Air leaves the poultry house and enters the manure drying tunnel, and then circulates through the manure, further aiding in drying the manure, and then the air exits the building. The roller sleeves, combined with the perforated manure belt, allow for thorough and even air circulation. The roller sleeves keep the manure belt from touching the rollers, keeping the manure away from the rollers, resulting in longer lasting rollers. The chopper consists of a rotating shaft which chops up the manure chunks before they are fully dried, allowing manure to be dried more evenly.