Gerhard ZWEIFEL HSLU / Switzerland gerhard.zweifel@hslu.ch Ventilation for buildings - Calculation of room temperatures and of load and energy for buildings with room conditioning systems EN 15243 Gerhard ZWEIFEL HSLU / Switzerland gerhard.zweifel@hslu.ch

Outline The EU CENSE project Scope of the Standard Calculation method-classes General calculation scheme HVAC systems overview Important technical features Verification Informative annexes This is the outline of the presentation, which also includes a short description of the CENSE project

The EU CENSE project (Oct. 2007 - March 2010) Aim of the project: To accelerate adoption and improved effectiveness of the EPBD related CEN- standards in the EU Member States These standards were successively published in the years 2007-2008 and are being implemented or planned to be implemented in many EU Member States. However, the full implementation is not a trivial task Main project activities: To widely communicate role, status and content of these standards; to provide guidance on the implementation To collect comments and good practice examples from Member States aiming to remove obstacles To prepare recommendations to CEN for a “second generation” of standards on the integrated energy performance of buildings The CENSE project is active since 2007. All activities are related to the EPBD-related CEN-standards, where EN15243 is one of them

Brief introduction A brief introduction to the CENSE project and the CEN-EPBD standards is provided in a separate presentation: Several documents are available from this project

More information More information and downloads: www.iee-cense.eu Disclaimer: CENSE has received funding from the Community’s Intelligent Energy Europe programme under the contract EIE/07/069/SI2.466698. The content of this presentation reflects the authors view. The author(s) and the European Commission are not liable for any use that may be made of the information contained therein. Moreover, because this is an interim result of the project: any conclusions are only preliminary and may change in the course of the project based on further feedback from the contributors, additional collected information and/or increased insight. Which you can easily access at the CENSE home page

Scope of the standard Covers system related aspects for buildings heating, cooling, humidification and/or dehumidification needs For the ventilation reference to EN 15241and EN 15242 Based on results from EN ISO 13790 calculations of building energy demand For temperature and load calculation reference to EN ISO 13790 and EN 15255 Key issue: possible to use any calculation method especially including hourly simulations as long as general requirements are fulfilled Main driving force: variety of systems in the HVAC domain is very large no general method is able to cover all types of systems The standard has a quite large scope including non EPBD related design issues. It adresses buildings which need not only heating, but also cooling and/or humidification/dehumidification. It cevers all system related aspects of these buildings, but references other standards where appropriate. It does not impose a specific calculation method. It also includes the latent load and energy calculation, since this is nowhere else covered.

Calculation method - classes Type BhSh Possible to take into account hourly interactions between building behavior and system behavior Example: VAV system Type BmSh When system behavior is not dependent on building behavior System behavior calculated on hourly values before building calculations Type BmSm and BhSm System behavior calculated by averaged monthly, seasonal or annual values Using statistical analysis based on hourly calculation for typical climates, configurations etc. Commonly used category: based on the frequency distribution of hourly outdoor air temperature and/or humidity Combined with hourly or monthly / seasonal building calculations BhSh or BmSh SYSTEM LAT CALCU­ ION Hourly Monthly seasonal annual BUILDING BhSh BhSm CALCULATION Monthly seasonal BmSh BmSm Several categories of calculation methods for buildings and systems and their combinations are defined

General calculation scheme In a general calculation scheme, the basic requirements for the calculation, i.e. the processes which it has to cover, are illustrated: losses and auxiliary energy needs at different stages.

HVAC system overview CODE SYSTEM NAME DOES NOT ALWAYS INCLUDE HEATING PROVISION AND MAY BE USED WITH SEPARATE HEATING SYSTEM (INCLUDING ROOM HEATERS WHICH MAY BE WITHIN TERMINALS) DOES NOT INCLUDE INTEGRAL PROVISION OF VENTILATION AND MAY BE USED WITH SEPARATE (COOLED) VENTILATION SYSTEM A All-air systems A1 Single duct system (including multi-zone) A2 Dual duct system A3 Single duct, Terminal reheat A4 Constant Volume (with separate heating)  A5 Variable Air Volume (with separate heating) B Water-based systems B1 Fan coil system, 2-pipe B2 Fan coil system, 3-pipe B3 Fan coil system, 4-pipe B4 Etc…. Since system calculations depend on the system types and the variety of the systems is large, an overview of systems is given. The table in the standard is much longer, only a part is shown here.

Important technical features The important technical features influencing the energy conspumtion of systems are related to the system types. Only a part of the very extensive table in the standard is shown here. This is used to check if a calculation method covers all the required features of a system type (see verification step 1 below)

Verification Key requirements Two step verification approach proposed Credibility: mechanisms technically sound and results plausible Discrimination: rating should be better for systems and buildings clearly more energy-efficient. Repeatability: Different users should get essentially the same results for the same building Transparency: Straightforward to check data used and execution of the procedure Two step verification approach proposed The standard gives general requirements on a verification process for calculation methods.

Verification steps Step 1: Define required characteristics check that the method appears to provide them Step 2: Verification of calculation accuracy Reference to several techniques for verifying calculation methods (table) Application decided on a national basis If verification technique used -> results obtained to be stated HVAC system area: only few validation tests from research projects are ready to use for application in standards available still a lot more research needed Two main steps for a verification are proposed. Step 1 is a check whether all elevant aspects of a system are covered in a calculation method. Step 2 adresses the calculation accuracy, but there is still lack of available validation tests.

Informative annexes Reference to the Energy Diagnosis Reference (EDR) Dutch methodology to verify performance of calculation procedures still under development systematic approach to verification of calculation methods referring to different validation tools and standards Example methods given for many specific aspects Impossible at this time to define single common method due to the variety of approaches in use in the different countries Often building regulations refer to National standards, impossible for those countries to change One or two more generations of standard revisions needed to get to a closer harmonization. This standard is the first step in this direction. There is a large number of mostly informative annexes in the standard. For the calculation of specific system parts like losses and auxiliary energy demand of chilled water distribution and generation, emission losses, auxiliary demand for heat rejection systems etc. example methods from national standards are given.

More information More information and downloads: www.iee-cense.eu Disclaimer: CENSE has received funding from the Community’s Intelligent Energy Europe programme under the contract EIE/07/069/SI2.466698. The content of this presentation reflects the authors view. The author(s) and the European Commission are not liable for any use that may be made of the information contained therein. Moreover, because this is an interim result of the project: any conclusions are only preliminary and may change in the course of the project based on further feedback from the contributors, additional collected information and/or increased insight.