How does surface cooling work, also for your home? With WEM's clay systems for walls and ceilings, you can not only heat homes, flats and commercial spaces, but also cool them. In summer, simply run cold water through the pipes instead of hot water. This creates a natural air conditioning system that cools gently and pleasantly, without any draughts or noise! Technically, the systems for surface heating and cooling are constructed in the same way; the difference lies solely in the temperature of the heating or cooling water. Therefore, it makes sense to use the same surface for cooling in summer and for heating in winter. A heat pump is required.
Cooling with the WEM climate panel dry construction system The system is suitable for old and new buildings. Installation as a retrofit is also possible. Special panels (Klimaelement MV-D), which are stabilised with a small amount of dispersion, are available for ceiling installation for cooling. In the variety of ceiling cooling systems, the WEM clay ceiling system stands out due to some special properties. It can be installed and connected quickly and cleanly and provides a continuous, even surface. Due to the low installation height with a panel thickness of 2.5 cm (with integrated water-bearing pipes), the system is also well suited for old buildings.
Cooling actually also works via heat radiation, only in a different direction. The excess heat is radiated from the human body towards the cooling surface. From the surface it then flows to the cooling pipes and "heats" the cooling water. This flows back to the heat pump, where the water is cooled down again, i.e. the heat is extracted. It is irrelevant whether the cooling surface is mounted to the wall or ceiling. Nevertheless, the cooling capacity of a ceiling cooling system is greatest because there is also a convective component: Warm room air rises and is cooled on the ceiling. If the cooling surface is also to be used for heating, this can be done without any problems. Since ceiling cooling is usually designed to be rather large due to its relatively low output, very low water temperatures are needed for heating.
Clay has very good sorption behavior and regulates the humidity in rooms. If increased humidity occurs for a short time, e.g. due to cooking or showering, this water vapor is very quickly absorbed by the clay building material. When the humidity drops again, the clay returns the absorbed water to the room. This can result in a moisture content of around 50%, which is optimal for human sensation. For use as a cooling ceiling, this has another special advantage: The performance of cooling ceilings is always limited by reaching the dew point temperature. This means that if the surface in the pipe area becomes too cold, the water vapor contained in the room air condenses and the surface becomes wet. Compared to other systems, e.g. with metallic surfaces, which cannot absorb water at all and immediately start dripping, clay has a strong advantage here. Clay building materials can easily absorb condensation moisture up to certain limits and dry out again without leaving any residue.
The sustainable office building of WEM GmbH, built according to KfW 55 standard, is completely heated with a climate ceiling and very pleasantly cooled in summer. Visitors are welcome to test the indoor climate.
In this hotel, the clay wall (on the left of the picture) is used to cool in the summer and achieve a gentle lowering of temperatures without drafts or noise.
Ceiling cooling in a wooden residential building in northern Italy. The Climate Panels can be quickly installed in dry construction and produce a uniform continuous surface when finished.
Which technology can be used to operate the cooling? In private housing, surface cooling is used almost exclusively in combination with heat pumps. Geothermal probes and groundwater heat pumps are suitable for "passive" cooling. The cooling water is cooled in the ground or groundwater so that no additional energy is required apart from electricity for the circulation pump. Other heat pumps cool "actively": In this case, the refrigerant circuit is reversed and the heat pump works like a refrigerator.
"As we have had outside temperatures of up to 40°C here in Eupen over the past few days, we have been able to see how excellently the wall cooling works. We had 10°C less in the house across the board. That was terrific and is a really good solution."
"...we retrofitted the system in good time in spring with an IGLU box for cooling. This was really great in the hot summer days, the rooms were pleasantly tempered and we could work well without "our heads spinning".