An evaluation of the ventilation performance using a new structure of plastic low tunnels

Plastic low tunnels (hereafter called tunnels) are used as thermal insulation during cold seasons.
Opening both sides of films from the bottom is a conventional ventilation method for tunnels to prevent high temperatures during daytime.
This is accompanied by a stoop and imposes a high workload on laborers.
We created a prototype of a new tunnel structure for reducing the workload of the ventilation system and evaluated its ventilation performance.
This prototype, namely, slide parts, could be attached to the conventional tunnel and moves horizontally by slide rails (one unit of slide parts has a length, width, and height of approximately 1, 0.95, and 0.6 m, respectively). At the same distance, the work time of the prototype for ventilation was shortened by approximately 76.7% compared with that of the conventional method.
To evaluate the ventilation performance, we measured and compared the temperatures under the prototype and conventional tunnel.
During daytime, the prototype tended to result in lower temperature than the conventional method, even though no temperature difference was observed between both methods during nighttime.
In the prototype, the films completely removed from the measuring point, but those of the conventional tunnel remained in the upper area.
Our results suggest that the newly developed tunnel had equal thermal insulation compared with the conventional tunnel during nighttime, and its ventilation performance was higher than that of the conventional tunnel during daytime with a low workload for ventilation.

IV Asian Horticultural Congress – AHC2023

Y. Yoneda, H. Kawashima

labor saving, plastic low tunnels, ventilation performance

https://doi.org/10.17660/ActaHortic.2024.1404.40