Support for the integration of modelling in the Energy Performance of Buildings Directive

Georgios Kokogiannakis

Energy Performance of Buildings Directive (EPBD)

EPB Directive 2002/91/EC:Proposal published on 11 May 2001Came into force on 4 January 2003On January 2006, Member States have to put the

Directive into practice through their own legislation Objective: promote the cost-effective improvement

of energy performance of buildings

Energy Performance of Buildings Directive – why? Europe is worried about the security of Energy

Supply Kyoto protocol obligation to reduce greenhouse

gas emissions Limited impact on supply but potential savings

on demand and mainly at buildings

Energy Performance of Buildings Directive – what? Calls for a common methodology for an integrated energy performance of buildings based on technical annex

…integrated……integrated…

Energy Performance of Buildings Directive – what? Calls for a common methodology for an integrated energy performance of buildings based on technical annex

…integrated……integrated…

Sustainability & Directive

Does the Directive cover the set of aspects that society is interested in during the sustainable design of buildings?

How is it going to evolve?

Sustainability & Directive

Acoustics, Local thermal & visual comfort, contaminants concentration, surface condensation, e.t.c….

Integrative modelling

Buildings:Systematic (many parts make the whole)Dynamic (the parts evolve at different rates)Non-linear (the parameters depend on the

thermodynamic state)Complex (myriad interactions)

Integrative modelling

Preserves the integrity of building/plant system Cheaper & quicker feedback on alternative

design approaches Large number of assessment under realistic

conditions

Methodology in UK

Domestic buildings:Simplified methods (SAP2005 in England and

Wales, SERT in Scotland)

Non-domestic buildings:Detailed thermal modelling softwareNew simplified tool (NCT) based on the Dutch

Standard NEN 2916:1998

Which method? Is a simplified method enough to cover

appropriate the building sustainability issues? What are the dangers of using such a method? If modelling:

How should users select modelling tools?

Case studies Two modelling tools (ESP-r & EnergyPlus) Simplified method Dutch Standard NEN 2916:1998

Base Case

• Change orientation

• Change constructions

• Change occupancy patterns

• Change climate

• Change ventilation strategies

• Change shading strategies

• Heating and cooling loads

• Daylight & glare

• Peak & Mean Air Temperatures

• Overheating risk

• Thermal comfort

• ……

Case studies Inability of the simplified method to deal with

some of the assessments Simplified method – not “simplified” for use Simplified method produces different results

than the two modelling tools Differences in some cases between the results

of the two modelling tools

Software accreditation “Online” validation: Embedded validation tests in

the modelling tool (ESP-r) Users can access & choose testsRun them automatically with pre-defined

parameters Results analysis is automatically invoked Specific results for every test are recovered and

saved in a file…

Software accreditation “Online” validation: Embedded validation tests

in the modelling tool (ESP-r)ESP-r reads a recovery data file A check is made whether or not the recovered

results are within the specified rangeResults from the previous released version or

another version of the past are also displayed

“Online validation” - Benefits

Developers can check the impact of code modifications

Developers can check compliance with regulations

Frequent checking will confirm the fact that a program continues to be within the specified tolerance bands

“Online validation” - Benefits

User confidence is improved Users can confirm their installation is correct

and check Standards compliance themselves No need for repeating the construction of the

models set out in the validation tests

Summary EPB Directive is a good first step Expected to evolve to cover more sustainability

issues Need for a methodology that integrates these

issues Modelling exists and has the capability to deal

with these issues Accreditation process needed “Online validation” can offer useful benefits