- #1
JeffOCA
- 49
- 0
Hi,
In astronomical observatories, the cupolas and their building walls are painted in white in order to reflect sunlight and not absorb too much warmth during the day. This minimizes the difference between internal and external difference when night falls.
However, in some observatories there are aeration gaps above the cupola. What for ?
If the cupola and its interior are heated by daylight, the gaps are useful to requilibrate the int. and ext. temperature at the beginng of the night.
But, during the day, these gaps are not efficient : warmed air from the outside enters the cupola where the air is colder.
Am I wrong ?
Other point : in some observatories the cupolas are green instead of white. Why ? Is it due to an oxydation of Cu ?
Thanks for answering.
JF
In astronomical observatories, the cupolas and their building walls are painted in white in order to reflect sunlight and not absorb too much warmth during the day. This minimizes the difference between internal and external difference when night falls.
However, in some observatories there are aeration gaps above the cupola. What for ?
If the cupola and its interior are heated by daylight, the gaps are useful to requilibrate the int. and ext. temperature at the beginng of the night.
But, during the day, these gaps are not efficient : warmed air from the outside enters the cupola where the air is colder.
Am I wrong ?
Other point : in some observatories the cupolas are green instead of white. Why ? Is it due to an oxydation of Cu ?
Thanks for answering.
JF