AIR CONTAMINANT DISTRIBUTIONS IN A COMMERCIAL LAYING HOUSE

ABSTRACT Total particle counts (TPC), carbon dioxide (CO2) levels, ammonia (NH3) levels, and room air temperature were monitored in a commercial cage laying house in Pennsylvania. The inlet and the exhaust were monitored for 24-h periods once a week from July 1989 to February 1990 while six other sampling locations in the house were monitored for 24-h periods once each six weeks. At each sampling location, air contaminant levels were measured at the alley and at each of the four cage decks. Results showed that more than 99% and 97% of total particles were smaller than 10.0 and 5.0 |im in diameter, respectively. TPC, CO2 levels, NH3 levels, and air temperature exhibited day-to-day variations but bird age effect was not significant. Mean daily TPC, CO2 levels, NH3 levels, and temperature ranged from 18 to 103 particles/mL, 553 to 4424 ppm, 9 to 54 ppm, and 17° to 30° C, respectively. Overall air quality was observed to be poorer at locations most distant from the exhaust fans. There were significant differences among locations in NH3 levels and temperature but there were no significant differences in TPCs and CO2 levels. Ventilation rate appeared to be the most important factor influencing indoor air quality. Mean TPCs were significantly higher while mean CO2 and NH3 levels were significantly lower in hot weather than in cold weather. CO2 levels and NH3 levels were highly correlated but there was little correlation between TPCs and the levels of CO2, NH3, or air temperature.