Konstantinos Papamichael

Building design advisor: automated integration of multiple simulation tools

Abstract The Building Design Advisor (BDA) is a software environment that supports the integrated use of multiple analysis and visualization tools throughout the building design process, from the initial, conceptual and schematic phases to the detailed specification of building components and systems. Based on a comprehensive design theory, the BDA uses an object-oriented representation of the building and its context, and acts as a data manager and process controller to allow building designers to benefit from the capabilities of multiple tools. The BDA provides a graphical user interface that consists of two main elements: the Building Browser and the Decision Desktop. The Browser allows building designers to quickly navigate through the multitude of descriptive and performance parameters addressed by the analysis and visualization tools linked to the BDA. Through the Browser the user can edit the values of input parameters and select any number of input and/or output parameters for display in the Decision Desktop. The Desktop allows building designers to compare multiple design alternatives with respect to multiple descriptive and performance parameters addressed by the tools linked to the BDA. The BDA is implemented as a Windows®-based application for personal computers. Its initial version is linked to a Schematic Graphic Editor (SGE), which allows designers to quickly and easily specify the geometric characteristics of building components and systems. For every object created in the SGE, the BDA activates a Default Value Selector (DVS) mechanism that selects ‘smart’ default values from a Prototypes Database for all non-geometric parameters required as input to the analysis and visualization tools linked to the BDA. In addition to the SGE that is an integral part of its user interface, the initial version of the BDA is linked to a daylight analysis tool, an energy analysis tool, and a multimedia, Web-based Case Studies Database (CSD). The next version of the BDA will be linked to additional analysis tools, such as the DOE-2 (thermal, energy and energy cost) and RADIANCE (day/lighting and rendering) computer programs. Plans for the future include the development of links to cost estimating and environmental impact modules, building rating systems, CAD software and electronic product catalogs.

Effect of switching control strategies on the energy performance of electrochromic windows

The paper presents the results of a study investigating the energy performance of electrochromic windows under a variety of state-switching control strategies. We used the DOE-2.1E energy simulation program to analyze the annual cooling, lighting, and total electricity use and peak demand as a function of glazing type, size, and electrochromic control strategy. We simulated a prototypical commercial office building module located in the cooling-dominated location of Blythe, California. Control strategies analyzed were based on daylight illuminance, incident total solar radiation, and space cooling load. Our results show that when a daylighting strategy is used to reduce electric lighting requirements, control algorithms based on daylight illuminance results in the best overall annual energy performance. If daylighting is not a design option, controls based on space cooling load yield the best performance through solar heat gain reduction. The performance of incident total solar radiation control strategies varies as a function of the switching setpoints; for small to moderate window sizes which result in small to moderate solar gains, a large setpoint-range was best since it provides increased illuminance for daylighting without much cooling penalty; for larger window sizes, which provide adequate daylight, a smaller setpoint-range was best to reduce unwanted solar heat gains and the consequential increased cooling requirement. Of particular importance is the fact that reduction in peak electric demand was found to be independent of the type of control strategy used for electrochromic switching. This is because the electrochromics are generally in their most colored state under peak conditions, and the mechanism used for achieving such a state is not important.

Application of information technologies in building design decisions

Research and development of a new sophisticated software environment to support building design decisions are presented. This new software, the Building Design Advisor (BDA), is intended as a research tool, teaching aid and, eventually, as a practical professional tool to facilitate both strategic and detailed decision-making throughout the design process from the early schematic phases of building design through to the detailed specification of building components and systems. BDA supports the integrated, concurrent use of multiple simulation tools and databases, while allowing output to support multicriterion judgement. BDAs ultimate aims are to address the data needs of whole building life cycle analysis: design, construction, commissioning, operation, performance and demolition. Cette communication presente les travaux de recherche et de developpement portant sur un nouvel environnement logiciel sophistique destine a faciliter la prise de decisions en matieee de concepts de construction. Ce nouveau l...

A method for simulating the performance of photosensor-based lighting controls

Abstract The unreliability of photosensor-based lighting controls continues to be a significant market barrier that prevents widespread acceptance of daylight dimming controls in commercial buildings. Energy savings from the use of daylighting in commercial buildings is best realized through the installation of reliable photoelectric lighting controls that dim electric lights when sufficient daylight is available to provide adequate background and/or task illumination. In prior work, the authors discussed the limitations of current simulation approaches and presented a robust method to simulate the performance of photosensor-based controls using an enhanced version of the radiance lighting simulation package. The method is based on the concept of multiplying two fisheye images: one generated from the angular sensitivity of the photosensor and the other from a 180 or 360° fisheye image of the space as “seen” by the photosensor. This paper includes a description of the method, its validation and possible applications for designing, placing, calibrating and commissioning photosensor-based lighting controls.

Product Modeling for Computer-aided Decision-Making

In this paper, we describe the product modeling techniques that we use for the development of a computer-aided decision-making tool for the building industry. We start with an introduction to modeling and a brief description of the goals and scope of the project, and follow with an extensive presentation and discussion of the modeling techniques employed. We conclude with a brief description of our plans for the future.

Correspondence: Colour preference in lighting – A misleading name for an unscientific idea

Occasionally, a number of respected, independent scientists reach a consensus view within the peer-reviewed scientific literature that, unfortunately, is later seen as clearly incorrect. Scientists, being human, are not entirely immune to the well-known phenomenon of groupthink, which can result in errors, such as claims about ‘polywater’ in the late 1960s and ‘cold fusion’ in the late 1980s. Today, there is a widespread conceptual issue within the field of light source spectral optimization, involving the expression ‘colour preference’, which is not a defined scientific term and may be unclear and quite misleading. A keyword search of the scientific literature over the last 20 years shows that an average of about five papers per year have used the term ‘colour preference’ to describe observers’ preferences for certain distortions of surface colour appearance that are caused by illumination from light sources that have imperfect colour fidelity. An underlying and unsubstantiated assumption is that ‘colour preference’ is a measurable, objective phenomenon that is useful for optimizing the long-term value of illumination for users. As an aside, the authors have previously published work using this unclear term; in the future they will not. They feel there is no shame in unintended errors as long as, once recognized, they are not repeated. To help explain the nature of our concerns with the concept of ‘colour preference’ in lighting, we will start with an analogy about mirrors. The quality of a mirror depends on its reflection efficacy (to yield bright images) and also on its reflection fidelity (to yield undistorted images). Ensuring these aspects of quality can increase cost, so it could be helpful to study how they are valued by mirror users. One way to do so could be to ask them to compare their reflections in mirrors that have different degrees of efficacy and fidelity. In the course of such research, an interesting ‘discovery’ could emerge – a tendency for people to choose mirrors in which their reflection appears slimmer. This would be a perfectly reasonable observation, albeit one with limited usefulness. Now imagine the following unreasonable next steps: First, some researchers claim that this observation is a discovery in human perception, which they therefore give a name, ‘reflection preference’, implying that it is an important new idea, on a par conceptually with reflection fidelity. Second, they argue that reflection fidelity is an outdated idea and that in the future, mirrors should be optimized for ‘reflection preference’ – in other words mirrors should distort a person’s reflection in a slimming manner. Third, they lobby for regulations that favour the use of such mirrors in most applications. These steps would be unreasonable because (a) the label ‘reflection preference’ is incorrect and misleading, since it suggests there is a universal underlying measurable phenomenon, when there is no evidence for that; (b) there is no evidence that, in general, people would be better off with such mirrors, and there are good reasons to think otherwise; (c) because human perception is highly adaptive, short-term perception observations cannot reliably predict long-term human value; (d) the preference for a ‘slimming’ Lighting Res. Technol. 2017; Vol. 49: 285–288

Spectral Reflectivity Recovery from Tristimulus Values Using 3D Extrapolation with 3D Interpolation

We present a hybrid method for spectral reflectivity recovery, using 3D extrapolation as a supplemental method for 3D interpolation. The proposed 3D extrapolation is an extended version of 3D interpolation based on the barycentric algorithm. It is faster and more accurate than the conventional spectral-recovery techniques of principal-component analysis and nonnegative matrix transformation. Four different extrapolation techniques (based on nearest neighbors, circumcenters, in-centers, and centroids) are formulated and applied to recover spectral reflectivity. Under the standard conditions of a D65 illuminant and 1964

Fenestration systems as luminaires of varying candlepower distribution

10^{\circ}

Method for calibrating a lighting control system that facilitates daylight harvesting

observer, all reflectivity data from 1269 Munsell color chips are successfully reconstructed. The superiority of the proposed method is demonstrated using statistical data to compare coefficients of correlation and determination. The proposed hybrid method can be applied for fast and accurate spectral reflectivity recovery in image processing.

Method for preventing incorrect lighting adjustments in a daylight harvesting system

For the purposes of determining their luminous performance, fenestration systems can be considered as luminaires of varying candlepower distribution. In this way, daylighting and electric lighting analyses can be performed simultaneously, in a consistent way. An approach to determine the transmitted distribution through fenestration systems due to radiation from the Sun, sky and ground for their bidirectional transmittance is described. The approach is demonstrated using the experimentally determined bidirectional transmittance of a diffusive sample, to determine candlepower distributions under the uniform overcast, and clear sky luminance distributions.<<ETX>>