The performance of digital signals depends to a great extent on the frequency. At least one collector hose for the circulating heat transport medium is provided in recesses in the concrete such that the cross section of the collector hose is located entirely within an outer outline of the cofferdam, whereby heat from surrounding water is absorbed by the collector hose and used for heating of the space. In some embodiments, the method includes providing a poppet body for a valve, providing a magnet, and providing a mounting member configured to attach the magnet to the poppet body. The composition possesses excellent handleability and workability at low viscosity and which, after application onto surfaces, is not subject to slipping-off when this surface assumes a vertically position, even under harsh temperature conditions.