Abstract: A data room air circulation system has adjacent racks located. The racks have a front, a rear, and a first and second side. A computer system component is mounted in at least one of the racks. A cold aisle, containing cold air, is located at the front of the racks. As the cold air passes through the component, hot air is formed and discharged to a hot aisle located at the rear of the racks. A baffle, having a front end, a rear end, and a hot air side is located between the racks. The front baffle end is attached to the front of one of the racks, and the rear end is attached to the rear of the other of the racks. The baffle separates the cold aisle from the hot aisle for at least the height of the baffle.