The indirect heat metering system is applied to centralized systems where the distribution of the heat transfer fluid is carried out by means of risers: this means that the pipes carrying the heat transfer fluid that passes through the radiators of the individual households, have more points of detachment from the centralized system (the vertical risers) that feed the individual radiators, making it difficult to measure the amount
of fluid that enters each individual apartment.
We use the example where a riser column feeds the radiator of a room and at the same time also that of the room located on the upper floor in a different household.
In this case, since it is impossible to establish the amount of fluid and therefor the amount of thermal energy used by each radiator, the use of instruments defined as heat cost allocator installed on each radiator inside the individual households, avoids the unjust solution whereby heating costs are split according to the millesimal portions corresponding to each property.
Depending on the operating parameters of each radiator, the amount of heat that the radiator releases into the room is indirectly calculated. The sum of the readings of each radiator provides the total consumption data of the individual household then, having set all the instruments installed in the building with homogeneous parameters, the allocation of the total heating costs of the centralized system can be easily attributed to every single household.