Etude du microclimat et de la ventilation d'une porcherie d'engraissement

Temperature, relative humidity and air speed were measured during 4 weeks in two compartments of a fattening pig house. Temperature was controlled by automatic regulation of the extractor fan. Average NH3 and CO2 concentrations over a 8-h period were measured 4 times in each compartment at 1-week intervals. In a compartment without pigs, ventilation rate was measured at 8 fan speeds and air speed was measured in 6 pens. Mean temperature was 24C and relative humidity 71%. despite large variations of outside temperature, 95% of the daily variations of inside temperature were <6C and 68% of the hourly variations were <0.5C. More than 90% of the daily variations of relative humidity were <20%. Thermal regulation with the fan was therefore effective. Mean NH3 concentration was higher than the usual recommendations, 26(vs 20) ppm and the CO2 concentration lower, 1688 (vs 3000) ppm. Measurements of ventilation rate showed that the air inlet area was too small for the maximum power of the fan. The ventilation rate was at most 3200 m/h for 78 pigs. Air speeds higher than 0.2 m/s were also measured 0.5 m above the floor in some of the 6 pens. These excessive values could be related to air inlet area.