Phase change materials (PCMs) are only used sporadically in construction, although various products and systems have been available on the market for several years now. The PCM Demo II research project therefore intends to test and scientifically evaluate the practicality of PCMs in buildings. A sub-project is focussing on PCMs in heat storage systems. For this purpose, such systems are being incorporated in commonly used buildings and their performance investigated.
The application of phase change materials (PCM) in buildings has been studied for several years. They can help improve indoor comfort and the efficiency of ventilation, air conditioning and heating systems. In a first fundamental project from 2006 to 2009, different applications were tested and evaluated in a broadly based EnOB research project. Since then, various products and systems with PCM have become available in the construction industry but they are used only sporadically.
With this research project, the practicality of the available products and systems is now to be tested and scientifically evaluated. The systems are built into normally used buildings and their performance is evaluated. Several research institutes are co-operating with medium-sized enterprises with the aim of promoting the use of innovative materials and building components in the construction and renovation sectors.
This involves the following systems:
- PCM in surface cooling systems for non-residential buildings
- PCM in ventilation systems for non-residential buildings
- PCM for heat storage systems for heating and domestic hot water
The following deals with this sub-project for PCM in heat storage systems. The aim of this project is to establish long-term monitoring for PCM heat storage systems for heating domestic hot water in a number of reference objects in order to evaluate scientifically significant measurement data. This would bring about the conditions required to objectively evaluate the systems and provide suitable application scenarios.
The focus of the project is on the investigation of PCM heat storage systems for energy-efficient space heating and the preparation of domestic hot water. The PCM storage systems are installed in actually used buildings and measured as part of an extensive monitoring process.
A modular heat storage system with salt hydrate as a PCM is being examined — it can store thermal energy for several days and weeks. In addition, a floor slab made of concrete with micro-encapsulated paraffin for residential buildings is being examined, which serves as a low-temperature heat reservoir for a residential building in combination with heat pump technology.
The storage systems will be monitored for a longer period once the measurement equipment has been set up.
For several years now, various products and systems have been available on the market, including the following systems examined in the research project:
- Modular PCM heat storage system: the heat storage system is being developed under the brand name of Thermobatterie and can be integrated into heating and hot water preparation like an ordinary storage system.
In addition, there is a novel system under development in the project:
- PCM heat storage plate of made of concrete: the in-floor PCM thermal storage slab is an element of the Energy Efficiency House Plus concept of Institut für Umweltenergie (IfU). Micro-encapsulated paraffin is added to the concrete to raise its thermal storage capacity.