Using Passive Flux Samplers to determine the ammonia emission from mechanically ventilated animal houses

Abstract

Ammonia emissions from animal houses are an important environmental issue in theNetherlands. The current technique in the Netherlands to measure ammonia emissions inmechanically ventilated animal houses is the chemiluminescence method (using a NOx monitor afterconversion of NH3 to NO). During campaigns to measure emissions from animal houses, it becameclear that management is an important factor in determining the emission level. Differences betweenanimal houses of the same type and kind of animal may differ more than the variation in time andseason within one animal house. These management related differences in emission factors point atthe need to measure more animal houses during a shorter period. This stresses the need fordevelopment of flexible methods to be used in short term measurements, which allows monitoringthe ammonia emission from a larger number of animal buildings per year. In this paper, a practicalfarm with different housing systems and two types of ventilation shafts (with and without a lid in theventilation shaft to regulate the temperature inside the animal house) was selected to test the performance of passive flux samplers to measure the ammonia emission from mechanicallyventilated animal houses. A statistical t-test shows that the differences between passive fluxsamplers and the reference method are not significant at the 95% significance level when combiningall measurements. The use of a lid in the ventilation shaft improves the correlation between passiveflux samplers and the reference method. As a result of these measurements, passive flux samplersare presented as an alternative to measure the ammonia emission from mechanically ventilatedanimal houses.