Carrier Context :
Unique Projects

  La Silla: a finer view of the heavens

The Atacama may be known for intense sunlight during the day, but radiational cooling at night quickly lowers the outside temperature even in the summer. That's why anyone walking around inside the actual telescope dome is usually wearing a jacket.

The cooling system is designed for the telescope, not for the astronomers," Silva quips. "Of course, all the astronomers work in control rooms outside the dome, so the low temperature doesn't really matter. The control rooms are air conditioned by Carrier, too, so the astronomers have the best of both worlds."

Using historical weather data, the dome's daytime interior temperature is based on projections of what the exterior temperature will be that night. When the dome is opened, Silva says, there is rarely more than a degree or two of temperature difference. That wasn't as easy as it would seem since the distance from the dome's floor to the ceiling is an uninterrupted 15 meters. The temperature difference between floor and ceiling used to be seven degrees Celsius. To reduce temperature stratification, Silva's design discharges some cool air directly under the telescope's 3.6-meter-wide mirror at floor level; the rest of it flows up through snake-like insulated ducts toward the dome's ceiling.

( top of page | continued)