IBPSA2009

The objective of this paper is to highlight the effectiveness of light shelves in tropical office buildings to enhance interior daylighting quality. Daylight simulation was performed for custom light shelves for a typical office floor of Dhaka City in Bangladesh, to determine the best possible location under overcast sky conditions. Six alternative models of a 3m high study space were created with varying heights of light shelves. The 3D models were first generated in the Ecotect to study the distribution and uniformity of daylight in the interior space with split-flux method.

This article aims to discuss the results of the EnergyPlus daylighting module – Detailed. Because of the program relevance among the brazilian researchers and the high potential for daylighting in Brazil, it is important to evaluate whether their models for calculating daylighting are appropriate for the brazilian conditions. EnergyPlus results were compared with data measured in situ, of daylit room with windows on two parallel façades. The simulation results show weak correlation between the model output and the measured data.

The purpose of this paper is to find the efficiency of window shades regarding building energy performance and explore the possibility of developing a model that enables users to find proper shades for their specific conditions. The paper investigates different options of shades and their related variables and finds the efficiency of the shades regarding energy load. Each variable was investigated for its effect on the heat loads. Results were used as input variables for neural network prediction model.  A prediction model was developed and trained based on the previous simulation results.

The purpose of this study is to determine appropriate daylighting devices for office buildings in the city of New Delhi, India. It addresses to those devices, which are available commercially such as light shelves, anidolic light ducts, and light tubes. It intends to understand the performance of these daylight devices to their maximum potential so as to increase the daylight availability and thereby reduce the electrical lighting loads. It would further evaluate the cost effectiveness of application of these devices. Hence it assesses the rationale behind the use of such devices. 

An analysis is presented of the impact of glazing selection on building performance and daylight levels for a small office building designed to be built in Canberra, Australia.  Thermal modelling was carried out at the request of the client in order to optimise the glazing from a greenhouse gas emissions viewpoint. This paper presents the results of this thermal modelling.  A daylight model was not used at the time.

In the paper we describe an integrated building lighting and thermal simulation activities carried out in the support of EU PV-Light Project. A part of the project has focused on an experimental quantification of a moveable PV solar shading façade modules fitted to the external test cells. An experimental data has been used to calibrate building energy and daylighting simulation models. The calibrated integrated building energy and daylighting models have been used to carry out a multiple runs with the different facades options under a range of the European climate conditions.

Blind systems have been introduced to provide visual and thermal comfort, as well as to reduce energy use in buildings. A wide variety of such systems exist in terms of thermal and optical properties, location (exterior, interior), and physical configuration (size, distance between the blind slats). The current problem with blinds is that their operation is not based on the dynamics of the room (space), but on the static or manual control operated by occupants, although many studies have recognized that dynamic control can far outperform static control.

Shading device, window to wall ratio, window height, and glazing are important factors in determining building energy consumption in the tropics. This study employed the four factors in designing energy-efficient window for classroom to reduce the energy consumption for supplemented lighting and mechanical ventilation. The method was based on Ecotect simulations under some parameters, i.e.  heat gains through the building fabrics, illuminance level, and daylight factor. This study concluded that projected clerestory is the most energy-efficient window design.

Overheating in buildings not only causes discomfort to the occupiers but – if it occurs regularly or over a sustained period – also leads to pressure for the installation of mechanical cooling. In addition to the initial cost and ongoing maintenance requirements of such systems there will be an increase in the overall energy use of the building. This paper investigates the thermal performance of an industrial building (retail shed) with rooflights by means of dynamic computer modelling.

Recent statistics published by Natural Resources Canada estimates that the energy demand for heating and cooling accounts for about 60% of the total energy use of an average Canadian home. Although the overall demand for cooling energy is much lower than the demand for heating, many populated areas experience a peak demand for electricity on summer afternoons. Interior reflective window shading devices have the potential to reduce solar overheating and electricity peak demand in summer, and to improve the thermal comfort of house occupants when seated near windows.