This paper reports a critical analysis of the assessment of contaminant removal efficiency. Measurements have been carried out in a ventilated room equipped with a pine wood floor, which emits Volatile Organic Compounds (VOCs), considered as air pollutants in this paper. Thereafter, Computational Fluid Dynamics (CFD) simulations are performed. CFD results are compared to measurements to check their accuracy. Moreover, air quality within the ventilated room is numerically analysed via indices.
Railway platform spot cooling has become an increasingly attractive means to improve thermal comfort conditions of existing subway stations. This paper presents a systematic approach to evaluate the effectiveness of platform spot cooling. The subway environment is first analysed by a simple onedimensional network model, which is able to estimate the bulk air temperature from the available spot cooling. The localized effects of spot cooling are then investigated using CFD.
Heat loss monitoring from a thermal manikin was undertaken representing an occupant in a classroom during a lesson period of 80 minutes in which the room temperature was increased from 21 to 24C for various airflow velocity configurations. A group of subjects was exposed to various conditions of temperature and airflow rate so that the impact of these variations on their surface/skin temperature could be determined. It was found that skin temperature remained stable and close to 34C for all conditions of exposure.
The aim of that guidebook (74 pp), published by REHVA is to provide a clear analysis of the definitions of ventilation effectiveness and to present case study examples
The definition of a good indoor climate is important to the success of a passenger rail coach, not only because it will decide its energy consumption and thus influence its sustainability but also because good comfort for long journeys is essential. A survey in a coach investigating the thermal and air quality environment was undertaken. The intention is to use the results to optimise the control of the ventilation system to provide an indoor climate that passengers will find comfortable.
In dwellings there is a desire to reduce ventilation heat loss, by reducing uncontrollable air infiltration, at the same time as providing adequate indoor air quality by controllable background ventilation. In England and Wales, the background ventilation requirements in part F of the Building Regulations at present are expressed in prescriptive terms. The adopted European Standard, EN13141-1:2004, provides a means of assessing the performance of background ventilation devices, such as trickle ventilators, and gives a standard method of measuring the equivalent area of the ventilator.
The term air conditioning not only prescribes comfort temperature and relative humidity, but also the quality of air inside the room. Indoor Air Quality (IAQ) has become a concomitant of air conditioning. The pollutants generated inside the room affect the quality of air inside the room. The major pollutants considered are occupant generated (carbon dioxide - CO2, odour), sulphur dioxide and toluene etc. The monitoring and controlling of all pollutants is cumbersome.
‘Supply air’ windows are designed with an air gap between the inner panes of glass that is used as the incoming air path for room ventilation; air is pre-warmed within the window and thereby avoids the sensation of draughts. A series of tests, verified by model simulations, were carried out to determine those aspects of the window’s specification that govern the extent to which air is pre-warmed by the windows before entering rooms.
A methodology is presented for determining the air flow rate through a stack-ventilated single-spacedenclosure bearing a roof-mounted ventilation tower. We develop a "system discharge coefficient" which takes into account the pressure losses that occur at the intake opening of the enclosure, inside the tower and at the outlet opening. The system discharge coefficient is interpreted as a reduction in the area of the path that the air flow takes. Based on this reduced area the air flow rate is then determined.
The purpose of this study was to find out the local intensity and extent of doorway draughts, the functioning of air curtains, and the variation of the neutral pressure levels in 18 industrial premises. The doorway draught can reach the whole workspace and all the employees. At the doorline, close to the doorway, the thermal conditions can be even harsher than those outside. Air curtains significantly decrease the fluctuation of the temperature at work sites, but the functioning of the same type of air curtain varied substantially between the buildings.
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