IBPSA2015

Attic spaces belong among the most popular forms of housing or working. The most common reasons why people prefer this form of living are for example the efficient utilization of the land, lower costs of utility connection, better contact with environment and that it has a very positive impact on the human well-being. Thanks to the sloped window plane the daylight distribution inside of these spaces is very specific. In addition, they are critical regarding to overheating during summer period, so it is also necessary to analyse them in terms of thermal comfort.

The scientific literature offers a number of methods for assessing the likelihood of overheating in buildings. The paper calculates eight welldocumented indices for four representative family houses, from moderate and temperate climates, under different renovation processes (66 variants), with the use of multi-zone energy software. In two out of four cases, the calculation included passive cooling measures for optimization purposes (shading, ventilative cooling).

In the absence of thermal comfort standards in India, architects and designers have no choice, except to provide air conditioning to meet thermal comfort criteria for achieving green building rating for their projects and thus end up using more energy eventually. Significant Energy saving can be brought about by promoting naturally ventilated buildings as thermally comfortable building by retrofitting them with energy conserving measures for improving thermal performance.

This paper evaluates the influence of underground piping on the performance of using increased thermal capacitance (ITC) as a passive energy management system on an office building. The building’s cooling load will be decreased by circulating water from a storage tank through underground piping then through a piping system located in the building’s ceiling. The cooling load of an ITC enhanced building with underground piping is compared to the cooling load of an ITC enhanced building without underground piping and a reference building without ITC at all.

The paper presents an application of a new method to simplify models of heat sources in CFD simulations of large spaces exposed to variable occupancy patterns. The previously developed approach is applied in a real scenario of a recently refurbished former church built in 14th century, now used as a concert and conference hall with up to 350 visitors staying for different period during each day.

Appropriate building design for natural ventilation can reduce discomfort, while saving energy on airconditioning. Parametric building simulation analysis for natural ventilation typically consists of several design variables and input parameters with uncertainty, making it computationally intensive. For optimizing the building design within a reasonable timeframe, design of experiment techniques based methodology is proposed. Firstly, the significant design variables and input parameters are identified.

Simulations were conducted to optimize the design of a small building with walls constructed of limestonefilled gabion baskets. Different methods of insulating and weatherproofing the gabion walls were compared, with the indoor operative temperatures in the summer design week providing the critical comparison. The performance of the gabion building was compared with that of more conventional construction types to demonstrate the superior thermal performance of gabions in a temperate climate (Australia). This paper also addresses an issue with simulating gabion walls.

This paper presents an analysis of internal air temperatures measured hourly in the living rooms of 10 domestic buildings in the city of Leicester, UK. Time series analysis is used to develop empirical models of room temperatures in rooms that are neither mechanically heated nor cooled, during the summertime period of July and August 2009. The models are used in predicting future temperatures based on past measured values. Such models can enable overheating risk alerts for homeowners and public authorities to be more accurately estimated and targeted. 

The paper presents a numerical methodology to assess wind pedestrian comfort and natural ventilation in urban areas. UrbaWind, an automatic computational fluid dynamics code, is improved to model the wind in dense urban environments. The turbulence modelling, that is to say the dependence of turbulence length on the distance from wall, and the model constants are calibrated in order to reproduce precisely flow separation around buildings walls. Numerical results match well with the experiments: separation patterns, pressure field on walls, and wind speed in dense urban area.

Building performance simulation has been utilised for the investigation of thermal comfort and airflow within a naturally ventilated, self-sufficient house in a bushfire prone area. Lightweight construction with Phase Change Materials (PCM) was proposed as an appropriate solution to respond to the brief. The simulations modelled the effects with and without PCM, to demonstrate the reduction in temperature swings throughout design days.