11 ms·

How is mildew and mold avoided in the pipeline and interior spaces being heated by steam?

by metadat 2y ago

darknavi 2y ago
Pretty sure the steam is ran through radiators and not just dumped directly into the air.
- lxgr 2y ago
  Part of it is definitely dumped directly into the air through an over-pressure valve on each radiator. At least that's been the case in all steam-heated NYC apartments I've ever visited or lived in. But what counteracts this is a loss in humidity caused by the heating of cold air from the radiator itself (cold air warmed up reduces relative humidity), and in my experience, this more than counteracts the little bit of steam hissing out of the radiator valve. As a side note, I've always wondered if the steam being vented that way is actually coming from the steam plant, or whether there's a heat exchanger somewhere in between that isolates a building's steam network from the distribution one (which is the case for liquid water heating, as far as I understand).
  - mindslight 2y ago
    nit: The valve is a thermostat that vents the air/steam in the radiator when it's not hot enough, letting new steam come in and replace it. This gets heat to the radiator quicker (over pure diffusion), and provides a mechanism of controlling its individual heat output. Of course, these valves are often broken.
    - lxgr 2y ago
      Interesting, that explains why it's going off so consistently and makes a lot more sense than just avoiding overpressurization. Thank you!
dangerlibrary 2y ago
Super heated water is a pretty effective disinfectant within the pipes. For interior spaces ventilation is a legitimate problem in non-forced-air systems. Historically, you open a window.
harrison_clarke 2y ago
if steam leaks out and gets trapped somewhere, presumably that's a breeding ground for mildew and mold inside the pipe, can much life survive? is there anything to eat in there? has anything evolved specifically to live in NYC steam pipes?
- deleted 2y ago
  [deleted]
tallanvor 2y ago
Mold doesn't grow well outside of around 60-80F (15-26C), and it needs food. Steam and hot water systems also use treated water to help reduce corrosion in pipes. That said, radiators themselves still do corrode and create nasty looking water even if it's generally sterile. You should be more worried about Legionella, but proper steam and hot water systems will stay above 140F (60C) as that temperature not only prevents the bacteria from multiplying but will kill 90% of them within 2 minutes.

How is mildew and mold avoided in the pipeline and interior spaces being heated by steam?

darknavi 2y ago

Pretty sure the steam is ran through radiators and not just dumped directly into the air.

lxgr 2y ago
Part of it is definitely dumped directly into the air through an over-pressure valve on each radiator. At least that's been the case in all steam-heated NYC apartments I've ever visited or lived in. But what counteracts this is a loss in humidity caused by the heating of cold air from the radiator itself (cold air warmed up reduces relative humidity), and in my experience, this more than counteracts the little bit of steam hissing out of the radiator valve. As a side note, I've always wondered if the steam being vented that way is actually coming from the steam plant, or whether there's a heat exchanger somewhere in between that isolates a building's steam network from the distribution one (which is the case for liquid water heating, as far as I understand).
- mindslight 2y ago
  nit: The valve is a thermostat that vents the air/steam in the radiator when it's not hot enough, letting new steam come in and replace it. This gets heat to the radiator quicker (over pure diffusion), and provides a mechanism of controlling its individual heat output. Of course, these valves are often broken.
  - lxgr 2y ago
    Interesting, that explains why it's going off so consistently and makes a lot more sense than just avoiding overpressurization. Thank you!

dangerlibrary 2y ago

Super heated water is a pretty effective disinfectant within the pipes. For interior spaces ventilation is a legitimate problem in non-forced-air systems. Historically, you open a window.

harrison_clarke 2y ago

if steam leaks out and gets trapped somewhere, presumably that's a breeding ground for mildew and mold inside the pipe, can much life survive? is there anything to eat in there? has anything evolved specifically to live in NYC steam pipes?

deleted 2y ago
[deleted]

tallanvor 2y ago

Mold doesn't grow well outside of around 60-80F (15-26C), and it needs food. Steam and hot water systems also use treated water to help reduce corrosion in pipes. That said, radiators themselves still do corrode and create nasty looking water even if it's generally sterile. You should be more worried about Legionella, but proper steam and hot water systems will stay above 140F (60C) as that temperature not only prevents the bacteria from multiplying but will kill 90% of them within 2 minutes.