Improving the Weather

This chapter proposes an approach to thermal comfort that increases occupant pleasure and reduces energy use by connecting architecture's material and environmental dimensions. Today's dominant thermal comfort model, the predicted mean vote (PMV), calls for steady-state temperatures that are largely unrelated to building design decisions. A more recent alternative approach, the adaptive thermal comfort (ATC) model, ties comfort to outdoor conditions and individual experience. Yet reliance on HVAC technology to provide building comfort hampers how such ideas are integrated into building design. This chapter outlines the historical background of the PMV and ACT models to understand the current status of thermal comfort research and practice. It then uses four recent buildings to outline how the insights of adaptive comfort research can be translated to bespoke comforts through spatial, material, formal, and other design strategies.

Evaluation of the Impact of Window Shading on the Anti-Insulation Phenomenon in Building Energy Use

ABSTRACTBefore 2008, it was common knowledge around the world that insulation always saved air conditioning energy in buildings. In 2008 a phenomenon called anti-insulation was brought to light by Masoso & Grobler. They demonstrated that there are instances when insulation materials in a building directly increase building energy use. Researchers around the world then echoed the message. Recent work by some of the authors investigated the anti-insulation phenomenon in summer and winter for both hot climatic regions (Botswana) and cold climatic regions (Canada). Their study concluded that there is still a mystery of exaggerated sources of heat inside the building aggravating the anti-insulation phenomenon. They hypothesized that incident solar radiation through the windows could be one of the causes. This paper therefore focuses on eliminating direct solar radiation through windows by applying external shadings on a previously anti-insulation building. The energy saved is evaluated and the possible reversal of anti-insulation studied. The study is useful to energy policy makers and the building industry as it showcases the existence of a possible silent killer (anti-insulation) and demonstrates that investing large sums of money on insulation in buildings may not be the most economic thing to do in building design decisions.

THERMAL ENVIRONMENTS OF AN OFFICE BUILDING WITH DOUBLE SKIN FACADE

As a symbol of green architecture, double skin facade (DSF) represents a design which possesses many energy saving features, but due to the complexity of the system, the real performances and benefits have been difficult to predict. The objective of this study was to inform the applicability of DSFs, and contribute to the positive impacts of DSF designs. This study compared and contrasted energy savings in a temperate climate, where heating was the dominant energy strategy, and in a subtropical climate, where cooling spaces was the dominant issue. This paper focused on a university office building with a west facing shaft box window facade. The research method was a paired analysis of simulation studies which compared the energy performance of a set of buildings in two different climates. Simulation results showed a good agreement with measurements undertaken in the exiting building during a two-week period. The results specified that DSFs are capable of almost 50% energy savings in temperate and 16% in subtropical climates. Although these indicated DSFs are more suitable for temperate climates than warmer regions, the amount of energy savings in subtropical climates were also considerable. However, due to the costs of DSFs and potential loss of leasable floor area, investigations into other feasible ventilation options are necessary before final building design decisions are made.

UNCERTAINTY MODELLING OF SERVICE LIFE AND ENVIRONMENTAL PERFORMANCE TO REDUCE RISK IN BUILDING DESIGN DECISIONS

Life-cycle assessment (LCA) is increasingly used to quantify the environmental impacts of construction materials. However, the relationship between the durability and LCA of these complex products with long life-cycles must be analysed in detail, namely using stochastic data from service life prediction (SLP) studies. However, SLP uncertainty is not yet considered in LCA, thus resulting in insufficiently sound decisions at the design stage. This paper presents the modelling of the uncertainty of SLP using advanced statistical methods and its application in the estimation of SL and corresponding number of replacements of claddings (renderings and stone claddings). These results are used in an interdisciplinary study of SLP and LCA to apply in the stochastic comparison of the LCA of claddings. This methodology aids in the choice of the option with better environmental performance right at the design stage, via the comparison of their standard, deterministic and stochastic LCA results.

Solving the Problem of Multiple-Criteria Building Design Decisions with respect to the Fire Safety of Occupants: An Approach Based on Probabilistic Modelling

The design of buildings may include a comparison of alternative architectural and structural solutions. They can be developed at different levels of design process. The alternative design solutions are compared and ranked by applying methods of multiple-criteria decision-making (MCDM). Each design is characterised by a number of criteria used in a MCDM problem. The paper discusses how to choose MCDM criteria expressing fire safety related to alternative designs. Probability of a successful evacuation of occupants from a building fire and difference between evacuation time and time to untenable conditions are suggested as the most important criteria related to fire safety. These two criteria are treated as uncertain quantities expressed by probability distributions. Monte Carlo simulation of fire and evacuation processes is natural means for an estimation of these distributions. The presence of uncertain criteria requires applying stochastic MCDM methods for ranking alternative designs. An application of the safety-related criteria is illustrated by an example which analyses three alternative architectural floor plans prepared for a reconstruction of a medical building. A MCDM method based on stochastic simulation is used to solve the example problem.

Building Energy and Cost Performance: An Analysis of Thirty Melbourne Case Studies

This study investigates the energy and cost performance of thirty recent buildings in Melbourne, Australia. Commonly, building design decisions are based on issues pertaining to construction cost, and consideration of energy performance is made only within the context of the initial project budget. Even where energy is elevated to more importance, operating energy is seen as the focus and embodied energy is nearly always ignored. For the first time, a large sample of buildings has been assembled and analyzed to improve the understanding of both energy and cost performance over their full life cycle, which formed the basis of a wider doctoral study into the inherent relationship between energy and cost. The aim of this paper is to report on typical values for embodied energy, operating energy, capital cost and operating cost per square metre for a range of building functional types investigated in this research. The conclusion is that energy and cost have quite different profiles across projects, and yet the mean GJ/m2 or cost/m2 have relatively low coefficients of variation and therefore may be useful as benchmarks of typical building performance.