Model uncertainty and sensitivity analysis for thermal comfort prediction

Building Performance Simulation (BPS) is poorly used to support informed decision making between different design options nor is it used for building and/ or system optimization. Currently BPS is only used for code compliance during the detailed design [Wilde, 2004]. The approach of this research by using an existing tool as initial prototype is rapid prototyping to make incremental improvement of BPS. This paper elaborates the above in more detail in particular by focusing on an uncertainty and sensitivity analysis for thermal comfort prediction. A case study is described to evaluate the necessity of the use of uncertainty and sensitivity analysis in BPS. For that purpose an in the Netherlands well-known and commonly-used simulation tool for the detailed design is chosen. Furthermore, a range of results reflecting the impact of UA and SA are presented

The impact of future climate scenarios on decision making in building performance simulation: a case study

Expected climate change may turn into a key challenge for building designers in the 21st century [Homes et al. 2007].In response to this challenge simulation packages have started to provide future climate scenarios to predict the energy demands and thermal comfort in buildings. The need to make predictions for climate change scenarios is becoming increasingly important.This paper describes the integration of climate change scenarios in one of the building performance simulation tools, i.e. VA114, which is used extensively in the Netherlands. Based on the existing traditional reference year "De Bilt 64/65", NEN 5060:2008 released a new norm that introduces four new climate files for different types of climate adjustments. KNMI on the other hand assembled four different future scenarios for the expected climate change. The climate files from the NEN and the KNMI future scenarios have been combined in a future climate data analysis for usage within the targeted simulation software VA114. The paper describes a case study focusing on the impact that a climate scenario may have on a concrete design decision. The case study involves two HVAC system designs: (1) a conventional cooling/heating system and (2) a heating/ cooling storage system. Both options are simulated and compared. The impact of climate change is shown on energy use and thermal comfort. It is then shown how the climate scenarios (and their inherent uncertainties) impact the uncertainty in the outcomes and how these outcomes influence the choice between the design options. The conclusions of the paper highlight the relevance of different (uncertain) climate scenarios and the role they play in design decision making

A comparison of measured and estimated electric energy use and the impact of assumed occupancy pattern

The use of building performance simulation (BPS) tools to guide decisions during the design process in its early stages requires making assumptions. That is as the design specification, information about building use and future external climate are not available. This may lead to differences between the buildings performance in operation and its predicted performance. The aim of the presented work is to assess the impact of the building use on observed differences in performance. Parameters of concern are occupation period, occupancy density, electrical energy use and sensible heat gains from equipment and light fittings. The results of the study show that the difference between estimated and measured local electric energy use is below 10%. The important parameters related to the office use are identified as occupation period and heat gains from light fittings. In case of the considered building the use of medium high internal heat gains would have lead to overestimating the cooling demand by 30%. The identified parameters should be considered with great care when using BPS–tools for guiding the design of office buildings as they contribute significantly to the accuracy of simulation results

Klimaatscenario's in gebouwsimulatie-programma's : eerste gebruikservaringen

Bij het ontwerpen van gebouwen wordt gebruik gemaakt van gebouwsimulatieprogramma’s om prestaties op het gebied van comfort en energiegebruik te voorspellen. Het buitenklimaat wordt in deze simulaties meestal gerepresenteerd door klimaatbestanden met uurlijkse waarden voor de weergegevens. Tot op heden werden hiervoor de historische gegevens van De Bilt gebruikt van het jaar 1964-1965, omdat dit werd gezien als een gemiddeld jaar met voldoende extremen. De vraag rees of dit bestand na 40 jaar nog geschikt is om te gebruiken. Een NEN-commissie is vervolgens gaan werken aan nieuwe referentiebestanden, gebaseerd op gemeten weergegevens van de laatste 20 jaar, 1986 tot 2005 [1]. Het resultaat, vastgelegd in de ontwerpnorm NEN 5060:2008, bevat vier verschillende referentiejaren voor verschillende toepassingen

Development of a thermal storage system based on the heat of adsorption of water in hygroscopic materials

A thermal storage system based on the heat of adsorption of water in hygroscopic materials has been studied as a component of a solar space heating system. The aim of this project is to decrease the storage volume in comparison with a rock-bed storage system by increasing the stored energy density

Distributed building performance simulation : a novel approach to overcome legacy code limitations

This paper describes the development of as well as implementation strategies for distributed simulation of building systems by run-time coupling of existing software. The approach differs from the traditional way of developing software in which additional models are added by incorporating new modules into an existing program. This paper focuses on the actual coupling mechanism. A case study is presented that illustrates the need and potential of the approach. The conclusion is that a distributed simulation environment is more flexible, practical, and powerful than the sum of the individual software programs

Model uncertainty and sensitivity analysis for thermal comfort prediction

Building Performance Simulation (BPS) is poorly used to support informed decision making between different design options nor is it used for building and/ or system optimization. Currently BPS is only used for code compliance during the detailed design [Wilde, 2004]. The approach of this research by using an existing tool as initial prototype is rapid prototyping to make incremental improvement of BPS. This paper elaborates the above in more detail in particular by focusing on an uncertainty and sensitivity analysis for thermal comfort prediction. A case study is described to evaluate the necessity of the use of uncertainty and sensitivity analysis in BPS. For that purpose an in the Netherlands well-known and commonly-used simulation tool for the detailed design is chosen. Furthermore, a range of results reflecting the impact of UA and SA are presented