Wilmer Pasut

Chamber Bioaerosol Study: Outdoor Air and Human Occupants as Sources of Indoor Airborne Microbes

Human occupants are an important source of microbes in indoor environments. In this study, we used DNA sequencing of filter samples to assess the fungal and bacterial composition of air in an environmental chamber under different levels of occupancy, activity, and exposed or covered carpeting. In this office-like, mechanically ventilated environment, results showed a strong influence of outdoor-derived particles, with the indoor microbial composition tracking that of outdoor air for the 2-hour sampling periods. The number of occupants and their activity played a significant but smaller role influencing the composition of indoor bioaerosols. Human-associated taxa were observed but were not particularly abundant, except in the case of one fungus that appeared to be transported into the chamber on the clothing of a study participant. Overall, this study revealed a smaller signature of human body-associated taxa than had been expected based on recent studies of indoor microbiomes, suggesting that occupants may not exert a strong influence on bioaerosol microbial composition in a space that, like many offices, is well ventilated with air that is moderately filtered and moderately occupied.

Effect of a heated and cooled office chair on thermal comfort

A heated/cooled chair was evaluated for its effect on thermal sensation and comfort. Thirty college students participated in 150 1.75-h tests. Two heated/cooled chairs were placed in an environmental chamber resembling an office environment. The chamber temperatures were set at 16°C, 18°C, 25°C, and 29°C (60.8°F, 64.4°F, 77°F, 84.2°F). During the tests, subjects had full control of the chair surface temperature through a knob located on the desk. An additional 64 tests with 16 subjects were conducted at the same 4 temperatures but with regular mesh or cushion chairs in order to provide reference results for comparison. Subjective responses about thermal sensation, comfort, and temperature satisfaction were obtained at 20-min intervals and eight times before, during, and after a break period. The chairs energy consumption was monitored continuously. The results show that the heated/cooled chair strongly influences the subjects’ thermal sensation and comfort, providing thermal comfort under all tested conditions, both warm and cool. The average power draw is 27 W at 16°C (60.8°F), and 45.5 W at 29°C (84.2°F) ambient conditions.

Kpis For Building

List of Key Performance Indicators, , characterizing the different aspects of building and district performances selected based on existing building related databases (such as the Observatory of the EU Building Stock), literature research, or defined ex novo, in order to give a broader vision on the performances and their affecting parameters