IBPSA2013

Recently façade systems have integrated passive solutions to reduce the energy consumption in buildings and improve their occupants’ comfort. This paper reports the results of the thermal performance of Trombe walls and daylighting of glazing modules of a façade system in Portugal. Trombe walls are massive walls separated from the outdoors by glazing and an air space, which absorbs the solar energy and releases it selectively to the inside of the building at night. Computational simulations were carried out with the Design Builder, Ecotect and Desktop Radiance programs.

Traditional uncertainty quantification (UQ) in the design of energy efficient buildings is limited to the propagation of parameter uncertainties in model input variables.  Some models inside building simulation are inherently inaccurate, which introduces additional uncertainties in model predictions. Therefore, quantification of this type of uncertainty (i.e., modelling, or more strictly speaking model form uncertainty) is a necessary step toward the complete UQ of model predictions.

In the context of district energy systems, changes in a building’s heat demand also affect the energy efficiency of the whole district heating network. We present an integral dynamic model of a district heating network branch with three buildings. By comparing simulations of a reference case and a retrofit scenario we show that reducing the buildings’ heat demands also reduces the mass flow rate in the network branch.

The use of LEED as a building sustainability rating method is well established in the US. In this paper we concentrate on the calculation of the score in the Energy and Atmosphere category of LEED, i.e. the LEED-EAc1 score. Its calculation is based on an adaptation of the ASHRAE 90.1 calculation method. This paper will argue that the approach is needlessly complicated and laborious because there are simpler, non-simulation based methods that may be equally adequate for the energy rating of a building.

We investigate the possibility of using geothermal hot water in heat-driven cooling systems, for air conditioning in tertiary buildings in Belgium. Models of two possible cooling systems and of three tertiary buildings are developed in the TRNSYS environment. Results show that hot water temperature level and waste water regulations complies with desiccant cooling system, provided that the fresh air flow rate, related to the occupancy profile of the building, matches the process air flow rate of the cooling system.