  A new method for accurate indirect heat accounting in apartment buildings has
been recently developed by the Centre Suisse d'Electronique et de
Microtechnique (CSEM). It is based on a data driven approach aimed to the smart
networking of any type of indirect heat allocation devices, which can provide,
for each heat delivery point of an apartment building, measurements or
estimations of the temperature difference between the heat transfer fluid and
the indoor environment. The analysis of the data gathered from the devices
installed on the heating bodies, together with the measurements of the overall
building heat consumption provided by direct heat metering, allows the
evaluation of the characteristic thermal model parameters of heating bodies at
actual installation and working conditions. Thus overcoming the negative impact
on accuracy of conventional indirect heat accounting due to off-design
operation, in which these measurement systems normally operate. The method has
been tested on conventional heat cost allocators (HCA), and on innovative smart
radiator thermostatic valves developed by CSEM. The evaluations were carried
out at the centralized heating system mock-up of the Istituto Nazionale di
Ricerca Metrologica (INRIM), and also in a real building in Neuchatel,
Switzerland. The method has proven to be an effective tool to improve the
accuracy of indirect heat metering systems; compared to conventional HCA
systems, the error on the individual heating bill is reduced by 20% to 50%.
