Indoor air quality and airflow distribution as a new factor in surgical operating theatres: a new hypothesis

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.

Experimental and numerical VOC concentration field analysis from flooring material in a ventilated room

The aim of this study is to analyse the impact of volatile organic compounds emissions from asolid flooring material on the concentration field in a ventilated room. A field study has beenconducted in the CSTB experimental house MARIA. Measurements were performed in a testroom recently equipped with a flooring material made of pine wood and under controlledventilation conditions. a-Pinene was selected as tracer from flooring VOC emissions. Velocityand temperature fields are measured in different points of the room.

Deflection ventilation - a conceptual introduction

This paper proposes a new mode of ventilation for indoor airflow. It uses a plate or a curvedvane to divert a jet of air directly into the breathing zone. Computational results show that withproperly selected diffuser locations and design air supply velocities, the proposed systemwould be able to maintain better thermal comfort with a smaller temperature differencebetween the head and foot level, and possibly lower energy consumption, when compared withconventional systems.

Influence of geometry of thermal manikins on concentration distribution and personal exposure

A number of different thermal manikins have been applied in literature to experimentallystudy the indoor environment. These manikins differ in size, shape and level of geometriccomplexity ranging from simple box or cylinder shaped thermal manikins to humanlikebreathing thermal manikins. None of the reported studies, however, deals with the influenceof geometry of the thermal manikin.

Ventilation and IAQ performance of a typical split-system air-conditioning unit in a residential apartment in singapore

Split system air-conditioning units are commonly employed in residential buildings inthe tropics due to their convenience in terms of energy conservation, aesthetics,flexibility, acoustic performance and ease of operation. This paper presents ourfindings from a recent study of the IAQ and ventilation characteristics in a masterbed-room of a condominium unit in Singapore, employed with a split system airconditioningunit. The attached bathroom is equipped with an exhaust fan, whoseoperation and its impact on the resulting IAQ and ventilation characteristics was alsostudied.

The impact of a personalized ventilation system on indoor air quality at different levels of room air temperature

The performance of a Personalized Ventilation (PV) system with regard to air qualityperceived by people was studied at three room temperature levels: 23, 26 and 29C. Thirtyhuman subjects participated in the experiment. The system supplied both isothermal (23, 26,29C) and non-isothermal (23C) outdoor air from an outlet attached to a moveable arm. Thesubjects were delegated with control of both airflow velocity and its direction. Physicalmeasurements performed with a breathing thermal manikin were used to explain the resultsfrom the human subject experiments.

Influence of geometry of thermal manikins on room airflow

A number of different thermal manikins have been applied in literature to experimentallystudy the indoor environment. These manikins differ in size, shape and level of geometriccomplexity ranging from simple box or cylinder shaped thermal manikins to humanlikebreathing thermal manikins. None of the reported studies, however, deals with the influenceof geometry of the thermal manikin.

Air change rates in multi-family residential buildings in northern Portugal

Existing technical recommendations and standards regarding natural ventilation in Portugalestablish one air change rate, ACH, in main rooms (bedrooms and living rooms) and fourACH in service rooms (kitchens and bathrooms).

A statistical approach to the evaluation of the maximum velocity within the occupied zone

Currently, a design of the maximum velocity stress in the occupied zone is based on applicationof the jet theory equations or on the data from the manufacturers catalogue. However, thesemethods are based on the idealized test conditions in empty rooms and do not necessarily predictthe conditions existing in realistic rooms with heat sources and sinks. Furthermore, little data isavailable of the distributions inside the occupied zone. A new statistical method for occupiedzone maximum velocity prediction is introduced and verified using experimental data.

The verifying concept for the cleanliness of HVAC systems

The visual evaluation method has been created for a primary method to verify cleanliness ofHVAC system. The results of two simple measuring methods for thickness of dust and debriswere compared to accumulation values measured by vacuum sampling method. The thicknessof dust layer and the dust accumulation results correlated when the dust was homogeneousbut the correlation was poor if the quality of the dust varied. Both the field and laboratorystudies showed that a commercial contact method gave lower microbial counts than the swabmethod with cultivation.

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