kW) heat the
station. Defrosting of the dome can be enhanced by enabling heating spirals
in the base of the dome (200 W) and an additional heated air-stream
(2 kW). The power required for heating and defrosting might seem
high, but is explained by the quite high thermal losses through the
thin plexi-glass dome and, also by the unpredictable weather in the
region, where a heavy snowfall might be followed by clear skies and
good observing conditions in less than one hour. The station is
protected from overheating by triple safety systems on the heating
devices as well as by a cooling fan.
All environment control devices (heaters, dome-heater, auxiliary heater, cooling-fan), as well as the illumination and electrical outlets used during service visits to the GLIP, can be remote-controlled via the housekeeping unit (Section A.4). If the housekeeping unit fails, the environment control settings fall back to safe hardware-defined values.
During the midnight sun period, the black surfaces visible through the
dome are exposed to intense sunlight and might reach high temperatures
(up to about
C has been measured.) As ALIS is not imaging
during this season, the domes are replaced with opaque covers during
summertime. This also keeps the need for cleaning the domes (and thus
the risk of scratches) to a bare minimum, by not exposing the
dome to bird-droppings and insects. For
summertime operations an air-conditioning device (cooler) is required
so as not to exceed the temperature specifications of the equipment
inside the dome.