Once the bodies of water have receded, construction dryers in flood plains spring into action. Not only do they consume a lot of power, they also make a lot of noise. Researchers at the Fraunhofer Institute for Building Physics (IBP) in Stuttgart have now solved both problems. FastDry doesn’t just run silently, so it can work 24/7 in shared apartments and offices, and it’s also extremely modest when it comes to electricity. Plus, success comes faster.
Thermal energy stays in the wall
The drying module consists of a rectangular insulation board laminated on both sides. It is attached directly to the damp wall and heats it with integrated heating wires. The resulting water vapor passes through the permeable materials in the panel and escapes unobstructed through the rear. The thermal energy, in turn, remains in the wall thanks to the insulation. The drying module therefore only needs a small amount of electricity to maintain the temperature and the room is not heated up unnecessarily. For the insulation layer, project manager Andreas Zegowitz, group manager for thermal parameters, climate simulation in the hygrothermal department, and his team use commercially available mineral wool. It is non-combustible and therefore also complies with strict fire safety regulations.
Hot enough but not too hot
The Fraunhofer technology also outperforms infrared heating plates. FastDry uses only about 15 percent of the energy that standard infrared devices use. The working temperature is usually around 55 degrees Celsius. “We chose a temperature that even sensitive building materials can easily withstand,” says Zegowitz. “Hot enough to allow moisture to escape quickly, but not so hot that the user could accidentally burn their hand.
Sensors monitor the drying process
But how does the FastDry module know that the wall is dry? The wall temperature and power consumption of the module are measured continuously. The more moisture the wall has already given off, the less energy is needed to maintain the defined temperature. “If the temperature and energy consumption remain the same over a 24-hour period, the wall can be considered dry,” says Zegowitz. Then it will be turned off automatically.
FastDry is also for historic buildings
The modules can also be used in building shells or in the renovation of historic buildings. “Due to the feared increase in heavy rainfall, the need for efficient drying technology will also increase,” said Professor Hartwig Künzel, head of the hygrothermal department at IBP. “The technology is market-ready and ready for series production.”