AIVC - Air Infiltration and Ventilation Centre

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ventilation system

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.

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.

A study of demand-controlled ventilation (DCV) and constant air volume (CAV) systems

One of the most common measures of IAQ (indoor air quality) is carbon dioxide, CO2, generated by human respiration, in particular, where the main source of pollutions are occupants. In this report, the occupancy-related pollutants are considered as the main pollutant source. However, other type of sources may also be removed satisfactory when governing the ventilation system for removal of

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.

Statistical analysis of parameters influencing the relationship between outdoor and indoor air quality

Within the framework of the French national research program PRIMEQUAL, measurementsof outdoor and indoor pollution have been carried out in eight schools of La Rochelle (France)and its suburbs. The buildings were naturally ventilated by opening the windows ormechanically ventilated, and showed various air permeabilities. Ozone, nitrogen oxides (NOand NO2), and particles (15 size intervals ranging from 0.3 to 15 m) concentrations werecontinuously monitored indoors and outdoors for two 2-week periods.

A questionnaire survey of special old age nursing homes and elderly health care facilities in Japan

We studies the conditions in special old age nursing homes and elderly health care facilities in Japanespecially in a region with a cold climate. A questionnaire survey for all special old age nursing homes and elderly health care facilities in Sapporo and Fukuoka City, and Hokkaido, Saitama, Kanagawa, and Osaka Prefecture, and Tokyo Metropolis was performed. The main questionnaire asks about heating, air-cooling, ventilation systems, sanitary systems and indoor air quality including bio-aerosol and odours.

Microbial contamination of indoor air due to leakages from crawl space - a field study

The aim of that study was to find out if a potential air flow from crawl space has an influence on the indoor air quality : is there a potential risk for the first floor apartments ? A balanced ventilation system is recommended.

Study of the effects of essential oils on microbes present in ventilation systems

Many studies have shown that ventilation systems often host bacteria and fungi that may bedangerous for the health of people exposed to them. This problem may be particularly acute inhospitals, where exposed people are more sensitive. The paper presents the methodologydeveloped to study the effectiveness of some plants extract, the essential oils to hindermicrobial growth, in order to propose an indoor air purification method based on thegermicidal and odorant properties of the essential oils. First results are encouraging.