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outdoor air

Moulds, bacteria and MVOC in classroom and outdoor air, and microbial components in settled dust from schools in Shanghai, China

Thirty classrooms in 10 schools in Shanghai, China, were investigated in winter. Dust wascollected by vacuum cleaning, analysed for ergosterol, muramic acid, and 3-hydroxy fattyacids (LPS) by tandem mass spectrometry (GC-MSMS). Airborne microoganisms weresampled on Nucleopore filters (CAMNEA). The compound 1-octen-3-ol was found in higherconcentrations in indoor than in outdoor air. Total indoor bacteria were positively correlatedto both LPS and muramic acid in settled dust. Indoor and outdoor air contained many viablespecies.

Contributions of outdoor, indoor and other sources to personal VOC exposure in five European cities

Exposure data from the EXPOLIS study was used to compare the contributions of indoor andoutdoor sources to personal exposure to selected VOCs (TVOC, benzene, xylenes,ethylbenzene, nonane, decane, undecane, alpha-pinene and 3-carene) in Athens, Basel,Helsinki, Oxford and Prague for non-ETS-exposed individuals. Indoor sources were found tobe the largest contributors to personal exposure to TVOC, terpenes and alkanes. Theircontribution was also important for aromatics, including benzene in Basel and Prague.Workplaces contributed only marginally to the median population exposures.

Indoor and outdoor nitrogen dioxide concentration in residential houses in Australia

As part of a larger indoor environmental study, residential indoor and outdoor levels ofnitrogen dioxide (NO2) were measured for 14 houses in a suburb of Brisbane, Queensland,Australia. Passive samplers were used for 48-h sampling periods during the winter of 1999.The average indoor and outdoor NO2 levels were 13.8 6.3 and 16.7 4.2 ppb, respectively.The indoor/outdoor NO2 concentration ratio ranged from 0.4 to 2.3, with a median value of0.82.

Distributions of indoor and outdoor air pollutants in downtown Rio de Janeiro city, Brazil

Indoor air quality (IAQ) has been a matter of public concern in Brazil. An IAQ survey wasconducted in an office building and in a commercial bank in Rio de Janeiro, Brazil. Indoorand outdoor air of offices was analysed due to the possibility of causing adverse effect on thehealth of the occupants. Measurements were made in a day during working hours. Sampleswere collected for volatile organic compounds (VOCs), total volatile organic compounds(TVOCs), aldehydes, total particulate matter (TPM) and microbiological analysis.

How do the indoor size distributions of airborne submicron and ultrafine particles in the absence of significant indoor sources depend on outdoor distributions ?

The inhabitants of Central Europe spend more of their time indoors. And indoor pollutants often affect human health more than the outdoor pollutants. This study aims at analysing how the indoor size distributions of submicron and ultrafine particles depends on outdoor distributions.
In the absence of indoor sources, concentrations of particulates are lower than in outdoor concentrations.

A field study of thermal comfort in outdoor and semi-outdoor environments in subtropical Sydney Australia

Many indoor models have been developed to describe thermal indoor discomfort, but are they relevant to outdoor or semi-outdoor environments ? They have not been yet critically validated . So, the thermal comfort of more than one thousand subjects living in outdoor and semi-outdoor locations in subtropical Sydney has been investigated by a questionnaire on the one hand and measured with micro-meteorological instruments.

Energy conservation benefits of a dedicated outdoor air system with parallell sensible cooling by ceiling radiant panels

Dedicated outdoor air systems (DOAS) integrated with ceiling radiant cooling panels as a parallel sensible cooling system are being considered as an alternative to conventional variable air volume (VAV) systems for commercial buildings because of their energy conservation, first and operating costs, and indoor air quality advantages. A pilot DOAS/radiant panel cooling system is being constructed on a university campus to investigate its advantages over alternative cooling systems in

Optimal design of all-air systems price sensitivity

This paper shows that it is possible to calculate the optimal outdoor air rate at different outdoor temperatures in the economiser cycle. The price of heat must increase 3 times before the optimal outdoor air rate during heating gets lower than during cooling. The optimal outdoor air rate during heating is determined primarily by the price of heat. The optimal outdoor air rate during cooling is determined primarily by the price of cooling capacity.

The effect of external conditions on indoor air quality in new buildings

The development of indoor air quality was studied in three newly finished buildings in Helsinki, Finland during the years 2000-2002. The concentration of volatile organic compounds (VOC), formaldehyde and ammonia, for which the Finnish Classification of Indoor Climate 2000 gives target values, in indoor air as well as the air exchange rate, relative humidity and temperature were determined for the newly finished buildings and 6- 12 months after the buildings had been taken in use.

The ABCs of DOAS (Dedicated Outdoor Air Systems)

Up to now, the use of a single HVAC unit to handle ventilation along with mechanical cooling was the aim of designers : it permitted to curb the cost of a building's mechanical system. In this article the author suggests a new design approach to treat the ventilation air and to manage the latent cooling load for the building. It consists in "splitting" the building's total cooling load with a DOAS. This approach allows each component of the HVAC system to do what it does best.