Calculation methods and software 171

Task: Provide recommendations for best calculation methods and software used by the EU Member

States

Due to the fact that ISO 13790 was approved in 2008, and a number of the supporting standards were approved later, several of the EU Member States are in the process of updating their calculation methodology and supporting national standards/input values to comply with the ISO 13790 and supporting standards in force. Some few countries have updated their calculation methodology, some are in the process of updating, and several have not started yet.

Regarding software/calculation tools, in principle there are three different types available:

1. Detailed, dynamic tools both for systems design/modelling and energy performance calculations

2. More simplified tools only for energy performance calculations (energy auditing, documentation of compliance with minimum energy performance requirements, energy need and use for energy certification)

3. Energy performance certification tools (used to generate Certificates and information to national Inventory)

Regarding the Certification tool, this could either include the energy performance calculation algorithms as needed for type 2 in the tool itself, or it could be based on energy input as calculated by a separate tool.

For the purpose as defined by this Study, the calculation methodology recommended in chapter 6.5 is covering type 2 above, and type 3 if the energy calculation algorithms are included in the Certification tool.

In table 7.2-1, a brief description of the calculation methodology and related software is provided for the Netherlands, United Kingdom, Denmark, Germany and Bulgaria.

172 Table 7.2-1 National calculation methodologies and software in some European countries

Country Software Comments

Netherlands NPR Software http://www.nen.nl/web/No rmshop/Norm/NPR- 5129A22010v.2.2-nl.htm http://www.nen.nl/web/No rmshop/Norm/NPR- 2917A22010-v.2.2-nl.htm

There are two official energy performance assessment software products in Netherlands:

1. NPR 5129 + A2: 2010 v2.2 – Calculation program (EPW), Energy performance of residential buildings and residential functions. This is the latest version of the existing software following the Dutch National Standard NEN 5128 Energy Performance of residential buildings. 2. NPR 2917 + A2: 2010 v2.2 - Calculation programme (EPU), Energy performance of non-residential buildings is the latest version of the existing software following the Dutch National Standard NEN 2916 Energy Performance of non -residential buildings.

The new NEN 7120:2011 – Energy Performance of Buildings (www.nen.nl/NEN7120) contains new energy performance assessment methods for residential and commercial buildings, both new and existing buildings, and will require new software.

It has been decided that the new software tools are to be developed by the commercial sector.

Since the latest calculation methodology is from 2011, it would be of relevance for the Contracting Parties to study the new calculation methodology developed in the Netherlands.

Since they have decided to develop new software, it is assumed that the existing software cannot be considered a useful basis for developing new software for the Contracting parties.

United Kingdom

UK and Ireland – Simplified Building Energy Model (SBEM with iSBEM interface)

This software is designed for different types of buildings, other than dwellings.

The latest version is based on monthly calculation method adjusted to BS EN ISO 13790:2008 – Energy Performance of Buildings – Calculation of Energy Use for Space Heating and Cooling.

Some specific features:

- Includes new calculation methodologies for lighting and auxiliary energy from 2010

- Has a substantial database for construction and glazing, activities for different zones, HVAC systems and lighting - Includes CO2 emission factors

173 - Generates Energy Performance Certificate

For dwellings, software requirements are defined in the document SAP. Based on this, different companies have developed their own software which are offered in the market (the list of software products, officially tested and accepted for use are made public with the indication of the company names, contact data and the names of the software).

The iSBEM software is owned by the UK Government who can licence it without charge to other governments for Regulatory purposes, but it needs to be modified to meet the needs in other countries.

Denmark National calculation tool Be10

http://en.sbi.dk/publication s/programs_models/bsim

Be10 is the official Danish software for checking compliance with the Building Energy Regulations 2010 (BR10).

The calculation methodology seems to be using the monthly method.

The program calculates the energy performance requirements following EN ISO 13790 and reference standards and displays whether such requirements are met.

Calculates the expected energy use for heating, ventilation, cooling, hot water and artificial lighting dependent on e.g. building design, building envelope, daylight access, ventilation system, heating installation and energy supply including alternatives as solar heating, PV and wind power and heat pumps in all types of buildings e.g. houses, block of flats, offices, institutions, schools, shops and workshops.

Be10 uses built-in Danish climate file, but other climate files can be made and used.

Since the latest calculation methodology is from 2010, it would be of relevance for the Contracting Parties to study the new calculation methodology developed in Denmark. It should also be investigated whether the software is flexible enough and available to be adjusted as basis for developing new software for the Contracting parties.

174 Germany IBP 18599 Version 4 -

Software package http://www.heilmannsoftw are.de/ibp/produkte

Energy performance rating software for implementation of the calculation methodology of DIN V 18599 for residential and non-residential buildings, including profitability calculations, PV simulation according EN 15316-4-6, etc. The calculation methodology is fully described in 11 parts, in total more than 800 pages. The German calculation methodology is based on a large number of pre calculated variants and tabulated data for a common climatic zone represented by reference location (city of Würzburg). Options:

IBP: 18599 Standard (IPB-02) - for energy rating according DIN V 18599 of small and medium-sized projects including residential buildings, mixed-use buildings, and single use buildings such as schools, supermarkets compact administrative buildings, etc. are calculated. The version is limited up to 1 000 m2 foot print area and max. 5 calculation zones.

IBP: 18599 High End (IPB-01) - for energy rating (calculations) for medium and large projects with unlimited number of zones. The user created own system configurations are stored in a database.

IBP: 18599 server - for use on workstations in the office and access a central database and the project files can be saved as MS-Office documents at any point and thus be replaced.

IBP: 18599 E-CAD - additional module for 3-dimensional modelling of building with complex geometries making it easy to import to the calculation program EnEV IBP: 18599 Wienerberger Edition for comparison with energy performance requirements of the norms. In addition to the usual basic CAD functionality includes the additional module the complete graphical zoning according to DIN V 18599

There is an international module where buildings in Central Europe can be calculated according DIN V 18599. With reference to our evaluations in chapter 6.3 (calculation methodology) and brief evaluation of the software, it seems that this software is a detailed tool both for systems design/modelling and energy performance calculations, and could require substantial efforts to be adjusted to become the new software for the Contracting parties.

175 Bulgaria ENSI EAB Software There is no nationally certified Software in Bulgaria.

However, the Technical University in Sofia has been heavily involved in developing the Bulgarian calculation methodology and supporting standards, and providing training of Energy Auditors.

In cooperation with ENSI, the Technical University has developed the ENSI EAB Software, which is being used as basis for the training they offer, and is provided to the participants that pass the exam to become certified Energy Auditor.

The EAB Software is a monthly quasi-steady-state calculation method for calculating energy need and use for heating and cooling of new and existing residential and non-residential buildings according to BDS ISO 13790.

The ENSI EAB Software has been prepared for easy adjustment to different countries by entering climatic data and national reference values into each country specific version (meaning that the same calculation methodology is used in each country).

The EAB Software is complying with the basic principles of ISO 13790 and supporting standards, but some adjustments/updates are needed to fully comply with the calculation methodology as described in chapter 6.5 of this study.

The output from the EAB Software can be used to document compliance with building regulation, as input for energy certification (not producing the Certificate itself) and for energy auditing of existing buildings, including calculation of savings for each energy efficiency improvement measure evaluated.

If an existing calculation methodology in one EU Member State should be recommended, it seems that the methodology developed in the Netherlands might be the most suitable.

Another option is that the Contracting Parties establish their own calculation methodology according to the recommendations provided in chapter 6.5.

It could be efficient if a number of the Contracting Parties are defining the same methodology (just with different, national input values).

They could then cooperate on developing the calculations methodology and the national input values (common approach, gain experience) and even cooperate on getting a common software developed. Regarding energy performance calculations, it has to be decided whether to develop national software (under the guidance of a suitable public institution) or not. In some countries they have developed national software, but allows calculation with other software as long as they follow the national

176 calculation methodology (verification could be required). In other countries, it is only up to commercial market to develop and offer software according to the national calculation methodology (as the new approach in the Netherlands).

Regarding the Certification tool, this should be developed, operated and maintained under the responsibility of a relevant public body.

Besides compliance with the national calculation methodology, existing software in most countries are also tailored to the approach and actual content in the national minimum energy performance requirements and certification scheme. Since all these three elements are different country by country, and some of the calculation methodologies have not yet been updated, it is difficult to find one software to be very suitable for adjustment to the Contracting Parties. The consequence of selecting one existing software will probably be that it is necessary to update the national calculation methodology accordingly.

It might also be a challenge to rely on the commercial market quickly to develop suitable software in each of the Contracting parties.

Unless more detailed studies and investigations concludes that existing software in UK or Denmark is suitable, it is recommended that the Contracting Parties develop common software (energy performance calculations and certification tool). This might be supported by donor funds, if such applications are formulated.

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