Rubitherm commercializes PCM module for ventilation systems

Rubitherm Technologies of Germany has developed a PCM storage device designed for use in domestic ventilation systems. The PhaseCube reduces energy costs by storing the “cool” of nighttime air for use during the heat of the day. The first commercial installation was in a single-family home in Berlin in December 2020.

Dr. Esther Kieseritzky, Rubitherm’s general manager, answered questions about the new product by e-mail.

Q: How the product was developed?

Rubitherm's PhaseCubeA: “The core of the product is the compact storage module, which was developed by Rubitherm quite some time ago. The decision to offer not just the panel but a ready-to-be-installed component for controlled domestic ventilation arose two years ago. At that point we had already a five-year prototype installation in our offices to prove the concept of cooling the CSM panels during the night to provide comfortable indoor temperatures during the day. In the last year we ran many tests on size, shape, volume flow, temperature inputs to define our basic model for the PhaseCube: the box containing 10 CSM panels.”

Q: Is the PCM paraffin or biobased?

A: “We are mostly using salt hydrates in this application to lower the fire hazard and maximize storage capacity per volume.”

Q: Is subcooling/hysteresis an issue with this PCM?

A: “The standard product in this application – SP21 – has a small hysteresis. For this reason night air has to be at least 19°C or lower. Subcooling is not an issue at this quantity level.”

Q: Has the product been fire tested?

A: “CSM panels inside the PhaseCube have been fire tested for the salt hydrate PCMs SP21 and SP25 and received an A1 fire rating. The housing is made of standard expanded polypropylene.”

Q: Is there any third-party research supporting the product’s performance data?

A: “Some of our first clients did in-house lab testing but there is no published data from third parties.”

Q: Are 2021 sales projections available?

A: “We plan to have the first 3,000 units installed by the end of the year. Current focus is on Germany, Austria and Switzerland. We are open to distributors and partners in other countries.”


Vapor compression apparatus

U.S. patent application 20210041146 (applicant Sunamp Ltd., Edinburgh, Scotland): 

“The present invention describes a vapour compression apparatus wherein an intermediary located heat battery is capable of releasing charge (i.e. discharging) and/or charging and thereby controlling the temperature of a heat source or heat sink temperature in a vapour compression cycle. More particularly, the present invention describes vapour compression apparatus wherein an intermediary located heat battery comprising Phase change material (PCM) is capable of releasing charge (i.e. discharging) energy and/or charging and thereby controlling the temperature of a heat source and/or heat sink temperature in a vapour compression cycle in a range of refrigeration and/or heating systems including: air conditioning in both domestic and industrial uses; transportation of food/materials in vehicles, trains, air, etc. The present invention also relates to a methodology for selecting phase change materials (PCMs) and/or refrigerants for a vapour compression apparatus.”

Temperature regulating pad wrap

Pad wrap patent drawingU.S. patent application 20210041147 (applicant Gentherm Inc., Northville, Mich.): 

“A heating and cooling device is disclosed comprising at least one integral low voltage heating and cooling source and an efficient flexible heat distribution means having a thermal conductivity of from 375 to 4000 W/mK for distributing the heat and cool across a surface. Further aspects include thermal interface compounds to provide full thermal contact as well as the use of a phase change material to provide a long lasting heating and/or cooling effect without the use of external electrical input. Preferred applications include automotive and furniture seating heating and cooling, along with outdoor garments having distributed heating and cooling effects. Additional aspects include a thermal pad wrap and a thermally conductive liquid system for heat/cool distribution.”

Computer room heat-pipe air conditioning system

U.S. patent application 20210045265 (applicant Changsha University of Science and Technology, China): 

“A computer room heat-pipe air conditioning system with an emergency cooling control method. The system comprises a phase-change energy storage module, a phase-change material packaging body, a condenser housing, a condenser, a cold releasing pump, evaporators, evaporation fans, four three-way valves, a cooling unit, standby power generators and storage batteries. The three-way valves are opened and closed based on a preset heat-pipe cooling criteria in combination with phase-change energy storage technology.”

System for transporting fragile objects

U.S. patent application 20210039866 (applicant Supporting Organization for the Georgia O’Keeffe Museum, Santa Fe, N.M.): 

“According to certain embodiments, 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. The adjustable load-positioning system is adapted to facilitate positioning the one or more loads such that the payload having the pre-determined mass is centered at the center of gravity of the platform.”

More U.S. patent applications:

Optics and structure for space applications (Trans Astronautica Corp., Lake View Terrace, Calif.) | Electric vehicle thermal management system for hot climate regions (Pranav Vikas (India) Pvt. Ltd.) | Methods and devices for selective disruption of visceral fat by controlled cooling (General Hospital Corp., Boston) | Infusion set having reduced patient pain (Leif Bowman, San Diego, Calif.) | Heat exchange system (Active Energy Systems, Knoxville, Tenn.) | Solar cooking apparatus (Sunphase AS, Oslo, Norway) | Rapid fill compressed gas storage tank (TDA Research Inc., Wheat Ridge, Colorado) | Cyclone cooler device (General Electric Co., Schenectady, N.Y.)


•  The U.S. Department of Energy has announced up to $100 million in funding for transformative clean energy technology research and development via ARPA-E’s OPEN 2021 funding opportunity. Concept papers are due April 6. Applications should address the potential impact of the proposed technology on the agency’s mission areas: reducing imported energy, reducing energy-related emissions, and improving energy efficiency.

• Scientists from the National Renewable Energy Laboratory say they have developed a simple way to evaluate the potential of novel materials to store or release heat on demand in a way that more efficiently manages a building’s energy use. The paper, “Rate Capability and Ragone Plots for Phase Change Thermal Energy Storage,” describes a new method of optimizing thermal storage devices that mirrors an idea used for batteries.

• The hot-rock thermal energy storage system developed by Siemens Gamesa Renewable Energy has attracted unexpected interest from heavy industry. The system was designed to store electricity in the form of heat, for later conversion back to electricity. But the cement, aluminum, steel, paper and chemicals sectors are looking at the system to replace the coal and gas they use.

Butter at room temperatureCanadian foodies have been complaining for weeks that their butter no longer softens at room temperature. The dairy industry says the claims are unfounded, but independent experts point to increased use of palm fat in cow feed as a likely culprit. The BBC reports that hundreds of farmers around the country have stepped up their use of palm oil substances to meet increased demand for butter during the pandemic. So why is the butter harder? “To explain it simply,” writes Dr. Sylvain Charlebois of Dalhousie University in Nova Scotia, “palm oil given to dairy cows increases the proportion of saturated fat in milk compared to unsaturated fat, thus increasing the melting point of butter.”

Peli BioThermal is partnering with temperature-controlled packaging experts to offer a free webinar series focusing on best practices in clinical and commercial supply chain management. In the first InnovationShare webinar on March 4, Bernard McGarvey of Parenteral Supply Chain Inc. will review a process that includes gathering a set of temperature profiles, reviewing the profile data, analysis of the thermal challenge and the dips and spikes of the profile.

• The open-access journal Energies has announced plans to publish a special issue focusing on recent approaches to the modeling and simulation of thermal energy storage systems for different built environmental applications including water and space heating, waste heat utilization, cooling and air conditioning. The guest editors for the issue, “Modelling and Simulation of Thermal Energy Systems,” are Dr. Philip Eames and Dr. Mohamed Sakr Fadl of Loughborough University. The deadline for manuscript submissions is Sept. 30, 2021.

• The U.S. Food and Drug Administration has approved Pfizer‘s application for a change in policy that allows its coronavirus vaccine to be transported and stored in ordinary freezers. The change allows for vaccine vials to be stored at -25°C to -15°C (-13°F to 5°F) for up to two weeks as an alternative or complement to storage in an ultra-low temperature freezer.

• Thermal energy storage specialist Malta Inc. of Cambridge, Mass., has raised $50 million in a Series B funding round led by Switzerland-based methanol and ammonia producer Proman. Malta is a start-up incubated at X, the Moonshot Factory of Google’s parent company Alphabet Inc. Malta’s pumped heat energy storage system converts electricity from any source, to be stored as thermal energy. It is capable of satisfying a daily or weekly load cycle by efficiently storing up to 200 hours of energy, Malta says.

Princeton University‘s Andlinger Center for Energy and the Environment is seeking applicants for a postdoctoral research associate position focused on high-temperature energy storage and heat-transfer media for concentrated solar power. 

• The INPATH-TES network, coordinated by the University of Lleida, offers dozens of online courses likely to be of interest to readers of this newsletter. The courses, worth 1-4 ECTS credits, include “Thermophysical Properties: DSC, TGA, T-History and Other Homemade Techniques,” “Heat Transfer Fundamentals” and “Integration of PCMs into Building Envelopes and Thermophysical Considerations.” Enrollment costs vary.


From Journal of Building and Engineering:

Microencapsulated bio-based phase change material-micro concrete composite for thermal energy storage

From Materials Today: Proceedings:

Microencapsulated phase change materials as slurries for thermal energy storage: A review

From Journal of Energy Storage:

Incorporation of phase change materials in an expanded clay containing mortar for indoor thermal regulation of buildings
Preparation and effective thermal conductivity of a Paraffin/ Metal Foam composite
Improvement of photocells by the integration of phase change materials and thermoelectric generators (PV-PCM-TEG) and study on the ability to generate electricity around the clock
Analysis and optimization of triple tube phase change material based energy storage system
Thermally recyclable polyester-based phase change materials networks with high latent heat and network self-stability even at high temperature

From Solar Energy Materials and Solar Cells:

Freeze-cast form-stable phase change materials for thermal energy storage

From Applied Sciences:

Towards Phase Change Materials for Thermal Energy Storage: Classification, Improvements and Applications in the Building Sector
On the Energy Performance of Micro-Encapsulated Phase Change Material Enhanced Spackling with Night Ventilation

From International Journal of Thermal Sciences:

Investigation of the effect of thermal resistance on the performance of phase change materials

From AIP Conference Proceedings:

A review on methods of preventing super cooling in phase change materials (PCMs)

From Energy and Buildings:

Parametric study on the thermal performance of phase change material-assisted earth-to-air heat exchanger
Enhanced thermophysical properties of organic PCM through shape stabilization for thermal energy storage in buildings: A state of the art review

From Applied Materials & Interfaces:

Cellulose Nanofibrils Endow Phase-Change Polyethylene Glycol with Form Control and Solid-to-gel Transition for Thermal Energy Storage

From Journal of Molecular Liquids:

Microencapsulated heptadecane with calcium carbonate as thermal conductivity-enhanced phase change material for thermal energy storage

From Materials for Thermochemical Energy Storage:

Integrating Mobile Thermal Energy Storage (M-TES) in the City of Surrey’s District Energy Network: A Techno-Economic Analysis

From Journal of Renewable and Sustainable Energy:

Microencapsulated paraffin as a phase change material with polyurea/polyurethane/poly(lauryl methacrylate) hybrid shells for thermal energy storage applications

From Applied Thermal Engineering:

Empirical validation and comparison of methodologies to simulate micro and macro-encapsulated PCMs in the building envelope

From Molecules:

Degradation of Fatty Acid Phase‐Change Materials (PCM): New Approach for Its Characterization

From Journal of Nanoscience and Nanotechnology:

Gypsum Composite Boards Incorporating Phase Change Materials: A Review

From Thermal Science and Engineering Progress:

Numerical Analysis of an Automobile Cabin Thermal Management using Passive Phase Change Material

From 14th International Renewable Energy Storage Conference:

A Comparison Study of Sensible and Latent Thermal Energy Storage Used in Domestic Hot Water Solar Heating System
Development of Phase Change Materials Based on Mixtures of Salt Hydrates Through Theoretical Prediction and Experimental Investigation

From Nature Energy:

Rate capability and Ragone plots for phase change thermal energy storage

From Fullerenes, Nanotubes and Carbon Nanostructures:

Expedited energy charging of water using natural graphite flake for cool thermal storage

From Journal of Power Sources:

Development of the inorganic composite phase change materials for passive thermal management of Li-ion batteries: Application


Connect with PCM experts and industry leaders on LinkedIn

LinkedIn logoMore than 1,500 people have joined a LinkedIn group devoted to the discussion of phase change material and thermal energy storage. You are invited to join the Phase Change Matters group and connect with PCM and TES experts from around the world. 

This month we welcome Simon Ströder, head of mechanical engineering at Tec4med Lifescience GmbH, Darmstadt, Germany; Charles Ikutegbe, Ph.D. candidate at the University of Auckland, New Zealand; Roger Zimmermann, product development engineer at Cowa Thermal Solutions AG, Lucerne, Switzerland; Dr. Kaniz Ronak Sultana, author and researcher, Canada; Steve Yeager, formulation development and production lab manager at American Thermal Instruments, Dayton, Ohio; Mohamed Katish, chemical technician at Sunamp Ltd., Edinburgh, Scotland; Michael Tenbrock, global director of technology research and development at Baltimore Aircoil Co., Columbia, Maryland; and Swati Agarwala, research scholar at National Institute of Technology Karnataka, India.


Does your company, agency or university have a job opening, new research, new product or other news you’d like to share? I would love to hear from you. Please contact newsletter editor Ben Welter at benedict.welter@gmail.com.


RAL Quality MarkThis newsletter is made possible through the generous support of the RAL Quality Association PCM and the members listed below. To learn more about the association, including membership benefits, please contact Stefan Thomann, executive director, at info@pcm-ral.de.  

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