Animal Air Quality Research Facility
The Animal Air Quality Research Facility was constructed specifically for the purpose of studying air quality issues related to animal production, including the impact of animal diets on gaseous emissions.
The laboratory consists of 12 animal rooms, each 7’ w x 13’ l x 8.5’ h with interchangeable penning and watering systems. Penning, feed and water handling systems, and manure handling apparatus for each species is removable from the chambers in order to accommodate the needs of different species. Each room can accommodate one horse, one lactating cow, two growing heifers, six finishing pigs, 20 turkeys, 60 broiler chickens, or 80 laying hens. Manure volumes generated can be measured and collected from the animal room. Manure collection pans (10’ x 5’) roll under swine pens and can be removed as needed for weighing, sampling, and cleaning. These same pans serve as the flooring for the broiler chicken or turkey floor pens. Fecal/manure pans can be placed behind tie stalls when dairy cows are present, and emptied daily. Feed intake by the animals is measured daily. Laying hen cages house 10 hens each with eight cages per room in a two-tiered configuration.
The facility has continuous online monitoring capabilities for hydrogen sulfide, sulfur dioxide, ammonia, nitrogen oxides, methane, carbon dioxide, non-methane total hydrocarbons and oxygen. Through software control (LabVIEW Ver. 8.3, National Instruments; Austin, TX), gaseous concentration monitoring of the rooms occurs in sequential fashion, beginning first with incoming air for 15 min, then through each of the eight rooms’ exhaust airs for 15 min. The incoming air line is allowed to purge for 14.5 min and chamber sample lines are allowed to purge for 9.5 min before the start of data collection. Following purging, data was collected for 5.5 min. All gases are measured simultaneously within a sample stream. Samples from the chambers were pulled to a sampling manifold using a Cole-Parmer vacuum pump (Cole-Parmer Instrument Company, Vernon Hills, IL) at a rate of 30 L/min, through Teflon tubing (30.43 m long with an outer diameter of 0.95 cm) placed 12.7 cm into the exhaust duct of each individual chamber. From the manifold the air stream was diverted into four gas analyzers: a TEI 17C NH3 Analyzer (Thermo Electron Corporation; Franklin, MA) that determine NO, NO2, and NH3 concentration, a TEI 45C with a 340 converter (Thermo Electron Corporation; Franklin, MA) measuring H2S and SO2 concentrations, an Innova photoacoustic analyzer (California Analytical Instruments) to measure CO2, methane, non-methane total hydrocarbons, ammonia and nitrous oxide, and a BINOS 200M analyzer for measuring O2 and CO2 (Rosemont Analytical). Gas concentrations were recorded every 30 sec during the last 5.5 min of sampling in each chamber. The recorded values are exported to a spreadsheet, adjusted to standard temperature and pressure, and averaged. All averaged incoming air gas concentrations are subtracted from the chamber gas concentrations before chamber averages are calculated. Averages were calculated to determine the emissions between sampling times for a specific chamber.
Airflow rates into each room are continuously measured using orifice plates and a differential pressure transducer (Setra Model 239, Boxborough, MA) to measure the pressure drop across a 15.24-cm orifice plate in the incoming ductwork of each chamber. Using calibration curves, airflow estimates are determined and automatically recorded every 30 sec. Emission rate is calculated based on the airflow average and the gas concentration averages at standard temperature and pressure during the recorded sampling time.
Each room is individually heated and cooled, using 100 percent outside air and exhausting all of the air to the outside (no recycling). The temperature of each room is programmed, independently, and dictates the airflow rate in the room. Temperature and humidity of each room, measured using a CS500 Temperature and Relative Humidity Probe (Campbell Scientific, Inc.; Logan, UT), are continuously monitored and recorded (< every two seconds). The recorded values are exported to a spreadsheet, adjusted to standard temperature and pressure, and averaged. In the event that the temperature falls outside of the specified range, an alarm system places a series of phone calls to alert laboratory personnel. Software control will provide remote monitoring of chamber conditions at all times.