Evaluation of Integral Effect of Thermal Comfort, Air Quality and Draught Risk for Desks Equipped with Personalized Ventilation Systems

This work evaluates the integral effect of thermal comfort (TC), indoor air quality (IAQ) and Draught Risk (DR) for desks with four personalized ventilation (PV) systems. The numerical study, for winter and summer thermal conditions, considers a virtual chamber, a desk, four different PV systems, four seats and four virtual manikins. Two different PV configurations, two upper and two lower air terminal devices (ATD) with different distance between them are considered. In this study a coupling of numerical methodology, using one differential and two integral models, is used. The heating, ventilating and air conditioning (HVAC) system performance in this work is evaluated using DR and room air removal effectiveness (epsilon(DR)) that is incorporated in an Air Distribution Index (ADI). This new index, named the Air Distribution Turbulence Index (ADTI), is used to consider simultaneously the TC, the IAQ, the DR and the effectiveness for heat removal (epsilon(TC)), contaminant removal (epsilon(AQ)) and room air removal (epsilon(DR)). The results show that the ADI and ADTI, are generally higher for Case II than for Case I, increase when the inlet air velocity increases, are higher when the exit air is located at a height 1.2 m than when is located at 1.8 m, and are higher for summer conditions than for winter conditions. However, the values are higher for the ADI than ADTI.

Automated summary

This study evaluated the combined effect of thermal comfort, indoor air quality, and draught risk on desks with four personalized ventilation systems. The results showed that in summer conditions, the Air Distribution Index (ADI) and the Air Distribution Turbulence Index (ADTI) were generally higher compared to winter conditions, increasing with inlet air velocity and being higher when the exit air was located at 1.2 m compared to 1.8 m, with ADI values being higher than ADTI.