This study explains the environments of the low cost windowless swine building during summer. The structure had a curved roof. The framework was consisted of steel pipes, and the walls were made of reflective film to reduce the construction cost. The wall had the ventilation layer with double fixed coverings for decreasing the heat load caused from the outside during summer. The ventilation layer had a thickness of 0.2m. The ventilation system was a positive pressure ventilation. The ventilating fan on the gable flew the outside air into the room. The outside air was distributed equally in the longitudinal section of the room by using the ventilation duct. Three kinds of ducts which have one, two or four openings on the cross section were tested in this experiments. The internal curtain was tested to keep the air flow distribution in a good condition. The room air was exhausted to the outside through the ventilation layer. The results from measurements were as follows;
1. The room temperature was about 1.5K to 1.9K higher than the outside air temperature in the summer night time and was about 1K higher than the outside air temperature in the day time. As the room temperature was changed together with the outside air temperature, the room temperature might not be affected directly by the solar radiation.
2. From the relationship between the number of air changes and the inside-outside air temperature difference, it was clarified that the number of air changes in the room, which was more than or equal to about 20 times/h was required to keep the inside-outside air temperature difference within 1K during summer day time.
3. By using with the ventilation ducts having one opening on the cross section, we got the two patterns of air flow distribution in the room having internal curtain or no curtain. These patterns showed the better air flow distribution than the other patterns obtained by using the ventilation duct having two or four openings. Among these patterns, the best pattern was obtained at the time when the air flew along the internal curtains, because the air flew to the pigs directly.
The mathematical model of predicting the room temperature was based on the following assumptions. For the soil floor had the largest heat capacity in the construction materials of the room, the heat transfer of the soil was treated as the unsteady state in the mathematical model. As the heat capacities of steel pipes and film were small, the heat transfer of these materials were treated as the steady state. From the assumptions, it clarified the following.
4. The wall that had the ventilation layer consisted of the double fixed covering could make the room temperature about 2.0K lower in the summer day times and about 0.2K higher in night than the temperature of the case having the single fixed covering wall.
5. In the summer day time, the heat transfer through the wall having the ventilation layer consisted of the double fixed covering was about 35% of the heat transfer through the single fixed covering wall of windowless swine pipe building.
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