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The award-winning Phase Change Matters blog tracks the latest news and research on phase change materials and thermal energy storage. E-mail tips and comments to Ben Welter, communications director at Entropy Solutions. Follow the blog on Twitter at @PureTemp. Subscribe to the weekly PCM newsletter. Or join the discussion on LinkedIn.

Two Entropy advisors, Dr. Mohammed Farid and Lucas B. Hyman, are pleased to take your questions about PCMs and thermal energy storage. Send your questions to We'll select the best and post the answers here each week.




Research roundup: Refrigerated container envelope with PCM; paraffin-polystyrene mixe; thermal performance of air-PCM unit; more

Ben Welter - Tuesday, May 31, 2016

A refrigerated container envelope with a PCM (Phase Change Material) layer: Experimental and theoretical investigation in a representative town in Central Italy [Energy Conversion and Management]

Diffusion and thermal conductivity of the mixture of paraffin and polystyrene for thermal energy storage: A molecular dynamics study [Journal of Energy Institute]

Experimental study on the thermal performance of air-PCM unit [Building and Environment]

An experimental study of the latent functionally thermal fluid with micro-encapsulated phase change material particles flowing in microchannels [Applied Thermal Engineering]

Patent application: Devices comprising a heat source material and activation chambers

Ben Welter - Friday, May 27, 2016

U.S. patent application 20160146506 (applicant British American Tobacco, London):

Patent drawing of tobacco device"A device is provided comprising a heat source material which is a phase change material and which undergoes an exothermic phase change upon activation by an activating agent to generate heat, a heat source chamber holding the heat source and an activation chamber providing the activating agent, and a barrier separating the interior of the heat source chamber from the interior of the activation chamber, wherein the activation chamber is deformable and wherein deformation of the activation chamber causes rupture of the barrier to allow contact between the activating agent and the heat source material. Embodiments also provide an activation chamber for use in the device and comprising an activating agent to trigger activation of a heat source material."

Patent application: Solid state solar thermal energy collector

Ben Welter - Friday, May 27, 2016

U.S. patent application 20160146507 (applicants Richard Lee Johnson, Suffolk, Va.; Braden Eric Hines, Pasadena, Calif., et al):

"A system for receiving, transferring, and storing solar thermal energy. The system includes a concentrating solar energy collector, a transfer conduit, a thermal storage material, and an insulated container. The insulated container contains the thermal storage material, and the transfer conduit is configured to transfer solar energy collected by the solar energy collector to the thermal storage material through a wall of the insulated container."

Research roundup: Shape-stabilized PCM in wallboards; modeling thermal comfort; mortar and concrete with PCM; more

Ben Welter - Thursday, May 26, 2016

Energy performance of double shape-stabilized phase change materials wallboards in office building [Applied Thermal Engineering]

A simple model for automatic analysis and diagnosis of environmental thermal comfort in energy efficient buildings [Applied Energy]

Modeling the Heat Transfer Coefficient Between a Surface and Fixed and Fluidized Beds With Phase Change Material [Journal of Heat Transfer]

Evaluation of the application of Phase Change Materials (PCM) on the envelope of a typical dwelling in the Mediterranean region [Renewable Energy]

Properties of cementitious mortar and concrete containing micro-encapsulated phase change materials [Construction and Building Materials]

Experimental research on a novel energy efficiency roof coupled with PCM and cool materials [Energy and Buildings]

Sonoco ThermoSafe shares sneak preview of new Certis Platform shipper line

Ben Welter - Thursday, May 26, 2016

Certis Platform preview video

Sonoco ThermoSafe has posted a video preview of its new line of universal shipping solutions. The Certis Platform, coming in July, is designed to optimize warehouse space, reduce inventory costs, simplify training and increase productivity. Only three types of PureTemp phase change material and eight shippers are needed to create 24 shipping solutions across temperature ranges and duration.

PCM briefing; Tariff relief for U.S. chemical producers; registration open for green chemistry conference in Portland

Ben Welter - Wednesday, May 25, 2016

• Legislation signed into law this week by President Obama will provide tariff relief to U.S. chemical producers that import raw materials and intermediate products. “With 80 percent of specialty chemical manufacturers importing raw materials for which there is no domestic source, this bill is a huge deal,” said William E. Allmond IV, vice president of government and public relations at the Society of Chemical Manufacturers & Affiliates.

• The global thermal energy storage market will top $3 billion by 2023, according to a report published by Market Research Engine, “Global Thermal Energy Storage Market by Technology for Commercial and Industrial, Utilities, and Residential End Use Applications – Trends and Forecast 2016-2023.” 

Arsenal's new jerseyArsenal has unveiled new uniforms for the 2016-17 soccer season. The Puma jerseys feature ACTV Thermo-R technology. Strategically placed tape infused with microencapsulated phase change material absorbs excess heat and releases it back to the body when needed.

• Registration is open for the Green Chemistry and Engineering Conference June 14-16 in Portland, Ore. The theme for the 20th annual conference is "Advancing Sustainable Solutions by Design." Technical session topics include sustainable materials, chemical manufacturing processes, next-generation catalysis and chemical building blocks.    

Allen Yun, formerly director of strategic initiatives for OPTUM, is joining Pelican BioThermal as director of global services

• A survey suggests that many U.S. companies will not meet OSHA's new hazard communication standards on time. The deadline for compliance is June 1.

More than 8.1 million people worldwide are now employed by the renewable energy industry, up 5 percent from last year, the International Renewable Energy Agency says.

• The Environmental Protection Agency's chemical data reporting rule brings challenges and opportunities, writes James G. Votaw, a partner with the law firm Manatt, Phelps & Phillips. The next CDR reports, covering chemical manufacture and import activities during the period 2012-2015, must be submitted to the EPA by Sept. 30. 

Research roundup: Form-stable hydrogel; copper foam/paraffin; review of PCMs for thermal energy storage; more

Ben Welter - Wednesday, May 25, 2016

Preparation and properties of a form-stable phase-change hydrogel for thermal energy storage [Applied Polymer Science]

Analytical study of heat generation effects on melting and solidification of Nano-Enhanced PCM inside a horizontal cylindrical enclosure [Applied Thermal Engineering]

Heat transfer enhancement of phase change composite material: Copper foam/paraffin [Renewable Energy]

Thermal energy storage for low and medium temperature applications using phase change materials – A review [Applied Energy]

Influence of phase change material on mechanical and thermal properties of clay geopolymer mortar [Construction and Building Materials]

Numerical model and simulation of a solar thermal collector with slurry Phase Change Material (PCM) as the heat transfer fluid [Solar Energy]

Research on Temperature Dependent Effective Thermal Conductivity of Composite-Phase Change Materials (PCMs) Wall Based on Steady-state Method in a Thermal Chamber [Energy and Buildings]

PCM 2016 conference papers available for download

Ben Welter - Wednesday, May 25, 2016

The International Institute of Refrigeration has posted more than two dozen papers presented at the PCM 2016 conference in Karlsruhe, Germany, earlier this month. The downloads are available for 15 euros each. A few highlights:

Passive cooling potential of two different PCM cooling ceilings in the energy efficiency center, (H. Weinlader, F. Klinker, M. Yasin)

"In the Energy Efficiency Center – the new R&D building of the ZAE Bayern - two different PCM cooling ceiling types are installed and monitored in two office rooms. The ceilings are connected to a water circuit and can be used for heating or cooling. The PCM ceilings are prototypes which differ in the positioning of the PCM layer: ceiling type 1 with the PCM on top of and ceiling type 2 with the PCM below the water pipes. It was found, that cooling ceiling type 2 had a better thermal connection between PCM and room, nevertheless, the passive cooling power of the two different system designs was quite similar when measured as a function of the room globe temperature."

Experimental analysis on a novel air heat exchanger containing PCM in a cold room, (B. Copertaro, R. Fioretti, P. Principi)

"An air heat exchanger consisting of aluminium containers with finned surface filled with PCM (5 °C melting temperature) was located near the evaporator of a cold room. The aims are to reduce cooling energy consumption and improving the maintenance thermal conditions of stored products. For this purpose, an experimental campaign was carried out and a monitoring system was developed. The cold room thermal behaviour, with and without PCM, was studied under steady state operating conditions. As expected a reduced number of on/off compressor cycles (6 cycles instead 13 cycles) in the PCM added cold room was observed. Test results showed that by storing PCM in the air heat exchanger, up to 16% of energy saving can be achieved."

Standardization of PCM characterization via DSC, (S. Gschwander, T. Haussmann, G. Hagelstein)

"This work investigates the influence of particle size on crystallization behaviour of microencapsulated and emulsified n-octadecane using differential scanning calorimetry (DSC) and laser diffraction. Analyses of microcapsules show a stepwise decrease of nucleation temperature (from 26 °C to 14 °C) with decreasing particle size (from 300 μm to 3 μm). Further reduction of particle size in emulsions (< 0.2 μm) results in a slight decrease of nucleation temperature (<2 °K)."

Potential use of phase change materials in a display cabinet: development of a dynamic modeling approach, (H.M. Hoang, F. Raoult, D. Leducq)

"Different configurations (position of the PCM in the equipment) are simulated and discussed: after the evaporator and under shelf. At first, the modelling of a display cabinet in a transient state is developed based on a simplified heat transfer model using zonal approach. By combining it with a melting and freezing process of PCM units located inside the display cabinet, the effects of the PCM addition on air and food temperatures are simulated. Placing the PCM under shelves allows maintaining the product temperature during defrosting or electricity shortage."

A case study on the application of phase-change materials in buildings, (A. Hantsch)

"Energy storages employing the phase-change enthalpy of some material yield much larger energy densities than specific-heat-based systems. This case study is about the effect of phase-change materials on the heat and cooling load and annual energy demand for various scenarios. By means of a TRNSYS model it is possible to carry out energetic annual simulations. The results of this contribution allow giving advice for the design of new systems."

Experimentation for the evaluation of aluminum foams for improving heat transfer in PCM thermal storages, (R. Lazzarin, S. Mancin, M. Noro)

"This work investigates the use of Aluminum foams as heat transfer medium to improve the overall heat transfer of paraffin waxes that can be possible PCMs to be implemented in hybrid sensible-latent water TESs. The design of a new experimental testing rig is here presented together with some preliminary simulation results obtained during the phase change process of paraffin waxes with melting temperatures around 45 °C, with and without metal foams, in a water thermal storage unit." 

Latent heat storage with polyethylene enhanced with aluminum stripes, (T. Ozcan, E. Gukelberger, M. Kauffeld)

"Using a built prototype latent heat storage integrated into a solar air conditioning system at the Institute of Refrigeration, Air Conditioning, and Environmental Engineering’s test facility loading and discharging tests were conducted to investigate the use of PCM materials in a heat exchanger of a solar system to support steam production in cloudy periods. The latent heat storage concept is designed for the temperature range to 130 °C."

Comparison of a single stage and a multistage latent heat storage for domestic hot water delivery, (J. Diriken, J. van Bael, F. Leemans)

"In this paper we assess the potential to use multiple PCM in combination with a compact heat exchanger for direct domestic hot water delivery purposes for e.g. district heating substations. The results of the measurements on a compact thermal energy storage device based on multiple phase change materials with different melting temperatures are compared to a geometrical identical system with a single PCM with one melting temperature." 

For a full list of papers, go to Type Karlsruhe in the first search box, check "Conference papers" and type 2016 in the box next to "Year."

Research roundup: PCM gypsums with improved fire response; bio-inspired composites; analytical solutions to Stefan problem

Ben Welter - Monday, May 23, 2016

Use of multi-layered PCM gypsums to improve fire response. Physical, thermal and mechanical characterization [Energy and Buildings]

Novel Photodriven Composite Phase Change Materials with Bioinspired Modification of BN for Solar-Thermal Energy Conversion and Storage [Journal of Materials Chemistry A]

Analytical solutions to the Stefan problem with internal heat generation [Applied Thermal Engineering]

PCM briefing: Cold Chain Global forum agenda is set; deal reached on overhaul of TSCA

Ben Welter - Friday, May 20, 2016

The full agenda has been released for the 14th Cold Chain Global Forum to be held Sept. 26-30 in Boston. Sponsors and exhibitors include Pelican BioThermal, va-Q-tec AG, Cold Chain Technologies, American Aerogel, RGEES and Sonoco ThermoSafeFrank Butch, director of engineering at ThermoSafe, will lead a master class on temperature assurance packaging certification. Conference registration is open, with early bird rates available through June 3. [pdf]

• U.S. House and Senate negotiators have agreed on a bill overhauling the 40-year-old Toxic Substances Control Act. Under the compromise version, EPA regulations would pre-empt most new state regulations, although states could still enact measures such as monitoring and labeling of chemicals, the New York Times reports.

• In a piece on the importance of cocktail ice, Primer magazine offers a unique description of how water freezes and melts: "The two ideas that help us understand the changes in water jumping between a solid and liquid state are enthalpy and entropy. Which I like to oversimplify and think of as order and disorder, enthalpy being order and entropy being the little shit disturber that lets it all go to hell. Enthalpy wants to freeze your ice and entropy wants to melt it, neither one of them ever really completely win this battle but who reigns over the other at any given time is decided by temperature: If the temperature is at -5°C/23°F enthalpy has the upper hand, if it’s 20°C/60°F then it’s entropy’s ball game."