Heat exchangers extract heat from an air stream and deliver the heat to another airstream. The heat exchangers are modified with a filtration system to allow the heat exchanger to effectively run within the poultry house environment. The poultry house is retrofitted with at least four flat-plate cross-flow heat exchangers. The heat exchangers operate to meet at least the minimum ventilation rates for the young birds. As birds grow, heat exchangers operate in conjunction with building exhaust fans for ventilation needs. Multiple heat exchangers are located throughout the house to provide appropriate ventilation.