[andsoitis]

Presumably you also need a system to produce light indoors at night. You might as well have a single solution for both day- and night-time that uses renewable energy.

[gpderetta]

This is a nuclear bunker. Electricity might not be available or scarce.

[inetknght]

By the time external electricity is not available (assuming it was ever brought in, in the first place), you probably want to lose track of time.

[gpderetta]

Oh yes, also natural light itself might be scarce.

[iancmceachern]

I bet the air filtration system runs on electricity, they probably have a backup generator that lasts X number of days. After that you won't have clean air so light won't be an issue either.

[m4rtink]

The bigger cold war era civil defense bunkers around here (Czech Republic) usually have the following design for ventilation: * one or two filtration rooms, powered by electricity with optional manual backup * one or two diesel generators to provide electricity for the filtration system, lighting and other equipment * high pressure oxygen bottles for couple hours of total isolation - intended for the first few hours after a nuclear detonation when the regular filtration equpment could be overwhelmed by short halflife fallout and smoke/lack of oxygen due to the firestorm of the city arround burning

Examples of such shelters: - general purpose shleter Denis (capacity op to 2000 people): https://podzemibrno.cz/en/places-underground/cover-denis-und... - army headquarters shelter in the Vypustek cave (capacity 100+ people): https://vypustek.caves.cz/en - 10-Z shelter, Brno area civil defense headquarters (capacity 100+ people): https://10-z.cz/en/

Smaller shelters that could be found under many 50s era building were much more rudimentary, usually without idepedent source of electricity and just simple hand cranked filtration system.

[amelius]

Sounds to me it is closer to a student housing project that happens to be in a bunker.