The ISS has an 28 tons active cooling system that barely radiates away as much heat as a one ton HVAC unit on Earth (70kW). It's hard to generate a temperature

The ISS has an 28 tons active cooling system that barely radiates away as much heat as a one ton HVAC unit on Earth (70kW). It's hard to generate a temperature gradient when you're blasted from the unfiltered Sun on one side, and reflected IR from Earth.