One of the two air distribution systems serving the office rooms of a 25-year-old large office building was balanced in autumn 2002. The supply and extract air flow rates of 173 office rooms were measured before and after balancing. Before balancing, the air flow rates varied considerably from room to room and many of the office rooms were over pressurised. The average extract air flow rate in the whole of the building was 20.7 L/s.person and the standard deviation 11.0 L/s.person. The aim of the balancing process was to meet the design values dating from 1978.
The paper examines the efficiency of a local exhaust applied during an orthopaedic surgicaloperation. During operations performing hip replacements bone cement is sometimes applied to fasten the new metal hip to the existing thighbone, especially in case of elderly patients. The bone cement emits harmful VOCs that may influence the operating room personnel and the patient. A local exhaust is applied to reduce the VOC concentration in the operating room air, however, apparently without success.
The paper deals with research on capture efficiency of reinforced exhaust system equipped withhorizontal slot exhaust hood, capture efficiency of which is increased by radial flow of supply air through a slot in hood flange. Investigation was carried out with the use of tracer gas method applied in order to measure the capture efficiency of the system, interferometric method in order to visualize tracer gas propagation from different sources, and smoke method in order to make flow patterns at exhaust system visible.
This paper provides an overview of existing guidance, regulations, and design approaches to control diesel exhaust from locomotives operating in buildings. First, design guidance and standards for exposure to major components of diesel exhaust are reviewed. Next, issues regarding engine design, fuel composition, and outdoor emissions control strategies and their potential impact on current and future indoor emissions are discussed. Ventilation approaches that have been implemented in existing facilities are also presented.
This article focuses on the replacement air component for atrium smoke exhaust, including comparisons of three design approaches. The concepts are illustrated by case studies.
There is an increasing evidence of air related sickness among infants and housewives in urbanIndia due to the use of liquefied petroleum gas. An attempt has been made in this study, tomonitor kitchens of 13 houses in the city of Jaipur for possible residential indoor air pollution(IAP), i.e. carbon monoxide (CO), sulfur dioxide (SO2), nitrogen dioxide (NO2) and respirablesuspended particulate matter generated during cooking. The role of the exhaust fan as aninexpensive means to dissipate these gases of combustion has also been studied.
A wind tunnel dispersion modeling study was conducted to investigate exhaust contamination of hidden versus visible air intakes. A hidden intake is typically on a building sidewall or on the sidewall of a roof obstruction opposite the exhaust source. A visible intake is at roof level or on top of
an obstruction, directly above the hidden intake. Overall, the study has shown what designers suspected: placing air intakes on building sidewalls is beneficial when the stacks are on the
Major sanitory problems occuring at industrial workplaces are induced by air contaminants. They represent a high financial cost. This paper sums up the main steps and results of the European Research project COST that has developed and optimized a system specifically geared to the local capture of contaminants : the REinforced EXhaust System (REEXS)
This paper presents the study of a local exhaust ventilation system with plain (unflanged) and flanged hoods. Centerline velocity and velocity contours in front of exhaust hood openingswere measured and compared to other previously reported results. Centerline velocity correlations are derived for a full range of hood axes. The effect of turbulence intensity and surrounding equipment on the velocity contours is also analyzed. Capture velocity for three different types of contaminant particles (saw dust, wheat flour, and sand) was determined.
The conventional constant air volume exhaust fan system is actually a variable air volume system. The fan airflow increases as the fume hood airflow decreases. Under partial fume hood exhaust airflow, the fan power is higher than the design fan power. Two energy efficiency measures are developed in this study to reduce the fan power of the conventional constant air volume exhaust system. In the first measure, a modulation damper is added in the main exhaust air duct and
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