The peak electrical demand of office building VAV systems will be reduced by about 1.2 Kw/1000 Ft2 by employing an Integrated Systems Demand Control Technology (ISDCT) sequence to reduce peak intake flow by about 56%.Supply, return, and exhaust fan energy decreases with reduced airflows and pressures; and chiller system energy is saved by reduced cooling coil loads.The ISDCT sequence continuously computes zone contaminant concentrations allowing compliance with reference standards.
In this work two numerical models are presented. The first one simulates the buildings thermal response and evaluates the internal air quality, while the second one simulates the human and clothing thermal systems and calculates the thermal comfort level in non-uniform environments. The results obtained by the first model are used as input data in the second one.
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
Condensation and mold problems have been identified as one of the severest IAQ problems in Japan. Especially in the wintertime, moisture condenses on cold wall surfaces where it can cause deterioration of the building materials and mold growth related to allergic symptoms. This paper discusses the possibility of using the CFD method to solve condensation problems.
Firstly, a CFD model for simulating condensation is developed, and then the validity of this model is examined experimentally.
The balance between the energy efficient thermal comfort and Indoor Air Quality (IAQ) in healthcare facilities is the main of this paper. The present paper will present this balance from the viewpoint of the air conditioning design. It was found that the design of the HVAC airside systems plays an important role for the energy consumption optimizations and achieving the optimum IAQ. This paper highlights the importance of the proper airside design on the energy consumption, thermal comfort and IAQ.
The present paper addresses and fosters the factors that affect airflow movement and energy efficiencies in the surgical operating theatres. The present work puts forward analyses for major factors contributing to failure to achieve and attain the optimum Indoor Air Quality (IAQ), and the methods suggested to solve such problem. Appropriate architectural and mechanical engineering recommendations to achieve the optimum hygienic operating theatre are set out in the paper.
For that study, a classroom was modelled and a comparison of the performances of a specific hybrid ventilation system with a traditional mechanical system in terms of thermal comfort, indoor air quality concerning the CO2 concentration and energy consumption was made. The experiment was performed in different French cities, it permitted to draw some conclusions about the potential of such an hybrid system according to the main climate characteristics.
This article is a study of the air quality at a bus terminal. Presence and concentration of indoor air quality indices were determined by field surveys and sampling. Bus emission rates, occupational exposure and ventilation requirements to have a correct indoor air quality were simulated by mathematical model.
The results show that the natural ventilation rates are too low for having a good indoor air quality, and that pollutants emission varies with the temperature.
A survey was carried out in 16 libraries in Modena University (Northern Italy) to assess the indoor exposure to Volatile Organic Compounds. VOCs were present in all the investigated libraries.The conclusion of that study is that no major problems were related to indoor pollution but the identification of the possible sources of contaminants is important, just as a definition of the relationship between indoor and outdoor levels of pollutants : that will take into account the effects of air recycling due to natural ventilation systems.
This paper proposes a space zone model for the calculation of all the airflow parameters based on tracer gas measurements, including flow rates of outdoor air, VAV supply. This approach gives a practical protocol for buildings managers to evaluate the performance of airside systems and determine air-conditioning and ventilation system performance parameters within acceptable errors.
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