Development of an Air-Recirculated Ventilation System for a Piglet House, Part 2: Determination of the Optimal Module Combination Using the Numerical Model

As the pig industry develops rapidly, various problems are increasing both inside and outside pig houses. In particular, in the case of pig houses, it is difficult to solve the main problems even if automation and mechanization are applied with Information and Communications Technologies (ICT). The air recirculation technology can be applied as a technology that can solve these typical problems in the pig industry, such as growth environment, livestock disease, odor emission, energy cost, and pig productivity. The air recirculated ventilation system (ARVS) can minimize the inflow of air from the outdoors and recycle the internal thermal energy of the pig house. The ARVS consists of (1) an air scrubber module, (2) an external air mixing module, (3) a UV cleaning module, (4) a solar heat module, and (5) an air distribution module. In this study, the growth environment of piglets was predicted using a numerical model when the ARVS was applied. Since the concept of air recirculation was used, numerous equations for predicting the internal environment should be iteratively calculated. Furthermore, it was necessary to determine the optimum condition of the modules by applying various boundary conditions. Therefore, the model was designed for numerical analysis based on the balance equations of environmental factors inside the piglet room. For each module, the module coefficient and equations were considered based on the previous studies. The analysis was conducted according to the system diagram of each module, and the growth environment inside the piglet room was evaluated according to the various environmental conditions. As a result of calculating the numerical model, the ventilation rate of 40 CMM or more was advantageous to properly maintaining the gas environment. In the summer season, it was necessary to additionally use the cooling device and dehumidifier. In the winter season, when using a heat exchanger and solar module, was more advantageous for maintaining air temperature inside the piglet room.