Re:The Lost Art of Steam Heating (2017) [video]
by avhon1 on Tuesday November 13, 2018 @03:05PM
(#18444388)
> I've sometimes wondered if it would be practical to operate a steam heating system at a partial vacuum so that the condensation/vaporization could occur at a lower temperature
He actually talks about exactly this in the video! https://www.youtube.com/watch?v=TQB0KK2rxcw&t=573
"You'll be sending steam up into the building at temperatures, in some cases, as low as 150 degrees" (83 degrees C)
Re:The Lost Art of Steam Heating (2017) [video]
by userbinator on Tuesday November 13, 2018 @03:46PM
(#18444720)
Look up "vacuum vapor heating" for more info --- quite clever to do it even without using a vacuum pump, just special vent valves.
But the heat of vaporization is also huge: it takes about the same energy to boil a quantity of water as it does to take it from 0°C to 100°C.
The main downside is that the vaporization/condensation has to take place at 100°C, which is arguably a bit hotter than is ideal for safe space heating. Also the water returning to the boiler might not be cold enough to condense out the water vapor from the fuel (more important in fuels like natural gas with a big difference between HHV and LHV).
I've sometimes wondered if it would be practical to operate a steam heating system at a partial vacuum so that the condensation/vaporization could occur at a lower temperature, but I haven't seen that done anywhere so I'm guessing the answer is no.