The Advanced Technology Solar Telescope coude lab thermal environment

The ATST scientific instruments are located on benches installed on a large diameter rotating coude lab floor. The light path from the telescope to the instruments is greater than 38 meters and passed from external ambient conditions to the 'shirt-sleeve' environment of the coude lab. In order to minimize any contribution to local seeing or wavefront distortion, two strategies are implemented. First, an air curtain is installed where the beam passes from ambient conditions to the lab space and second, the coude lab environmental conditions are tightly controlled. This paper presents the design parameters of the environmental conditions, the basis of each design parameter, and overview of the equipment and components of the system planned to control those conditions, and the thermal and computational fluid dynamic analyses that have been performed in support of the system as designed.