Heat consumption accounting

Heat and cooling accounting

With the implementation of regulations for the accounting of heating and domestic hot water consumption (UNI-10200), many residential buildings have equipped themselves with tele-reading systems through the installation of heat allocators and electronic meters for cold and hot water. Consumption is monitored depending on the equipment installed in the building:
  • Via radio from the landing (walk-by floor) or USB key (connected to the concentrator in the central heating room);
  • Remotely via telematics (tele-reading), using MS-BUS concentrators with GSM, GRPS, and WEB transmission;
  • Via the web portal of the brand of the installed system.
The use of such systems allows for the reading of meters and allocators without physically entering the property. Depending on the installed systems:
  • It will be sufficient to stay in the common areas of the building to collect readings from all residents, either by radio (walk-by floor) or USB key, if a concentrator is installed that only allows local data extraction (e.g., in the central heating room);
  • Read the consumption remotely via telematics, for example, through a SIM card installed in the building’s data collection unit (GSM transmission);
  • Connect to the web portal of the installing company or supplier (e.g., ISTA, B-METER) using login credentials (username and password) to access data made available by the server.

The most common systems in residential buildings in Bologna and surrounding area include:

  • Save Energy
  • Sontex
  • Caleffi
  • Siemens
  • Baxi 

ELCA regularly performs meter readings using these and other systems. Additionally, the company notifies the building management of any anomalies recorded by the heat meters and allocators.


Tele-reading and radio-reading services with systems:

  • Sontex
  • Save - Energy
  • Siemens
  • Honeywell
  • Qundis
  • Caleffi
  • Perry
  • Ista
  • Other brands

EU Directive 2012/27/UE

The directive establishes a common framework of measures to promote energy efficiency in the European Union. Its goal is to achieve a 20% reduction in energy consumption by 2020 and to lay the foundation for further improvements in energy efficiency.

In Article 9, the directive addresses existing buildings:
"[...] In multi-occupancy buildings and buildings with mixed uses supplied by a central heating/cooling source or district heating networks, or by a central source supplying multiple buildings, individual meters must be installed by 31 December 2016 to measure the consumption of heat, cooling, or hot water for each unit, if technically feasible and cost-efficient.

Where the use of individual meters is not technically feasible or cost-effective, individual heat allocators must be used to measure heat consumption at each radiator."
The full directive is available for download from our website under the "Legislation and Regulations" section.

Heat accounting

Heat accounting is an effective system that allows each individual resident to fully manage their central heating system, paying only for the energy they consume. Residents can turn their radiators on and off or adjust the temperature according to their needs. With the installation of thermostatic valves and electronic heat allocators, the following objectives can be achieved:
  • Increased living comfort;
  • Improved energy efficiency of the entire building;
  • Savings on heating costs (the more residents adopt energy-saving behaviours, the more they will save);
  • No need for new installations or building work;
  • Guarantee and security of the central heating system;
  • Lower fuel consumption (savings of between 10% and 30% annually);
  • Greater environmental responsibility;
  • Differentiated temperature control for each room;
  • Independence in managing the system, with the ability to choose heating schedules.

The heat allocator

The installation of heat meters on individual radiators is known as "allocation". Each heat allocator is calibrated and configured at the time of installation. The device measures the energy supplied to or emitted by the heating element.
The heat allocator is installed on the radiator in such a way that it cannot be removed without breaking a tamper-proof seal, and it calculates the so-called "thermal units" using specific sensors and based on certain parameters. These devices are not simple "calorimeters" but true indicators of energy consumption. The device is powered by a long-lasting battery (approximately 10 years).

The allocators can be connected via radio waves to central collection units, offering the following advantages:
  • No need to install cables or other electrical works;
  • Continuous monitoring of each allocator to prevent malfunctions, tampering, and alterations;
  • Ongoing verification of proper functioning and battery status;
  • Easy installation, management, and monitoring;
  • "Remote" reading of consumption even when no one is present in the apartment;
  • Control of local temperatures, room by room.
  • The installation of this type of system, combined with the energy-efficient behaviour adopted by each user, will result in significant energy savings.

The thermostatic valve

The installation of the heat allocator allows for precise consumption measurement, but to manage it effectively, a thermostatic valve must also be installed. The thermostatic valve is a device that allows users to set the desired temperature in each room, and once the temperature is reached, it maintains it consistently.

Its operation relies on the opening/closing of a valve to allow or block the flow of hot water into the radiator automatically, thanks to the thermal sensor it contains, which detects the temperature in the room. The installation of the thermostatic valve is carried out without any structural work or changes to the existing system.

The allocation of heating and hot water costs – UNI 10200 standards

The standard establishes the criteria for dividing the total costs of heating and hot water and applies to condominium-type buildings with central heating systems.
The core principle of UNI 10200 is as follows: each user pays according to their actual consumption, thus rewarding the responsible behaviour of the user.

Total energy consumption is divided based on the following standards:
  • Voluntary consumption (variable share): These are the consumptions due to the voluntary actions of the user; for example, if the user feels cold, they raise the thermostat setting and consume more, and if they feel hot, they lower the temperature in the house and consume less.
  • Involuntary consumption (fixed share): These are the consumptions independent of the user's actions; mainly, these are heat losses from the distribution network and should be allocated according to the heating shares (millesimi).
A heat regulation and metering system requires:
  • Devices suitable for measuring heat (meters, allocators, and other systems);
  • A design (mandatory according to Law no. 10/1991), installation (by qualified professionals), and testing;
  • A distribution criterion, i.e., what is established by UNI 10200;
  • System management (device readings and related consumption, cost allocation).
The procedure for dividing the total cost can be summarised as follows:
  • Determine the total cost;
  • Determine the energy consumed;
  • Calculate the unit cost of useful energy (the cost of energy leaving the generator). If the generator is also used for producing hot water, it is necessary to determine how much energy from the generator has been used for this purpose. For this reason, it is advisable to install separate meters for heating energy consumption and hot water consumption;
  • Allocate the total useful energy between voluntary and involuntary consumption;
  • Allocate the voluntary useful energy based on the readings of the devices;
  • Allocate the involuntary useful energy based on the heating shares (millesimi).

Conclusions

The installation of a metering system should not only be seen as a legislative obligation but also, and above all, as an opportunity for savings and cost restructuring. The combination of a centralised system, which allows the distribution of maintenance and management costs among all the residents, with a heat metering system that rewards the more responsible households, enables significant savings. Thanks to the experience gained, ELCA is able to support both administrators and residents in their decisions and in managing the system of readings, calculations, and consumption allocation.
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