THERMAL ENVIRONMENT AND STRESS OF WORKERS IN NATURALLY VENTILATED GREENHOUSES UNDER MILD CLIMATE

Wet-Bulb Globe Temperature (WBGT) is one of environmental heat stress indices.
To investigate the heat stress potential of greenhouse environment, WBGT was measured in a traditional twin-span naturally ventilated greenhouse in winter and summer, and a fifteen-span Venlo greenhouse with the floor area of 1.04 ha in winter in Japan.
The results showed that it was necessary to call workers’ attention to their health condition for midday hours even in winter and to keep them out of the greenhouse for midday hours in summer.
In these measurements, the WBGT data had high correlation with the inside air temperature.
It was considered that the heat stress potential of greenhouse environment could be estimated from the inside air temperature.
Additionally, the thermal environment and stress in the Venlo greenhouse in summer was estimated by using these WBGT data and the result of the wind tunnel model testing, together.
The local highest WBGT was estimated to reach to 39 °C while the outside air temperature and floor temperature in the greenhouse were 30 °C and 50 °C, respectively.

V International Symposium on Protected Cultivation in Mild Winter Climates: Current Trends for Suistainable Technologies

L. Okushima, S. Sase, I.-B. Lee, B.J. Bailey

wet-bulb globe temperature, traditional twin-span greenhouse, fifteen-span Venlo greenhouse, worker’s stress

https://doi.org/10.17660/ActaHortic.2001.559.118