Centralized heating: installation and consumption individualization systems

Since the entry into force in 1999 of the Regulation of Thermal Installations in Buildings (RITE), the installation of each user in a building of new construction with system centralized heating must have a counter, that allows you to distribute the costs according to your consumption.

In regards to the existing buildings at that time and that they had central heating, the Directive 2012/27 / EU imposed obligations related to the individual accounting of energy consumption, including that relating to thermal energy from centralized heating systems.

With this directive, recently modified, it is intended that the consumer have the right to know your spending periodically, to be able to adapt the use it makes of energy and pay part of the cost of heating the building, based on your individual energy demand. This directive has recently been transposed into the Spanish legal system through the Royal Decree 736/2020, of August 4, which regulates the accounting of individual consumption in thermal installations of buildings. This regulation establishes that every existing building with a centralized thermal installation (heating or air conditioning) that caters to multiple users:

You must have a system that allows measure or estimate the energy consumption of each user.

End users must have the means necessary to control their own consumption.

The reading and invoicing or distribution of costs of the expenses to each user must be carried out respecting certain requirements (remote reading, information on invoices, among others).

The owners of the facilities are responsible for carrying out these adaptations in certain deadlines and in accordance with the established procedure.

Systems to measure or estimate the individual consumption of each user

What is the best system to measure and distribute heating costs for each user?

Depending on the centralized heating system that our building has, we can choose between installing a individual energy meter in each dwelling or energy cost allocator. It is necessary to indicate that these possible actions on the heating installations to provide them with systems that allow the distribution of costs among their users, do not act directly on it or improve its energy efficiency, but they do modify the pattern of use by users. the users.

In other words, they are measures that promote energy savings:

Individual energy meter cost allocators

La perfect solution to measure and distribute expenses consists of providing each user with a energy meter, because it is the device that account exactly (with a precise margin of error) the energy consumed by each user, so that this data is used directly in billing or cost sharing.

Some buildings have, however, a distribution of heating water by columns (vertical) and in them an individual energy meter it is not viable.

In these cases, the most suitable solution is to use cost allocators mounted on radiators. These devices, which do not modify the operation of the heating installation and do not require works for their assembly, estimate the energy that yields each radiator so that, since all users have the same estimation system, part of the costs of the heating service can be distributed proportionally between each one of them.

The first principle to achieve a rational use of energy, like any other product, is that each user assumes the cost of its use.

In this way, when a thermal installation is equipped with individual meters or cost allocators, which allow part of the costs of its use to be distributed according to the cost recorded by each user, it is offering the right to pay based on the use that is made from the installation.

Therefore, those users who spend less energy on heating, both for their activity regime (closing of radiators in rooms without use or prolonged absences), due to the Characteristics of your home or premises (intermediate floors facing south) or by the improvements that have been introduced (ex: well insulated windows), they will pay less.

According to the estimates offered by the Institute for Energy Diversification and Saving (IDAE), as well as the experience in this regard in European countries where its use has been widespread for more than forty years, ultimate energy saving for all the users of the installation with the individual distribution of expenses, It is usually higher than 30%.

In the territorial scope of the Community of Madrid, there is a study by the University of Alcalá de Henares, from December 2016, which quantifies this saving above 25%.

Means to control own consumption: thermostatic valves

Most of the centralized heating installations of buildings prior to 1984 they lack devices that allow users to regulate the temperature inside homes or premises. For this reason, the only alternative, in case you want to interrupt the service in a dwelling or in a specific room, is to manually act on the keys of each radiator which, in many cases, no longer work properly due to their age.

That is the reason why, frequently, it is observed that in buildings equipped with these heating systems, some users are forced to open the windows, with the consequent waste of energy, to regulate the interior temperature.

Installation of thermostatic valves

To solve this problem, it is possible to equip the installations with devices which open or close the way from hot water to the radiators, depending on whether the temperature that the user wishes inside the room has been reached:

Action on centralized heating installations to provide them with thermostatic valves with thermostatic head (thermostatic valves), modifies the operation of the installation and improves its energy efficiency. In addition, it improves the comfort of users since they can choose the temperature in each room.
For its correct operation, it is required that the hydraulic distribution system of the entire installation has been adapted so that it is capable of working well at variable flows, which results in a better operation of the installation and an improvement in comfort. It is a measure that encourages energy savings as well as the energy efficiency of the installation.
The use of thermostatic valves directly affects on the demand for heating, since the valve closes or opens the passage of hot water to the radiator depending on whether the desired temperature in the room is reached or lost. In this way, the rooms are not heated beyond what is desired, without the user having to turn the radiator stopcock to open or close each time they want to do so.

In addition, by adapting the hydraulic circuit to variable flow operation and rebalancing it, typical operating problems of these installations will be corrected, such as; that in certain heights, low or attics, the hot water does not arrive with sufficient temperature or arrives too hot, as well as that certain columns do not reach the desired temperature.
To achieve this, the hydraulic circuit will be equipped with devices such as variable displacement electronic pumps and high efficiency or differential pressure balancing valves,
Additionally, combined with the use of condensing boilers, it further improves the performance of the installation, since it allows the boiler runs with less load and thereby increase its performance.

Therefore, this measure leads to an improvement in the operation of the whole installation already a overall cost reduction, because each user will be able to save more, depending on their comfort needs, since the radiators will remain open, only for the necessary time.

As a complement to the above, it is also an opportunity to take advantage of technological evolution and opt for electronic heads to act on the thermostatic valves. With these relatively low-cost devices, the operation of home heating can be managed with little effort.

Thus, it is possible schedule schedules on each radiator, so that a room can be heated, for example, in the evening. All this, without having to close the radiator manually and without having to dispense with heating in the rest of the house.

In any case, it must be remembered that the buildings with centralized heating installations were conceived for a joint operation of these facilities so that, in general, a complete individualization of the operation for each user will not be possible.

For this reason, it will be necessary to continue guaranteeing minimal power demand in each home or premises, a minimum circulating flow for the proper functioning of the boilers, as well as the scheduling, to avoid inefficient operation and distribution losses during times of low or no demand.

Readings and billing

With regard to meter reading and individual billing for this type of centralized facility, there are certain common expenses that do not depend on the use that each individual makes. In this sense, the owners of the installations usually establish a system double cost sharingIn which certain percentage is intended to cover those that do not depend on individual use (between 25 and 40%) and the rest is distributed proportionally to the consumption recorded by the metering systems of each user (between 60 and 75%).

There are different models for reading management, cost sharing and billing of heating installations, so that in each building, you can choose for the one that best suits your needs, uniquely defining issues such as:

Purchase or rental of metering equipment
The purchase or rental of the reading taking system,
Taking readings with own or subcontracted means,
The frequency of readings (daily, weekly, monthly, bimonthly, one per season, etc.),
The billing frequency (monthly, bimonthly, fixed fee with regularization according to annual reading, etc.),
Billing with own or subcontracted means.

Obligations of the neighboring communities

La regulations in this regard has established the following meter reading guidelines, información to the consumer and distribution of costs, which must be respected both for the buildings in which new reading and billing systems are installed, and in those that already had them installed, adapting in this case to the new established requirements:

remote reading service

All consumption accounting systems that are installed must have a remote reading service and those that already exist must have it before the 1 of January of 2027.

The installer, or, where appropriate, the company in charge of the measurement, distribution and accounting service, must inform, prior to signing the contract, if the technologies used allow the possibility of a change in the provider without the need to incur additional costs.

Reading of metering equipment

The information on the reading of the metering equipment and the individual liquidation, is provide free of charge to the final consumer, at least once Every two months. If the reading is done remotely, the settlement will be made monthly.

The costs derived from the attribution of this task to a third party, may be passed on to end usersprovided that such costs are reasonable and affordable.

Information on energy costs in each bill

It will be guaranteed that with the individual liquidation, it will be provided free of charge information appropriate for consumers to receive a complete list of your energy costs, with at least the minimum content that is included in the Annex IV of Royal Decree 736/2020, of August 4.

Among others, it must include information on:

that current real prices.
el actual energy consumption or the total cost of heating.
the readings of the heating cost allocators.
that claim procedures.
the user power consumption comparisons final: between the current consumption and its consumption of the same period of the previous year, preferably in graphical form.

Percentages of fixed and variable costs

In buildings where a individualized accounting system, the consumption data will serve to determine the variable cost per consumption corresponding to each user, and will be completed with a fixed cost derived from maintenance and heat lost in distribution or used to heat common areas.

The determination of the weight that the fixed and variable costs must have in the individual settlements must be established by the owners of the facilities. The variable cost should be between 60% and 75% of the total cost, taking into consideration the technical criteria of the maintainer of the thermal installation.

In the event that any of the owners of the heating or cooling installations had not installed an individual accounting system, it will be applicable, at least, the highest ratio of consumption per square meter of surface, of those calculated in the process of preparing the individual settlements.

Deadlines and communications to the administration

Term to execute the investment

The term to execute the investment is established according to the climatic zone in winter, which in turn depends on the altitude of the municipality, as indicated below:

El 1 May of 2022, for buildings of non-residential use and for buildings with 20 or more dwellings in climate zone E (site height above sea level greater than 1000 m), . Examples of municipalities in zone E: Cercedilla, Los Molinos, Miraflores, Navacerrada, Pinilla del Valle, Rascafría,….
El 1th October 2022, for buildings with less than 20 dwellings in climate zone E and for buildings with 20 or more dwellings in climate zone D (height of the site above sea level between 500 and 1000 m). Examples of municipalities in zone D: Alcalá de Henares, Collado Villalba, Colmenar Viejo, Madrid, Móstoles, San Sebastián de los Reyes, Torrejón de Ardoz,….
El March 1th 2023, for buildings with less than 20 dwellings in climate zone D, and , for buildings with 20 or more dwellings in climate zone C (site height above sea level less than 500 m). Examples of municipalities in zone C: Aranjuez.
El May 1th 2023, for buildings with less than 20 dwellings in climate zone C,

You can check the height above sea level of a specific municipality in the following link.

Reference rules

Reference rules

Royal Decree 736 / 2020, of August 4, which regulates the accounting of individual consumption in thermal installations of buildings.
Directive 2012/27/EU of the European Parliament and of the Council, of October 25, 2012, on energy efficiency, amending Directives 2009/125/EC and 2010/30/EU, and repealing Directives 2004/8/EC and 2006/32 /EC.
Directive 2018/2002 of the European Parliament and of the Council, of December 11, 2018, which modifies Directive 2012/27/EU on energy efficiency.
Royal Decree 1027 / 2007, of July 20, which approves the Regulation of Thermal Installations in Buildings.

Centralized heating: systems for individualization of facilities and consumption