This article aims at providing an overview of recent field experience, as reported in the literature, about underfloor air distribution systems (UFAD) as an alternative to conventional air distribution.
This paper reviews the flow network model based on power balance as applied to wind-induced cross ventilation in a residential building. The characteristics of wind-induced cross-ventilation with open windows in buildings are different from those of air infiltration through cracks in walls. The features of the velocity and pressure distributions are apparently different. In cross-ventilation, it seems that a kind of stream tube is formed through the building.
Toxicologically derived guidelines for the evaluation of VOC concentrations are still sparse.Therefore a schema is proposed for establishing target or intervention values which includesfollowing basics: i) Guidelines are derived from statistical values of representative studies. ii)Guidelines should refer to standardized analytical methods. iii) Guidelines should exist for allvolatile indoor air contaminants. iv) Possibility of dynamic adaptation, if the VOC mixturechanges. v) Up-to-dateness. vi) TVOC concept and values for groups of VOC should beincluded.
This paper is a review of occupant responses to localized (floor and desk mounted) airdistribution systems. These systems offer personal control, and can produce good ambientconditions, but few studies have examined their effects on actual occupants. A review ofeleven studies suggested these systems can lead to favourable occupant responses, which insome cases exceed those encountered using traditional mixing systems. However, most of thestudies included methodological limitations, which reduce the strength of conclusions that canbe drawn.
In this paper, the very recent laboratory research results on personalized air supply (PAS)from three universities are critically reviewed. Based upon these experimental results, thepotential improvements on inhaled air quality versus indoor air quality are analysed in termsof reduced air pollutant levels in the inhaled air. Depending on the configuration of the PAStested, up to 80% reduction of pollutant levels in the inhaled air can be achieved at the sametotal ventilation rate of the present mixed ventilation methods.
This paper reviews the previous attempts to evaluate the Indoor Air Quality (IAQ),investigates previously proposed IAQ factors and analyses the evaluation methods of thesefactors. The present work also introduces a new hypothesis of the optimum HVAC airsidesystem design of the surgical operating theatres to achieve the comfort and hygiene levels.The present work is devoted to propose and formulate a new scale capable of adequatelyevaluating the airflow pattern in the surgical operating theatres. The proposed new scale isproposed to cover the local and overall air quality evaluations.
The relationship between indoor and outdoor concentration levels of particles in the absenceand in the presence of indoor sources has been attracting an increasing level of attention.Understanding of the relationship and the mechanisms driving it, as well as the ability toquantify it, are of importance for assessment of source contribution, assessment of humanexposure and for control and management of particles.
Following a comprehensive review of research over the 150-year history of mechanical ventilation, the recent European Multidisciplinary Scientific Consensus Meeting (EUROVEN) considered that only 20 studies relating ventilation (i.e. outside air supply rate per person) to human response were conclusive. From them, a small number of conclusions were drawn, and some very large gaps in our knowledge of this important area of research were identified. Taking these as the starting point, this paper formulates a strategy for evaluating IAQ effects on people.
This paper is based on the results of Subtask B of the HybVent Project. It presents a critical review of the literature and recent developments in analysis methods for natural and hybrid ventilation in buildings. Ideally, analytical methods aimed at modelling hybrid ventilation systems should incorporate at least three key aspects i.e: the natural ventilation mode, the mechanical ventilation mode and the control strategy. Depending on the input parameters used within the control strategy, thermal comfort and indoor air quality related parameters may also need to be predicted.
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