IBPSA2013

This study presents 2D numerical simulations of natural ventilation in a room equipped with two openings, one low and one high. The main features are commented in terms of flow and heat transfer. We first focus on pure natural convection within the framework of the ADNBati benchmark, and validate the numerical model this way. Then we study the transition to adverse forced convection (the flow is eventually reversed) and highlight the main changes due to transition. Lastly, we present a method for coupling CFD simulations with a multizone model. 

In the framework of the MEGAPICS project “method toward guarantee of solar cooling and heating system”, a simplified pre-design tool for designer and planner has been elaborated.  The method is applied to a selected set of configuration schemes for solar cooling, heating and domestic hot water (DHW) production systems using absorption or adsorption chillers, assisted or not by hot and/or cold conventional back-up systems. The tool provides theoretical but realistic values of system performance indicators. Its main advantages compared to other tools are:

Weather normalization is a crucial step in building energy rating and retrofit measurements. Accounting for the impacts of weather on energy use of commercial buildings is a rigorous challenge because of the complexity and diversity in the operation, the mechanical systems, and the use-types available. This paper documents preliminary results of an effort to determine a set of weather adjustment coefficients that can be used to isolate the impacts of weather on energy use of buildings in 1020 weather location sites available in the U.S. The U.S.

  A new methology using agent-based modeling for human behavior simulation is presented. This approach aims to address the limitations and/or challenges of dealing with behavioral components in existing building simulation programs. Also, it tries to improve behavior decision process by mimicking actual occupants in buildings. In a simulation experiment, a window use behavior was tested with agent-based modeling and demonstrated its ability to account for dynamic changes of the behavior, in real-time, and the behavior impact on both the microclimate and energy uses in a space.  

To produce a realistic building reference’s model, in order to work on a retrofitting project, input data have to be chosen with the field’s information. The present work concerns French residential buildings of the pre-world-war-II family. This category is more and more subject to retrofitting project and represents more than 30% of the French building sector. In addition, the old buildings are characterised by difficulties to collect data.

This article presents a comparison between experimental and numerical results in terms of coupled hygrothermal behavior. The measurements were taken on an experimental wooden-frame house located in France. Several sensors were installed in the room and in several locations inside the walls. The external climate was measured as well. Numerical simulations were performed with the EnergyPlus tool and its algorithm for combined heat and moisture transfer, available since September 2011. First, the simulated and measured values were compared for temperature and humidity in the walls.

The inherent feature of fixed inner volume ratio of the scroll compressor causes large degradation of the compressor’s indicated efficiency when the inner compression ratio mismatches with the system compression ratio under the off-design condition. The inner compression ratio adjustment technology, such as refrigerant injection and refrigerant release, can enhance the seasonal efficiency of the compressor and the air conditioner. An inverter air conditioner with inner compression ratio adjustment is proposed in this paper.