Studies have documented that personalized ventilation, which provides clean air at each officeworkplace, is able to improve substantially the quality of air inhaled by occupants. However,the interaction between the airflow generated by personalized ventilation and the airflowpattern outside the workplaces has not been studied in detail. This paper presents a study onthe performance of a personalized ventilation system installed in a full-scale test room with anunderfloor air distribution system.
The thermal environment in vehicles varies greatly. The interaction of the cabin thermalenvironment, created by the HVAC system, the outdoor conditions as well as the occupants,is rather complex.In this regard, in order to improve occupants comfort, we thought of locally differentiatingthe parameters which influence peoples satisfaction.
The paper deals with a numerical investigation of the influence of ventilation and airconditioning on the distribution of pollutant concentrations in buildings. The model used is acoupled thermal and airflow model where the room is divided into 18 sub-zones.Temperatures and pressures are determined from the mass and energy conservation equationsin each sub-zone, while airflow rates between two adjacent sub-zones are determined from theBernoulli equation.
The airflows through a one family prototype building have been simulated. Supply openings in living room and bedrooms have a size of 200 and 400 cm2 respectively. The ventilation system is a passive stack ventilation system, with ventilation chimneys from kitchen, WC and bathroom. The following parameters have been studied: the supply opening areas and heights, the overflow opening areas between bedrooms and hall and between WC/bathroom and hall, the height of the ventilation chimneys and the opening and closing of living room and bedroom doors.
In highly insulated residential buildings, complying with the Passive House Standard, the space heat demand can be covered by air heating at air flow rates given by air quality requirements, without the need for additional air re-circulation or for a water heating system. The air distribution system is kept compact. In a common concept the supply air terminal is located above the door to the corridor. Such configurations were evaluated for typical air transfer devices and extreme supply temperatures.
An improper air distribution within air-conditioned rooms is one of the largest causes of inadequate indoor air quality and thermal comfort. A good knowledge of the phenomena allows for the advance of eventual deficiencies, thus becoming a powerful tool for the optimization of new projects or for the improvement of the operation conditions of the projects already implemented. In this study two methods were applied, one computational and the other experimental, for modelling of non-isothermal turbulent flows in airconditioned rooms. The computational model consists of a numerical
Residential distribution systems are inherently inefficient at delivering heated or cooled air to the conditioned space as the result of poor design and installation practices. Examples of some of the more common problems include heat loss/gain in unconditioned spaces and leakage through supply and return ducts. These defects can result in significantly increased energy consumption, poor thermal comfort, and high peak electricity demand. Efforts to improve distribution systems
The aim of that study was to develop a fuzzy controller for naturally ventilated buildings. This paper describes the process of designing a supervisory control to provide thermal comfort and adequate air distribution inside a single-sided naturally ventilated test room.
Variable Air Volume system use VAV boxes that serve open areas for five or more occupants, each zone is controlled with a single space temperature sensor. But VAV zone control strategies remained the same for the last years, so the designers have to consider that system : it provides a high quality environment for occupants, it permits the use of a smaller air-distribution system that is low cost and does not compromise building comfort or operating efficiency.
Air quality in conditioned spaces can be improved even in humid locations, in Florida. A field experiment in a Florida school confirmed that the use of a dual-path air-distribution system with low temperature air can maintain lower and more comfortable humidity levels.
Furthermore, that system coupled with a thermal energy storage (TES) keeps energy use as low as possible, and makes costs savings.
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