Pipe Radiator
From Unofficial Stationeers Wiki
Pipe Radiators do not appear to absorb any thermal energy from the "sun." Placed on isolated pipe segments facing, separately, all four cardinal direction, despite the "sun" shining directly on a radiator, the pipe network temperature continued to fall at the same rate as a shaded radiator. Enclosed in a glass corridor, the trapped atmosphere absorbed more "thermal radiation" then the pipe radiators.