Buildings

Buildings

Materials / Chilled Ceilings / Heat Storage

There is a variety of innovative applications for PCMs in the building technology sector. Buildings underlie permanent climatic influences. These range from the change of seasons, night and day temperature variations as well as changes due to heat sources like computer facilities, machines, and humans. A sophisticated building management is required in order to compensate these loads. This is accompanied by a high cost of energy. With the use of PCM the climatisation system can be downsized or even substituted. For example, our CSM board is able to support the climatisation system in the regional court in Düsseldorf, Germany. During the cold seasons server waste heat is stored in the PCMs and can be released later into the building through air channels. This is an example of an active system. Active meaning the climatisation system is at least partially controlling the heat flow from and to the PCM.

A passive system operates through natural climate changes. For example, CSM boards can be installed on suspended ceilings. The sun that shines through the windows heats up the air inside the room. Warm air rises then up to the ceiling on which the CSM boards are installed. Heat is absorbed by the boards in order to melt the PCM. As a consequence, the air is cooled. Cold air sinks down so that the room is cooled. However, one has to consider that for passive systems heat or cold that has been previously absorbed in the room has to be released in order to start anew the following day. This procedure of heat release is well applicable in countries where the nights are considerably colder than the days.

Apart from air-conditioning, the PCM can also support heating techniques. A fruitful combination is a PCM storage device connected to a renewable energy source. For example, the temperature that can be reached by the solar thermal collectors depends on the climate zone and time of year. At a certain level the heat cannot be stored in a water storage anymore due to small temperature differences. However, a PCM is made for the storage of large amounts of energy at small temperatures differences and therefore a perfect addition to this system in the described scenario.

In the building sector, inorganic PCMs are often preferred, e.g. SP21E. Depending on the system and location of the building, melting ranges from approximately 20°C to 30°C (68 F to 86 F) are used. These materials are non-flammable and more economic compared to corresponding organic latent heat materials. However, the number of available inorganic PCM materials for certain melting temperatures is limited.