Large Environmental Chamber: Ammonia Recovery Calibration

The ability to accurately measure ammonia emissions from farms is an important issue both in terms of establishingemissions regulations and for effective evaluation of mitigation techniques. To address this issue, experimental trials werecarried out to determine the ability to quantitatively recover ammonia released within a large environmental chamberdesigned to house six dairy cows or manure processing technologies. Ammonia was released over 30 min periods at a rangeof values (0.1 to 0.7 g/min) from three positions within the chamber. Chamber temperature was maintained at 22.2
C. Air flowwas maintained at one of three setpoints; 10.5, 14.0, or 21.0 air exchanges per h. The amount of ammonia recovered fromeach release was determined by calculating the average increase in ammonia concentration during the release andstabilization periods, and multiplying by the measured volumetric air flow. Over 86 trials, the recoveries averaged 105.1 0.8% of the amounts released as determined by the weight change of the release cylinder. Small increases in measuredrecoveries were associated with increased air flow and increased amounts of ammonia released. Results from this studyindicate that increases in ammonia within the chamber, including shortterm increases, can be quantitatively recovered.