Abstract: The principles of an air "scrubber" to remove atmospheric ammonia inside broiler housing are presented. The "scrubber" is able to replace over ventilation in cold weather and, thus, to save the supplementay enrgy for keeping desired temperature. Ammonia in air circulaten in the house was adsorbed on its way passing through the filter containing phosphoric acid to form ammonium phosphate using as a fertilizer. General equations for determining filter capability and efficiency in adsorbing ammonia, the methods for estimating the filter ability of replacing over ventilation and the amount of supplemental energy saved, and some data for filter design were presented.