Zonal models have been proposed to bridge the gap between the whole-building macroscopic modeling methods of programs like CONTAM or COMIS and the more detailed microscopic modeling metho.ds based on solutions of the time-smoothed Navier-Stokes equations for room airflows. This paper identifies a critical shortcoming of conventional approaches to zonal modeling by introducing alternative approaches a) to formulate the key cell-to-cell flow relations upon which zonal models are based and b) to assemble the zonal system equations.
The authors were asked to investigate the dynamic thermal performance of a winery building designed by Architects Freebairn-Smith & Crane. The objective was to evaluate the effect of the building fabric (particularly the strawbale wall construction) in moderating the impact of climatic variation on the internal environment in order to assess the need for auxiliary heating or cooling in the different areas of the building to achieve the thermal stability required particularly in the barrel storage room. A comparison is made with a fully serviced reference building.
In many hot countries courtyard housing has evolved to help people achieve thermal comfort under hot conditions. Field studies have identified several thermal comfort adaptive actions that a person might take to achieve comfort. One of these actions is moving to a different thermal environment from the one causing the discomfort. The present paper examined how people adapt themselves thermally to achieve comfort in Iranian courtyard housing by moving between different spaces .in the house during the day.
The protection of non-smoking persons against cigarette smoke is a very popular subject. In Germany the ,pro' and , contra' of non-smoking regulations especially in public accessible areas like restaurants, train stations or in governmental buildings is discussed in a more and more controversial way. Especially the discussion about passive smoking and negative health effects through passive smoking lead to the demand of an effective protection of nonsmokers.
The evolution of the temperature profile in a warm room driven by a natural ventilation flow which develops when the room is connected to a cold exterior by two openings at different vertical heights is explored. With the openings at the top and base of the room, we find the classical displacement ventilation regime provides a leading order description of the flow. With openings at the centre and top of the room, the ventilation is hybrid, with the lower part of the room being well-mixed, and the upper part being stratified by an upward displacement ventilation flow.
Large eddy simulations (LES) were performed for flows relevant to or incurred in ventilation air motions with and without thermal effects. The emphasis was placed on the discussion of the possibility and potential of LES for modelling indoor air flows. Some prospective views were given on the capability and implementation of the LES approach. LES is a potential tool for providing detailed and accurate solution of turbulent flow and heat transfer in analyses of indoor environment and building energy performance.
In this study the spatio-dynamic temperature response in a ventilated room to variations of the supply air temperature was modelled for a wide range of ventilation rates. The model structure was first formulated by applying standard heat transfer theory to zones of better mixing. Spatio-temporal temperature data were then exploited in statistical terms to estimate the physically meaningful model parameters. The dynamic model yielded an excellent fit to the experimental data and was found to characterise the spatially heterogeneous nature of the air flow pattern quite well.
When it is required to predict the local mean age of air, the calculations are often carried out assuming that there is no recirculation that is that all of the supply air is fresh. However, local mean age values will be greater than in the fresh air case when some of the exhaust air is recirculated. This paper examines and discusses the effect of recirculation and shows that, for many systems the increase in local mean age due to recirculation can be calculated by means of an elementary analysis that leads to a simple algebraic expression.
This paper presents an innovative roof design. The roof is designed in response to the Tropical climate of Thailand with respect to human thermal comfort. It is composed of a combination of CPAC Monier concrete and transparent tiles on the outer side, air gap and another combination of gypsum with aluminum foil board and translucent sheets on the house side. It has two functions in operation: In daytime the roof acts as a solar chimney and induces natural ventilation. The transparent tile provides not only ,sufficient daylight for housing but also help in increasing the ventilation rate.
Login