New software simulates the use of phase change materials in buildings

Ludwigshafen, Germany – May 2008 – Together with Dr. Valentin EnergieSoftware, the Fraunhofer Institute for Solar Energy Systems (ISE), maxit and DAW (Caparol), BASF is making the new simulation software “PCM express” available to architects, planners and house builders. The software makes it possible to calculate the advantages of using phase change materials (PCMs) in buildings. Users can now not only calculate simply and clearly how much more comfort can be gained by using phase change materials, but also the potential energy and cost savings compared with a non-PCM system. The software can currently be requested free of charge via the Internet. The project was supported by the Federal Ministry of Economics and Technology (BMWi).

According to Marco Schmidt of Technical Marketing in the Polymer Dispersions for Construction unit at BASF, there is another advantage for users: “Because the software is an express version, the program can be easily operated by virtually anyone familiar with the structural conditions of a specific building. The simulation software doesn’t only help house builders make decisions, it is also an analytical tool for architects and engineers”, he adds.

The settings make it possible to make calculations for individual rooms or up to ten units of three rooms each. Variables such as construction method, windows, size or local climate are fed into the subsequent dynamic simulation. This means investors, architects and planners can for the first time draw concrete conclusions about the effectiveness and economic feasibility of a PCM solution, which is not possible with a rough estimate.

Projecting the future is always based on assumptions derived from current conditions. All the parameters, such as the rate of price increases, borrowing costs, period under consideration or the useful life of a facility can therefore be freely selected. On the basis of the specified investments, PCM express then dynamically calculates the expected payback period, the rate of return and the capital value of both variants on a comparative basis.

A broad-based portfolio of PCM construction materials is already available today and their impact is now quantifiable for a specific application. “This is another key step towards achieving energy efficient solutions for keeping buildings cool in summer“, says Schmidt. PCM express can be ordered free of charge at www.valentin.de/index_en_page=pcm_express. Information on BASF’s PCMs can be found at www.micronal.de.

How phase change materials work

With Micronal® PCM, BASF has developed a microencapsulated phase change material. Its principle? Microscopically small polymer capsules containing a pure wax storage medium at their core can be inserted into different construction materials such as gypsum wall boards and plasters, aerated cement blocks, chilled ceiling elements, floor screeds, wood-based materials or finishing systems and compounds. If the room temperature reaches the predefined melting temperature (for example, 23 degrees Celsius), the wax inside the microcapsules melts and via this phase change absorbs the excess heat. This stops the room temperature from rising, something no other passive technology can do. If the temperature falls, the wax becomes solid and the capsules release their heat again. The alternating sequence of melting and solidifying is ensured either by nature, for example through temperature differences between night and day, or through the use of activated systems, such as water cooling. In this way, phase change materials help to absorb daytime temperature peaks, thus ensuring more pleasant room temperatures.

As a major supplier to the construction and coatings industry, BASF, through its Acrylics & Dispersions division, develops, produces and markets polymer dispersions, powders and solutions based on acrylates, styrene and butadiene worldwide. They are used, for example, to manufacture plasters, finishing systems and compounds, roof coatings and ceramic tile adhesives. They act as binding agents in paints and coatings. Further information is available online at www.basf.de/dispersions.