I spent a winter in Moscow many moons ago, they had 2 sets of windows creating with a significant corridor in between them. Where I was, heating was centrally c

I spent a winter in Moscow many moons ago, they had 2 sets of windows creating with a significant corridor in between them. Where I was, heating was centrally controlled by the city so if it got hot, open the first window. Still hot? Open the second for extra fresh air. Quite a good system I thought and awfully romantic for me: watching the snow fall through open windows with the heating on full blast.