indoor air quality

These Guidelines recommend the ventilation required to obtain a desired indoor air quality in a space. The first step is to decide the air quality aimed for in the ventilated space. A certain air quality is prescribed to avoid adverse health effects while a decision is required on the level of perceived air quality aimed for in the ventilated space. Three different comfort levels are suggested. The next step is to determine the pollution load on the air caused by pollution sources in the space.

The report contains a summary discussion of human health effects linked to indoor air pollution (IAP) in homes and other non-industrial indoor environments. Rather than discussing the health effects of the main different pollutants which can be found in indoor air, the approach has been to group broad categories of adverse health effects in separate chapters, and describe the relevant indoor exposures which may give rise to these health effects.

The report summarizes information on indoor pollution by formaldehyde (HCHO) in European countries participating in the concerted action "Indoor Air Quality and Its Impact on Man" (COST project 613). Major scope of the report is to give concise information to people involved in research planning, policy making and regulatory activities and to identify a European view of the issue. The summary includes a short review of health effects of formaldehyde, of existing air quality guidelines and standards and of indoor sources of formaldehyde.

The report summarizes information on indoor pollution by nitrogen dioxide (NO2) In European countries participating in the concerted action "Indoor Air Quality and Its Impact on Man" (COST project 61 3). Major scope of the report IS to give concise information to people involved In research planning, policy making and regulatory activities and to help to identify a European view of the issue. The summary includes a short review of health effects of NO2 and of existing air quality guidelines and standards.

Thermal comfort and indoor air quality (IAQ) play a vital role in creating a pleasant and healthier indoor environment for occupants. The supply air conditions and the concentration of CO2 contaminant present in the supply air can decide the comfort level and purity of air in indoor environments. In this study, an effort was made to investigate the combined effect of a chilled ceiling and displacement ventilation (CC-DV) air conditioning (A/C) system that would possibly achieve good thermal comfort and IAQ in a proposed office building subjected to hot and humid climatic conditions.

The performance of stratum ventilation, a recently developed ventilation strategy, is assessed in terms of thermal comfort and indoor air quality using experimental and computational fluid dynamics (CFD) techniques. The case of a typical Hong Kong workshop under local thermal boundary conditions is used to examine the ventilation system. Various factors including percentage dissatisfied (PD) and mean air age/CO2 were computed to determine the system performance. The stratum ventilation is shown to produce improved indoor air quality and thermal comfort for this particular case study.

Aerosol detection in HVAC duct components is a critical component of contaminant detection and analysis. Incorrect placement of a sensor inlet within the ductwork can have a significant, deleterious effect on capture efficiency and sample accuracy. Computational fluid dynamics studies were conducted of straight rectangular cross-section ductwork and a 90° bend to determine flow patterns and simulations of particulate injections were made at various locations across the inlet. The resultant particle distributions were analyzed to determine the optimal placement for a sensor inlet.

Hybrid ventilation represents an interesting option both to guarantee good air quality for indoor environments and to reduce the energy consumption related to the mechanical motivation of the air.

Stratum ventilation is a recently proposed air distribution system. It works by creating a layer of fresher air in the occupants' breathing zone. This is achieved by placing large supply inlets along the side-walls of the room just above the height of the occupants. Fresh air is emitted into the room and gradually loses momentum. The supply velocity is sufficiently strong to provide fresh air directly to the occupants without space mixing.

Ventilation systems are primarily designed for ensuring good indoor air quality (IAQ). However, building energy requirements tend to put demand on reducing air change rates. The assessment of the performance of ventilation systems over long periods has thus become a subject of importance. In this framework, five ventilation systems were investigated for a heating period in a single-family house using a representative occupancy and pollution schedule. This was undertaken using SIMBAD, a combined mass and heat transfer toolbox. This paper compares the different results.