Indoor air quality investigation before and after relocation to WELL-certified office buildings

Air pollutant exposure in workplace environments has been associated with health and cognitive outcomes of workers. While green building certification programs have been instrumental in promoting indoor air quality (IAQ), the present literature indicates inconsistent evidence. Recent emergence and proliferation of WELL certification program that prioritizes human health has evoked new questions about its effectiveness in relation to IAQ. To investigate the effectiveness of the WELL certification, we have quantitatively compared IAQ results before and after relocation to two WELL-certified office buildings using the same cohort of occupants. Physical measures included integrated samples of TVOC, individual VOC, formaldehyde and acetaldehyde, NO2, SO2, O3 and longitudinal records of CO2 and size-resolved particles. Complementary survey responses about satisfaction with IAQ and thermal comfort were collected from ~250 employees. For the majority of air pollutants, there was no significant concentration difference between non-WELL and WELL buildings, but not always. The WELL-certified buildings had substantially higher levels of TVOC and individual VOC associated with paints, especially shortly after the relocation. However, there was statistically significant improvement in IAQ satisfaction after relocation into WELL buildings regardless of the air pollution levels, possibly confounded by thermal environment, awareness of the WELL certification or other non-measurable factors

HUMAN CONVECTIVE BOUNDARY LAYER AND ITS IMPACT ON PERSONAL EXPOSURE

Ph.DNUS-DTU JOINT PH.D

Transport of gaseous pollutants by convective boundary layer around a human body

<div><p>This study investigates the ability of the human convective boundary layer to transport pollution in a quiescent indoor environment. The impact of the source location in the vicinity of a human body is examined in relation to pollution distribution in the breathing zone and the thickness of the pollution boundary layer. The study, in addition, evaluates the effects of the room air temperature, table positioning, and seated body inclination. The human body is represented by a thermal manikin that has a body shape, size, and surface temperature that resemble those of a real person. The results show that the source location has a considerable influence on the breathing zone pollution concentrations and on the thickness of the pollution boundary layer. The highest breathing zone concentrations are achieved when the pollution is located at the chest, while there is negligible exposure for the pollution emitted at the upper back or behind the chair. The results also indicate that a decrease in personal exposure to pollutants released from or around the human body increases the extent to which the pollution spreads to the surroundings. Reducing the room air temperature or backward body inclination intensifies the transport of the pollution to the breathing zone and increases personal exposure. The front edge of a table positioned at zero distance from the human body can reduce the pollution transport to the breathing zone, or it can increase transport of the clean air from beneath if positioned at a 10-cm (0.33-ft) distance.</p></div

Human convective boundary layer and its interaction with room ventilation flow

10.1111/ina.12120Indoor Air25121-3

Occupant health & well-being in green buildings: Trends and Future Directions

Expectations for high performance green buildings have been evolving over the last four decades. Green certification systems define, recognize, and demonstrate leadership in addressing building problems related to people and the environment. These systems are premised on a theory of change where making the distribution in building performance visible provides opportunities for competitive differentiation that motivates and rewards action to create better spaces, buildings, and places. To date, there are more than 200 different green building certification programs around the globe, with estimates of at least 1 million certified projects