English

Building energy systems often consume 20% more energy than is necessary due to system deviation from the design intent. Identifying the root causes of energy waste in buildings can be challenging largely because energy flows are generally invisible. To help address this challenge, we present a model-based, whole building energy diagnostics and performance monitoring system.

This study proposed the Tikhonov regularization strategy coupled with the least-squares optimization to identify unsteady gas release processes from a fixed spot. The Tikhonov regularization adds a regularized term to the optimizing objective function and imposes a bound to solution. To accelerate the solving procedure, the unsteady gas concentration is calculated as the convolution integral between the concentration response by a unit impulse release and the arbitrary unsteady release.

This paper describes the basic features of a new advanced human thermal model (HTM), which is integrated with a building simulation tool. The thermal sensation calculation of the model has been validated using dynamical temperature step change test results. This new methodology seems promising, and significance of both internal (metabolic rate and clothing) and external (air and surface temperature levels, air velocity, and humidity) boundary conditions can be estimated. This is beneficial, for example, when evaluating new technical concepts for future energy-efficient buildings. 

This paper presents the evaluation of energy and exergy performance of several design alternatives of residential heating systems for a house. All component-based models, written and solved in the Engineering Equation Solver (EES) program, are assembled in several design alternatives for the heating, ventilation and domestic hot water (HEAT-DHW) systems. An energy-efficient house in Montreal is used as a case study.

This paper reports on research that uses building performance simulation and uncertainty analysis to assess the risks that projected climate change poses to the thermal performance of buildings, and to their critical functions. The work takes meteorological climate change predictions as a starting point, but also takes into account developments and uncertainties in technology, occupancy, intervention and renovation, and others.

Advanced control systems are widely applied in modern buildings so as to meet the requirements of energy conservation and higher level of indoor environmental quality. The building control strategies need to be assessed and verified before applying to buildings, by either experiments or simulation. Verification by simulation can saves time and labour. However, there is no single building performance simulation tool that offers sufficient capabilities and flexibilities to accommodate the ever increasing complexity and rapid innovations in control systems and technologies.

This paper investigates the inclusion of passive airflow components such as solar chimney, and wind induced earth air tunnel into a coupled multi-zone ventilation and thermal model. Existing commercial coupled multi-zone ventilation and thermal modelling software do not include passive airflow components, which need a simultaneous prediction of temperature and airflow rate in the components. The present model is compared with the coupled COMIS-TRNSYS software for lightweight buildings with large openings and both the thermal and airflow prediction match with good accuracy.

In this paper, the application potential of ground-coupled heat pumps (GCHP) in a multi-storey office building in Hong Kong was investigated.  It was found that within the limited land area occupied by the building, the GCHP could only handle the cooling load for one floor over a range of the ground thermal conductivities and undisturbed ground temperatures.  The year-round energy consumption of the GCHP was compared with those using the conventional vapour-compression chiller systems.

New façades of high-rise buildings often include renewable energy converters to allow “green building” operation. At the same time, numerous tenants value visual transparency. Transparent solar thermal collectors (TSTC) aim at decreasing the non-renewable primary energy (NRPE) demand and increasing the visual transparency at the same time. On the one hand, this paper presents the main modelling challenges that arise when considering building façades and especially integrated TSTC systems. New TRNSYS Types have been especially developed for this purpose.

The Sustainable Buildings Research Centre (SBRC) currently under development at the University of Wollongong will be an exemplar in respect of demonstration of a range of technical and operational means of reducing greenhouse emissions and other ecological impacts. This paper details the constraints and opportunities presented to the project in terms of renewable energy production and minimization of building energy consumption. The building performance was simulated using variety of tools for a range of ventilation and air conditioning options.