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Phase Change Matters Newsletter Dec 16 2019

The Phase Change Matters e-mail newsletter is a weekly summary of the latest news and research on phase change materials and thermal energy storage. To subscribe, visit For more frequent updates, follow @puretemp on Twitter or visit the Phase Change Matters blog,


Sunamp’s UniQ heat storage product earns RAL certification 

The RAL Quality Association PCM has awarded the RAL Quality Mark to Sunamp Ltd. for its UniQ line of thermal batteries.

RAL quality markThe product, which has been installed in thousands of homes across Europe, uses a specially formulated phase change material to store large amounts of energy from renewable and other sources and release it as heat to deliver hot water and space heating as needed. The PCM is sodium acetate trihydrate-based with a patented formulation giving a melt point of 58 degrees Celsius. 

In independent testing conducted by ZAE Bayern, the PCM was successfully melted and solidified in a UniQ heat battery for 10,000 cycles. At the end of the test, no significant differences in stored thermal energy capacity were found between the cycled samples and an uncycled sample of the PCM. The product, which also passed leak testing, earned the association’s highest level of certification, Grade A. 

Over 3,000 UniQ units are now in service, with Sunamp projecting a tenfold growth in sales next year. The quality mark will be featured on Sunamp’s website and in other marketing materials, UniQ manuals and product labels.

“We are delighted that our thermally charged UniQ product range of heat batteries has been awarded a globally recognized mark of quality,” said Kate Fisher, Ph.D., a materials integration scientist at Sunamp, which is based in Edinburgh, Scotland. “RAL certification is a huge accolade and cements Sunamp’s position as world leaders at the forefront of the technology.”

Sunamp UniQ heat batteriesThe RAL Quality Association PCM was established in 2004 to develop standards for the PCM industry. Members include Axiotherm, Microtek Laboratories, Rubitherm, Croda Europe, va-Q-tec, PCM Technology, Global-Systems Europe, Sasol, Sunamp, Pluss Advanced Technologies and PureTemp LLC.

Members and non-members alike can submit their products to the association for independent testing and earn the RAL Quality Mark. To qualify for the mark, products and materials must meet standards for energy storage capacity and phase transition temperature and stability, as defined in RAL-GZ 896.

“I am delighted that more and more products with PCM technology can be awarded the RAL Quality Mark as meaningful and transparent proof of quality and longevity,” said Stefan Thomann, the association’s managing director. “The great thing about Sunamp’s UniQ heat batteries is that they can be installed and used in homes very easily and save a lot of energy costs and reduce carbon emissions immediately. The fact that they passed more than 10,000 cycles make sure that users will be able to profit from these benefits for decades.”


Agenda set for Swiss symposium on thermal energy storage

The agenda is confirmed for the 7th Swiss Symposium Thermal Energy Storage, to be held in Lucerne, Switzerland, on Jan. 24, 2020. Here are some of the speakers and topics:

• “Thermal Energy Storage: Status and Importance in the Energy System,” Gennady Ziskind, Ben Gurion University, Israel

“Seasonal Thermal Storage: Focus study of the Forum Energiespeicher Schweiz,” Michel Haller, HSR Rapperswil, Switzerland

• “The effects of climate change on heating and cooling demand,” Matthias Berger, Hochschule Luzern – Technik & Architektur, Switzerland

• “Sensible and latent storage integration for large-scale electrothermal energy storage,”  
 Emmanuel Jacquemoud, MAN Energy Solutions, Switzerland

• “Compact Thermal Energy Storage for Industrial Refrigeration Processes,” Maurizio Zaglio, Sunamp Ltd., United Kingdom

• “The assessment of seasonal thermal energy storage: status and challenges,” Zhang Xiaojin, Paul Scherrer Institut, Switzerland

The registration fee is 300 Swiss francs. Lunch, snacks and beverages are included.


Energy efficient greenhouse

Ceres greenhouse patent drawingU.S. patent application 20190373820 (applicant Ceres Greenhouse Solutions LLC, Boulder, Colorado):

“A greenhouse, for cold weather climates, is configured with a gable that is offset toward the north wall and therefore the south extension of the roof, from the gable to the south wall is longer than the north extension. A greater amount of light can enter through this south extension and the inside surface of the north wall is configured with a reflective surface to allow light to be more uniformly distributed around the plants. … The north wall of an exemplary greenhouse, may comprise a phase change material that absorbs heat during the daylight hours and then emits heat into the greenhouse during the night to moderate the temperature of the greenhouse.”

System for transporting fragile objects

U.S. patent application 20190367242 (applicant The Supporting Organization for the Georgia O’Keeffe Museum, Santa Fe, New Mexico):

“[A] vibration-isolating system comprises a platform adapted to carry one or more loads and an adjustable load-positioning system. The platform is suspended within a support structure by a plurality of isolators. The isolators are tuned to impede vibrations in a pre-determined frequency range for a payload having a pre-determined mass. … In certain embodiments, case may include one or more environmental buffers. Examples of environmental buffers include thermal buffers (such as insulation layers or thermal phase change tiles) and humidity buffers (such as conditioned silica gel tiles).”

Other recent patent applications:

Apparatus for filling heat storage material (applicant HLB Life Science Co. Ltd. (Gyeonggi-do, South Korea)

Self pressurizing bladder tooling (applicant Sikorsky Aircraft Corp., Stratford, Conn.)

Climate-control system having pump (applicant Emerson Climate Technologies Inc., Sidney, Ohio)

Optimization of building heating and cooling systems (applicant Greensleeves LLC, Findlay, Ohio)

Humidification-dehumidification desalination system (applicant King Fahd University of Petroleum and Minerals, Dhahran, Saudi Arabia)

PCM-treated fabrics (applicant Crypton Inc., Bloomfield Hills, Mich.)

Thermochromic liquid crystal temperature indicator (applicant Prasidiux LLC, Arlington, Virginia)


• Presentations given at the 14th Conference on Advanced Building Skins in Switzerland in October are available via download for 80 euros. Among the topics: “Thermal performance of engineered wood flooring impregnated with phase-change materials,” Damien Mathis, University LAVAL, Fontenay-sous-Bois, France; “Thermal comfort modelling and its impact on building energy performance,” Vikram Sami, Olson Kundig, Seattle, Wash.; and “Integrated solar electric/thermal cooling system with storage,” Mohannad Bayoumi, King Abdulaziz University, Jeddah, Saudi Arabia.

Loughborough University researchers have been awarded funding to help with the design and development of a four-wheeled electric vehicle for research, teaching and outreach in India. Engineers at Vellore Institute of Technology and PSG College of Technology, both located in Tamil Nadu, will work with Loughborough researchers to explore the use of phase change material and other technologies to manage battery heat. The high ambient temperatures in south India and similar climates can significantly reduce battery life in electric vehicles.  

• Energy storage specialist 1414 Degrees has announced plans to acquire SolarReserve Australia II, which owns the Aurora Solar Energy Project in South Australia and two solar sites in New South Wales. The Adelaide, Australia, company plans to use the Aurora site to build a 400 MW solar farm with thermal storage capacity of several thousand megawatt hours. The technology stores electricity as thermal energy by heating and melting containers full of silicon.

• Agritech startup Ecozen of Pune, India, which makes portable solar cold rooms for use on small farms, has raised a total of $6 million to fuel its growth phase. The cold rooms feature a PCM-equipped thermal storage unit that can store power for more than 36 hours in case of cloudy or rainy weather.  

Advanced Cooling Technologies Inc. of Lancaster, Penn., is seeking qualified research and development engineers at various experience and education levels to work on space, defense and energy-related applications. 

• Andreas Hauer, head of the energy storage department at ZAE Bayern (the Bavarian Center for Applied Energy Research) has joined the board of directors at the International Solar Energy Society.


For our full list of recent academic research, see Here are highlights from the past week:

From Solar Energy Materials and Solar Cells:

Fatty amines as a new family of organic phase change materials with exceptionally high energy density
A new low-cost high-temperature shape-stable phase change material based on coal fly ash and K2CO3

From Journal of Cleaner Production:

Consistent preparation, chemical stability and thermal properties of a shape-stabilized porous carbon/paraffin phase change materials
Performance and optimization of a novel active solar heating wall coupled with phase change material

From Journal of Thermal Analysis and Calorimetry:

Study on a novel solid–solid phase change materials: solvent-free preparation, thermal properties and phase separation behaviors

From Materials Today: Proceedings:

Phase change materials in concrete: An overview of properties

From IOP Conference Series: Materials Science and Engineering:

Application of kulkote temperature regulating phase change material on merino wool fiber and pashmina wool felt material
Performance analysis of the solar photovoltaic thermal system using phase change material

From Polymers:

Novel Bio-Based Pomelo Peel Flour/Polyethylene Glycol Composite Phase Change Material for Thermal Energy Storage

From International Journal of Heat and Mass Transfer:

Thermal characterization of a heat exchanger equipped with a combined material of phase change material and metallic foams

From Applied Thermal Engineering:

Modelling, simulation and comparison of phase change material storage based direct and indirect solar organic Rankine cycle systems
Hybrid thermal management of a Li-ion battery module with phase change material and cooling water pipes: An experimental investigation
Experimental investigation of a tank-in-tank heat storage unit utilizing stable supercooling of sodium acetate trihydrate

From Journal of Building Engineering:

Thermal and sound properties of concrete mixed with high porous aggregates from manufacturing waste impregnated with phase change material

From Energy and Fuels:

Preparation and thermal properties of microencapsulated polyurethane and double-component polyethylene glycol as phase change material for thermal energy storage by interfacial polymerization

From Energy:

Performance Improvements in Solar Flat Plate Collectors by Integrating with Phase Change Materials and Fins: A CFD Modeling
Quantitative evaluation of thermal performance and energy saving potential of the building integrated with PCM in a subarctic climate
Carbon black nano particle loaded lauric acid-based form-stable phase change material with enhanced thermal conductivity and photo-thermal conversion for thermal energy storage

From Solar Energy:

An experimental investigation of composite phase change materials of ternary nitrate and expanded graphite for medium-temperature thermal energy storage
Exergy-based optimisation of a phase change materials integrated hybrid renewable system for active cooling applications using supervised machine learning method

From Thermochimica Acta:

Critical review on measured phase transition enthalpies of salt hydrates in the context of solid-liquid phase change materials

From Renewable Energy:

Design of sensible and latent heat thermal energy storage systems for concentrated solar power plants: Thermal performance analysis
Fabrication of a novel nano phase change material emulsion with low supercooling and enhanced thermal conductivity

From Applied Energy:

Development of an Energy Efficient Extrusion Factory employing a latent heat storage and a high temperature heat pump

From Construction and Building Materials:

Preparation of low-temperature composite phase change materials (C-PCMs) from modified blast furnace slag (MBFS)

From Energy and Buildings:

Performance assessment of residential building envelopes enhanced with phase change materials
Form-stable phase change material based on fatty acid/wood flour composite and PVC used for thermal energy storage
Optimal design of a thermal energy storage system using phase change materials for a net-zero energy Solar Decathlon house

From Materials Chemistry and Physics:

Microencapsulated phase change material suspensions for cool thermal energy storage
Shape-stabilized phase change material/nylon composite based on recycled diatomite

From ASHRAE Journal:

Evolution of Thermal Energy Storage for Cooling Applications


Connect with PCM experts and industry leaders on LinkedIn

More than 1,500 people have joined a LinkedIn group devoted to the discussion of phase change material and thermal energy storage. The Phase Change Matters group is an interactive complement to the award-winning blog and newsletter of the same name.

You are invited to join the group and connect with PCM and TES experts from around the world. In the past six weeks we welcomed many new members, including Bruno Buracchio, international accounts manager at Eutecma GmbH, Mannheim, Germany; Lixin Cheng, associate editor at Heat Transfer Engineering, Sheffield, United Kingdom; Hazhir Fatahi, Ph.D. candidate in mechanical engineering at Université de Sherbrooke, Quebec, Canada; Steve Marquis, incident manager at American Express, Phoenix, Arizona; William Inman, architectural engineer at Sunamp Ltd., Edinburgh, United Kingdom; and Nidhi Sharma, master’s degree candidate at the University of British Columbia, Canada.