In this study a parametric analysis was carried out of the interaction between louvres and various perforated mesh screens. This type of arrangement is common in through-the-wall ventilators used for natural ventilation in buildings. An airflow testing rig was used to examine the impact on louvre airflow performance of the meshes. The interaction of louvre geometries and blade inclinations with meshes of different hole sizes was also investigated experimentally.
This paper is an overview of the work carried out during a 3year EPSRC funded project investigating the important factors in Supply Air window design. The structure and some of the main conclusions of this work are presented here. The project consisted of alternating experimental and simulation phases; the experimental results contributed to the model validation, and the simulation outputs provided design guidance for the following experiments.
European project pr EN13465 from CEN TC 156/WG2/AH4 gives a monozone model for airflow calculations in dwellings. In order to apply it to natural ventilation systems with adjacent ducts used in dwellings in France, we need to address several issues. First, in adjacent ducts, airflows at each level depend on pressions in the different dwellings. We have to solve by iteration the balanced equation proposed in AH4. Then, cowls and roof outlet performances as well as the wind-pressure coefficient on the roof must be known.
Increased global warming and deterioration of the ozone layer have stimulated interest in the use of renewable energy systems. Natural ventilation is increasingly being employed in modern buildings to minimize energy consumption and the release of harmful emissions to the environment. Innovative natural ventilation techniques such as the windcatcher and solar chimney have facilitated the effective use of natural ventilation in a wide range of buildings for increasing the ventilation rate.
The "Intelligent Facade" is seen as a central element in the evolution of building form and building fabric to provice environmental control and comfort. Describes the background of bioclimatic architecture and goes on to give an outline of the subject of intelligent skins for buildings. Provides two examples of the case study review which has been performed.
In this paper, measurement and simulation results are presented that demonstrate the energy performance of a recently built ecological house in Helsinki, Finland. The space heating energy consumption was measured to be 76 kWh/(m 2 a) of which 29% was provided by wood. For comparison, Finnish houses typically consume 120 kWh/(m 2 a) or nearly 60% more energy for space heating. The total energy consumption (121 kWh/(m 2 a)) and electricity consumption (28 kWh/(m 2 a)) were quite low.
The aim is to develop a new method for comfort in settings with high thermal load in buildings that do not require continuous cooling but cooling only during shorter periods. Example of such buildings is schools. The present ventilation and control systems are designed for supply of air at a constant flowrate or to respond to relatively slow variations in load or step changes in load. The slow variations in load are mainly governed by the diurnal cycle and sudden step changes in load are mainly due to people entering or leaving a room.
The paper reviewed the supply opening models of describing inlet boundary conditions for indoor airflow simulation firstly. Then examples of isothermal free air jets from a grille are presented to validate full representation of supply openings. Some results by the simplified method called N-point supply opening model, are also shown to compare with the full representation method. Four different outlet conditions of a grille are studied. The k-e turbulence model is applied.
When studying improvements on room by room air conditioning appliances (RAC), it is necessary to know for how long these appliances function and which is their effectiveness - EER - on average (or Seasonal) known as SEER. A method was developed for Europe, taking into account the cycling losses, the fouling losses and the variations due to outside temperature and humidity. Further to this the load was represented by an equivalent number of hours at full load.
Thermal bridges are the typical locations for moisture and mould problems in buildings. Low surface temperatures in combination with a high humidity level in buildings can lead to severe problems and complaints by the occupants. Thermal bridges lead also to a significant increase of the energy losses in well insulated buildings. At present, thermal bridge problems still frequently occur in new buildings but especially in rehabilitation projects. In several countries so-called thermal bridge atlases already exist.