ABSTRACT Acomparison of drip cooling, zone cooling, and conventional ventilation was performed on lactating swine. Overall, the cooling systems did not significantly improve swine performance (i.e. sow weight loss, piglet survival, piglet weight gain, etc.). Based on this 2-year study and solely swine performance, neither drip cooling nor zone cooling systems should be installed in areas with climatic conditions similar to eastern South Dakota. However, the drip and zone systems highly significantly lowered sow respiration rates by 40 and 28%, respectively, when compared to the respiration rtaes of sows from a conventionally ventilated room. Older sows consumed 10% more feed than younger sows. Older sows returned to estrus after weaning approximately 2 days sooner than younger sows.