@neauoire One word of caution 🚧 : I've heard of tubes freezing and breaking if they're exposed to clear night sky -- but this event occurred with vacuum tubes with interior metal tubes filled with water. The research group at UC Merced had to cover their vacuum tube + reflector experiment at night due to hazardous radiative cooling.
@clh3 ours are different, we use the household type that is normally installed on rooftops.