Indirect metering is used in buildings with a “vertical distribution” centralized system.
Indirect heat metering, on the other hand, involves the use of devices or other h.c.a. installed, together with the thermostatic valve or other thermostatic actuator, on all heating elements (radiators, thermocouples, etc.) of a heating plant of each property unit, thus allowing to set, in each room, the desired temperature. These devices allow an estimate of the thermal energy released in the room by the single terminal whose sum will give the estimate of the heat provided throughout the apartment. To achieve energy savings, heat smart metering and thermoregulation of the energy delivery of the individual terminals are required.
Currently the laws in force in the field of new heating systems require the adoption of thermostatic valves that must have at least two levels of temperatures (one for day comfort and one for night use).