Spent
Active
Project Status
Project Update
In 2025 the project has advanced from early subsystem development into deeper experimental validation and prototype integration. Over the past year, the team expanded physics-based modeling and material/system down-selection to guide the overall architecture, while iterating on key hardware such as the electrochemical separator, heat exchangers, and pressure/flow-handling components. In parallel, the automation and controls effort matured from initial concepts into a functioning control platform with integrated sensing and flow routing, enabling more repeatable experiments and higher-quality performance data.
The team is now focused on improving robustness and buildability while completing end-to-end system integration. Key near-term priorities include streamlining assembly and quality control, resolving remaining procurement/lead-time constraints, and hardening the prototype for longer-duration operation. Looking ahead, efforts will center on integrated performance testing under closed-loop control, iterative optimization of operating conditions and interfaces between subsystems, and preparing the core components for scale-up and a representative system-level demonstration.
The Issue
Electrification is one of the most promising and scalable solutions to decarbonize building energy, and its’ decarbonization must focus on (1) Improved heating efficiencies and (2) using lower GWP energy sources through electrification and (3) lower GWP refrigerants/materials. Although direct electrification of the heating demand through resistive heating can provide cleaner energy and lower GWP materials, its operation is expensive and will require significant renewable energy generation capacity. Heat pumps, on the other hand, have the potential to meet both efficiency and clean generation goals.
Project Innovation
The major technical hurdles heat pumps must overcome for deployment in the heating of commercial buildings is low heating efficiency. Heat pumps must compete with natural gas heaters both in capital and operational costs. Unfortunately, the operational costs tend to dominate in commercial buildings, so achieving price parity with natural gas heaters is determined directly by the efficiency of the heat pump and current pricing in the energy markets. Until heat pumps can improve their performance, natural gas heaters will simply make more economic sense due to the current favorable energy economics for natural gas. Improving heat pump efficiency for the heating of commercial buildings is non-trivial. Low efficiency is caused by: (1) Heating/Cooling load mismatch, and (2) High expansion and compressor losses due to high pressure ratios needed for large temperature span operation. Moreover, they face all these problems using very high GWP refrigerants, such as R410a or R134a.
We propose a novel, non-vapor compression-based technology that has the potential to circumvent all the above problems and meet the performance goals laid out by the CEC. Our ionocaloric heat pump is a water and salt-based heat pumping technology with high efficiencies over very-high temperature spans. It utilizes the ionocaloric effect by changing the concentration of a salt in a mixture to modulate a material’s melting point and therefore heat content. We’ve defined the ionocaloric effect as a thermal response to an applied electrochemical field (i.e., ionic field). Ionocaloric heating/cooling utilizes the ionocaloric effect within an appropriate thermodynamic cycle (e.g., Reverse Stirling cycle). Ionocaloric cooling can utilize any phase transition that the material may go through in response to an ionic field.
Project Goals
Project Benefits
This project is expected to demonstrate the feasibility of ionocaloric heat pumping as a zero-GWP alternative to conventional vapor-compression systems for California buildings. Planned outcomes include an integrated prototype that combines electrochemical separation, heat exchange, controls, and thermal storage to provide efficient heating, cooling, and dehumidification under simulated operating conditions. The project is intended to validate key performance metrics, reduce technical uncertainty around system integration and controls, and generate data needed for future scale-up and commercialization. If successful, the technology could enable lower-emissions space conditioning and water-heating solutions while improving load flexibility and reducing peak electricity demand. The work will also support development of manufacturable designs and application-specific product concepts for residential and light commercial markets.
Affordability
Typical vapor compression units manufactured are for ~$150/kW. The ionocaloric heat pump is targeting a low $50/kW manufacturing cost to reduce capital expenses. Its high efficiency, COP>3.2, lowers energy consumption & cuts operational costs. Built-in thermal storage enables load shifting & reduced peak demand charges. High-GWP refrigerant elimination avoids regulatory costs while making heating & cooling more accessible, sustainable, and cost-effective
Equity
The ionocaloric heat pump project advances equity by providing a cost-effective, high-efficiency heating and cooling solution that reduces energy costs for low-income communities. By eliminating high-GWP refrigerants, it improves indoor and outdoor air quality, benefiting public health. Its thermal storage supports affordable renewable energy use, ensuring access to clean, reliable heating and cooling for all communities.
Key Project Members
