After a process of almost 2 years, the last (provisional) meeting of the standardization working group of the Belgian Annex on the standard for determining the thermal load for rooms (EN 12831-1) will take place on 10th of December. After this meeting, the text of the Belgian standard will be final and the standard will be submitted for official publication. Below you will find an overview of the final points of discussion.


A brief look back

In January 2018, a working group was set up to draw up a Belgian Annex as an alternative to the suggested overly complex methodologies proposed in the European standard. On the basis of a submitted proposal, a text proposal was discussed in a number of working group meetings. At the end of 2018, a consensus was reached to submit the draft for public consultation. The comments from this public consultation were discussed during a working group meeting on the 3rd October 2019. A number of final points of work emerged from this consultation, based on which a new proposal has been drawn up and will be discussed in the Belgian Mirror Committee SA/E228 on 10 December. Afterwards, the standard will be submitted for official publication of the Annex in the Belgian Official Gazette, which will finalise the Annex.

For more information on the standardization process for the EPBD standards, click here.

What is the thermal load standard for rooms (EN 12831-1)?

The EN 12831-1 provides options for calculating of heat loads of spaces (also known as the heat loss calculation). This calculation is used by installers to determine the size of heating and cooling installations. This is based on the calculation of the maximum heat output required per hour for a heat generator to reach or maintain an internal design temperature at a certain outside air temperature. Within EPB, the standard is part of a validated supporting document in Flanders, which can demonstrate that a designed delivery system is capable of achieving a certain level of comfort. Alternatives are the use of values of absence or other documentation, but this is not always sufficient to meet the requirements.

For more information about the heat load standard for spaces, click here.

Important discussion points for the Belgian Annex

The final discussion points for this standard focus on the values for airtightness and infiltration flows. Both have an impact on the risk of over-dimensioning; this was an important point of discussion throughout the process. Over-dimensioning can be caused, among other things, by the use of parameters or default values that are ‘too safe’. The values for airtightness are expected to further reduce in the coming years through innovations in building technology. In regard of the values for infiltration flows the discussions focus on the range of options available; The standard must offer a guidance to the installer for selecting the right value, but at the same time should not be too rigid. At the last meeting on the 3rd of October it was decided to take some additional time to formulate a final proposal on these two points. These will be discussed on the 10th of December.

For more information on the discussion points concerning the heat load standard, click here.

Update of the Belgian Annex to the thermal load standard for domestic hot water (EN 12831-3)

At the same time as the working group for the Belgian Annex for the calculation of the heat load of spaces, a working group for the Belgian Annex for calculating the heat demand for domestic hot water (EN 12831-3) was launched. The working group has been put temporarily on hold pending a first text proposal for the Belgian Annex. As soon as a text proposal is available, a next meeting will be scheduled.

EN 12831-1 and EN 12831-3: Role of workgroup within the standardisation landscape

The standards EN 12831-1 and EN 12831-3 are part of the portfolio of standards managed by the European Committee for Standardisation CEN/TC228. This commission is focused on the development and maintenance of standards for heating systems and water based cooling systems. Currently the committee manages around 30 (EPBD) standards, of which the majority was approved in 2017. The Belgian Mirror Committee SA/E228 is the Belgian representation of the CEN committee. Sirris-Agoria is its sector operator. The activities of the Mirror Committee consist of voting, commenting and revising the proposals for (European) standards. In addition the Mirror Committee has the possibility to develop a Belgian standard or Annex to for example define local parameters. The two working groups that are currently active within the Belgian Mirror Committee are aimed at the development of Annexes for the European '12831' standards. The standards describe the calculation methodology to determine the heat load of buildings for spaces (EN 12831-1) and domestic hot water (EN 12831-3).

Would you like more information about the standards or annexes? Members of Agoria may become join the mirror committee SA/E228 as experts. Contact Ludo Vanroy for more information.