The objective of this study was to develop an electric air-cleaning system for animal houses to control noxious gases and odors. An AC-powered ferroelectric packed-bed plasma reactor was tested for its ability to decompose ammonia and odors in the air. Four important parameters that affect reactor performance were investigated: gas residence time in the reactor (four test levels, 0.2 to 1.3 s), power voltage (six levels, 0 to 15 kV), power frequency (two levels, 60-Hz and 18-kHz), and initial ammonia concentration (three levels, 21, 27 and 55 ppm). Up to 95% ammonia decomposition efficiencies were obtained under a combination of test conditions. The packed-bed plasma reactor was effective in decomposing odors in the air taken from a swine house.