Performance of ductless personalized ventilation in conjunction with displacement ventilation: Physical environment and human response

Local thermal sensation modeling-a review on the necessity and availability of local clothing properties and local metabolic heat production

“…The impact of these findings on local heating and cooling research can be seen from two perspectives: 1) considering the normal fluctuations in LTS votes and 2) considering the statistical significance between two sensation votes. For the first point of view, studies show that LTS votes within a group of subjects vary between 2 steps on the sensation scale . This finding would be in line with the presented variation of thermal sensation for most body parts, excluding upper arm and foot.…”

A review of human thermal comfort in the built environment

“…Results of the personalized conditioning systems with regard to thermal comfort were equal or better than conventional cooling systems [122][123][124][125][126][128][129][130][131][132]. The use of floor fans [133] and the chair equipped with fans [136] were able to maintain acceptable thermal comfort conditions with air temperatures up to 30ºC; the use of electric fans (China) could provide a comfortable environment at 28°C to 32°C [135].…”

“…Other studies in climatic chambers, involving an individually/personally controlled system were performed in Denmark (with mechanisms for facial ventilation and heating [123] and ventilation, heating and cooling [124], radiant and convective cooling [125] and another system using a ductless personalized ventilation in conjunction with displacement ventilation [126]), in Hong Kong (chair-based personalized ventilation -PV-system) [127], in Lebanon (low-mixing ceiling-mounted personalized ventilator system) [128], in Hungary (a novel PV system with air flow coming alternatively from three different directions) [129,130], in the United States (heated/cooled chair [131], ceiling fans [132] and floor fans [133]), in South Korea (floor-standing room airconditioner) [134], in China (electric fans were placed in front of subjects, directed at their faces) [135] and in Japan (chair equipped with fans) [136]. Results of the personalized conditioning systems with regard to thermal comfort were equal or better than conventional cooling systems [122][123][124][125][126][128][129][130][131][132].…”

Thermal environment and air quality in office with personalized ventilation combined with chilled ceiling

“…Personalized evaporative cooler is installed at workstations and explores the idea of "ductless" personalized ventilation [23,24]: air is drawn from the floor level and supplied toward occupant's face and upper body parts. Difference compared to "ductless" personalized ventilation is that air passes through saturated water sponge in the cooler and is cooled by 3e4 K. This combined system is proposed for hot and dry climate, where problematic are peak loads resulting in oversized HVAC systems.…”