Bahnhofstr. 31
07607 Eisenberg
Tel.: +49 (0) 36691 53 118
Fax: +49 (0) 36691 53 120


With its leading competence in thermal energy storage solutions, AXIOTHERM enables industry and service companies to benefit from increased efficiency and effectiveness offered by PCM (Phase Change Materials). Offering extensive experience in development and application planning, AXIOTHERM is a manufacturer and expert partner for leading companies, and your specialist for cost-efficient systems based on approved macro encapsulations.

Axiotherm PCM

The Axiotherm Phase Change Materials are designed to absorb and release large quantities of thermal energy at constant temperatures. Over 30 organic (ATP) and inorganic (ATS) high-performance PCM in a temperature range between -40 °C to 120 °C. Upon request further melting temperatures can be developed for specific applications!

Axiotherm PCM are preferably available in special macro-encapsulated form with an optimized surface-to-mass ratio for faster energy exchange and improved performance in practical applications. Standardised solutions such as our HeatSel®s and HeatStaxx® are available for water and air-based applications and can be adapted to your specific requirements.

HeatSel® – Energy Storage Solutions for water-based applications

Specifically developed for water-based applications, HeatSel® is a high performance macro encapsulation based on customized and blow molded synthetic material. The macro encapsulation design allows for a combination of a large surface and the smallest possible PCM layer thickness enabling the entire PCM module to run through the phase change process. This leads to high efficient heat transfer (quick charge and discharge) even at very low temperature variations. The signature shape ensures that each module (also within stacks of macro encapsulated modules) fully passes the water while optimally using the available space.

The PCM capacity as well as its discharging and charging performance should be precisely adjustable to a defined temperature level across a large range to turn it into an highly effective element of complex systems such as technical facility structures when used as part of latent storage solutions. Therefore HeatSels® are used within a heat carrier medium (e.g. water) which results in an excellent heat transfer from the heat carrier to the PCM module. Guaranteeing for maximum dynamic, the hybrid heat storage concept makes HeatSel ® an ideal component for various applications within the fields of cooling, air Conditioning and heating technology.

HeatStaxx® Air – Energy storage solutions for air-based applications

Designed for air-based applications, HeatStaxx Air is a high performance macro encapsulation made of specially tailored blow molded synthetic material. The macro encapsulation design allows for a combination of a large surface and the smallest possible PCM layer thickness enabling the entire PCM module to run through the phase change process. This leads to high efficient heat transfer (quick charge and discharge) even at very low temperature variations. As the signature shape guarantees a maximum heat transfer coefficient at minimum pressure drop, AirStaxx Air works excellently in air conditioning systems:

  • night cooling
  • solar heating
  • heat recovery ventilation systems
  • easy air conditioning by taking advantage of even smallest temperature variations
  • conveniently stackable and scalable
  • minimum pressure drop, maximum heat transfer
kraftBoxx® – Save PV surpluses efficiently in hybrid storage

The kraftBoxx® is a functional power storage unit, i.e. as a ready-to-connect power-to-heat system solution it stores solar power surpluses in the form of heat for space heating and hot water production. The kraftBoxx uses “heatStixx®”, “heatSel®” or “heatSel® XL” as PCM elements, depending on the storage tank size, and can therefore be used variably, e.g. in detached houses and apartment blocks as well as in office and residential buildings. The advantage of the kraftBoxx® is therefore up to four times the storage capacity and up to 10 times the performance compared to conventional systems – and all this in the same space.

The modular complete system, consisting of a hybrid storage tank, electrothermal station, fresh water station and heating group, enables the entire PV surplus to be used thermally despite fluctuating PV electricity production and varying household electricity requirements thanks to the intelligent control and infinitely variable power modulation. Due to the modularity and scalability of the system, other generators such as heat pumps can also be easily integrated, which means that public and commercial buildings and neighbourhoods can also be operated efficiently.

Above all, however, the imminent expiry of the EEG subsidy after 20 years for the first photovoltaic systems confronts many private households with the problem of the (economically) necessary own power consumption, which can be solved quite easily with the kraftBoxx®, which has just won the smart E Award, and that at a fraction of the cost of comparable battery storage!



Futurium – House of Futures (Berlin)

The sustainable construction and operation of real estate makes a significant contribution to curbing resource consumption and climate change. In turn, energy storage systems are a prerequisite for the increased use of renewable energies and combined heat, power and cooling systems: various applications can be supplied with energy locally and efficiently, for example, by solar systems and heat storage systems. A thermal storage with phase change material can innovatively adapt supply and demand, as one of the best-known projects with an Axiotherm® PCM hybrid storage shows:

In 2019, the “House of Futures”, recently called the “Futurium”, was prominently opened in a prominent location directly on the Spree River in the vicinity of the Federal Ministry of Education and Research (BMBF) and in the immediate vicinity of Berlin’s main railway station. The client is the Bundesanstalt für Immobilienaufgaben (BImA), which is building the house together with the private partner BAM in a public-private partnership (PPP). The “Futurium” is supported by the non-profit supporting organisation “Futurium gGmbH”, in which politics, science and industry are involved. In addition to the Federal Ministry of Education and Research, the founding partners are the Alexander von Humboldt Foundation, the German Academic Exchange Service (DAAD), the German Academy of Sciences Leopoldina, the German Academy of Science and Engineering acatech, the Fraunhofer Society, the Helmholtz Association, the Max Planck Society and the Gottfried Wilhelm Leibniz Science Association. From the business community, the companies BASF, Bayer, Boehringer Ingelheim, Siemens, Infineon and the Deutsche Telekom Foundation have so far participated.

The exhibition and event building is certified in the Gold Standard analogous to the BNB and corresponds to the standard of a plus energy house. The energy concept provides for the primary use of regenerative energy in order to minimize the use of fossil fuels. A central component of the innovative concept is energy storage using a paraffin latent heat storage unit based on HeatSel technology from Axiotherm GmbH (

Depending on cooling requirements for public events PCM hybrid storage was designed as a cold storage. Thermal energy is stored in a hydraulic system that couples different energy converters and consumers. A time-shifted generation of energy and its demand is bridged by by five storage tanks each sized 9,150 l. At the same time, the current output can also be controlled on the primary and secondary sides by means of the variable mass flow: This makes it possible to temporarily draw more power from the storage tank than was fed into it on the primary side.