Absorptive common-mode filter for transmission lines

Heaters can be controlled via thermostats to set the desired room temperature. With manual thermostats, influencing factors such as day time, heating season, presence of people and open or closed windows cannot be detected. Manual adjustment depends on the situation, e.g. during prolonged ventilation or when persons leave the room. Systems for central control and saving of heating energy are known, but they are not always advantageous in situations when individual rooms are used differently. Electronically controlled valve heads enable time control. Some systems can detect and react to abrupt temperature changes (e.g. when windows are opened). Networked systems can be linked to sensors (e.g. window contacts and presence detectors) and allow remote control. However, they must already be integrated in the construction phase of the building. Retrofittable solutions are available for private living spaces that are battery-operated and connected via wireless technology. System-related power consumption, maintenance effort and design of the radio infrastructure can be limitations for the latter systems.