Two-Stage Evaporative Cooler for Mushroom-Growing Houses in Hot and Humid Climates

Shiitake ( Lentinula edodes ) is one of the most cultivated mushrooms in the world, and it prefers a temperate climate. The improvement of warm-weather shiitake strains is one way to increase shiitake yield in Thailand. Mushroom-growing houses should be equipped with mechanical cooling to control and establish the optimal environment for cultivation. In this study, an Indirect–Direct Evaporative Cooling (IDEC) system consisting of a cooling coil and evaporative cooling (cellulose pad) was tested for its suitability for shiitake cultivation from August 2020 to December 2020. Under optimal shading of, and growing conditions, the IDEC system maintained the air temperature (27–28°C) and relative humidity in the required ranges. The mushroom compost was almost completely brown after the 100-day test and ready for the next fruiting phase. When compared with the fan-pad system, regression analysis showed that the two systems exhibited similar performance and had similar equipment costs. However, the IDEC system had a lower air temperature at a lower relative humidity, and its efficiency was over 100%. This study demonstrated that the IDEC system can be applied to promote shiitake cultivation in hot and humid climates.