First laboratory experiments are presented, the aim is to examine the transient filling of a room of buoyant fluid when a doorway connects the room to a large reservoir of dense fluid. A model of the transient exchange flow is then presented, it is in accordance with the experimental results.
A layer of air, warmer than the exterior must be maintained above a cold layer near the floor to prevent the heat supplied to the room to be lost through the doorway.
The simulation of airflow pattern in an office building in Singapore is based on the environmental conditions and the corresponding ventilation parmeters measured on a typical day. The findings of that study are reported in this paper.
The author asserts that to maintain a good indoor air quality, both ventilation and reduction of the pollutants sources are necessary. Standard 62.2 defines the minimum requirements about ventilation for an acceptable indoor air quality, but does not deal directly with the sources of pollutants. So the author gives an inventory of the main indoor air pollutants and how to cope with them. He maintains that the treatment of the pollutants at their source is very often the best way to keep a good indoor air quality.
In a VAV system, it is possible to minimize the energy use with an optimal supply air temperature. The theory for such a device is presented. The analyses show that controlling the supply air temperature in an optimal way results in a decrease of HVAC energy use compared with a constant supply air temperature.
A supply air window enables the pre-heating in winter of ventilation air before it enters the room.The window device must entrain into the room the air flow that would otherwise escape, it allows the absorption of the solar radiant energy and a low emissivity coating within the glazing assembly must be correctly located. To achieve a better performance of the window, tests were carried out. A simulation model was built and comparison of the results were made.
This paper is a clear presentation of the different available systems to ensure a good thermal comfort : the author starts with passive systems that maintain comfort without an extra energy consumption, carries on with the low-energy consumption systems that allow air refreshment ,
then refreshing floors and cool ceilings and low-speed ventilation are described , he ends with
air-handling devices to be installed in residential or collective housings.
This paper presents the latest edition of the standard 62.1. It combines the 62.2001 version with 17 approved addenda, all of them have been approved by both Ashrae and ANSI. The most significant changes involved the ventilation rate procedure, minimum ventilation rate table and outdoor air treatment requirements.
That document is easy to use for designers, code officials and others users .
That standard is continuously reviewed and revised through addenda to keep up with new research findings and experience from the field.
This paper describes a pilot study conducted in an occupied family house in Ohio to determine if a script-based protocol could be used to obtain data useful for the identification of the key factors affecting air-exchange rate (AER) and the relationship between indoor and outdoor concentrations of selected traffic-related air pollutants.
Ultraviolet germicidal irradiation (UVGI) systems are used to disinfect air, they consist in mounting shielded UVGI lamps at high level in an upper room zone, and the natural convection currents that occur in a room space carry airborne microorganisms through the UV field. This study demonstrates that the effectiveness of those systems is dependant on both the ventilation regime and the in-room air mixing.
The aim of that study is to establish characteristic building parameters and to analyse the night ventilation effect with these parameters. Measurements were made thanks to a parametric model and a building simulation programme.
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