The commissioning experience of the facility for SALT is compared to the results of the analysis done during the design. A false steel floor incorporating forced ventilation that extends around the telescope azimuth pier is installed to prevent heat radiating from the concrete surfaces on nights when the ambient temperature drops to below room temperature. An infrared scan was done on this floor to verify that no heat is radiated into the telescope chamber from either the concrete or the warmer rooms underneath. The SALT site is windy all year round, and in order to utilize this natural resource and get better ventilation, adjustable louvers are used for natural ventilation. The control system automatically adjusts the louver openings depending on the wind speed and relative direction of the dome opening to achieve enough air changes during wind still nights. The louvers are throttled to limit windshake on the structure on windy nights. Results of the computational fluid dynamic analysis (CFD) and actual measurements are presented showing adequate temperature distribution at low wind speeds. The correlation between the CFD and actual measurements are discussed, with reference to the surface and air temperatures in the telescope chamber under different ambient conditions. The telescope chamber and dome are built out of insulation panels to limit energy losses during the day when the chamber is air conditioned. It also ensures thermal inertia of the building is low and consequently allows its temperature to react quickly to changes in external ambient temperature. The correlation between the expected and actual capacity of the air conditioners are also discussed.

Date Published: 29 September 2004
PDF: 11 pages
Proc. SPIE 5495, Astronomical Structures and Mechanisms Technology, (29 September 2004); doi: 10.1117/12.551471

Published in SPIE Proceedings Vol. 5495:
Astronomical Structures and Mechanisms Technology
Joseph Antebi; Dietrich Lemke, Editor(s)