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The effects of glycol on a closed loop system

Timco
Timco Member Posts: 3,040
in THE MAIN WALL
Without getting into the whole pro-press thing, how does one stop the "blue spots" from forming on systems with glycol? It seems to not be leaking, but there they are. Is there a vent capable of handling glycol better? How does it act in the HX compared to water? Is there a less corrosive alternative? Saline solution? Seems there have been a few comments against the stuff, but seems like putting up with some blue spots is cheaper than the frozen loops in the other thread...

Tim
Just a guy running some pipes.

Comments

  • Canuck_3
    Canuck_3 Member Posts: 39
    Well...

    it's more expensive, harder to pump and thermally, less efficient than plain water - plus it's messy when you have to open the system for service - but up here in The Great White North - if you even think it might freeze - put it in.
  • hot_rod
    hot_rod Member Posts: 23,392
    It's sneaky stuff

    and seems to "blue out" even the tightest of threaded joints. Not a lot of options. Stay a way from threaded joints, although even the ball valve assembly joints sometimes "blue."

    I did see a company manufacturing Corn Glycol, corn based instead of oil based. i'm not sure it would be less leak prone?

    Dow builds a product called Slytherm (sp). I've seen it used in some solar systems. Very expensive but doesn't seem to have the seep issues. I have 55 used gallons if you want to experiment :)

    We used glycerin in PVC fire sprinkler systems for years. It's very thick when cold and takes a gear pump to even shove it in a system if it is cold. Talk about a messy fluid to clean after a spill or leak!

    I've heard one solar company talk about trying glycerin for a solar fluid. It may work as the panel gets warm before the circ starts?

    hr
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • Timco
    Timco Member Posts: 3,040


    Forgive the question, but why not alcohol?

    Tim
    Just a guy running some pipes.
  • hot_rod
    hot_rod Member Posts: 23,392
    a bit flammable

    but the geo folks have used it for years.

    Our good friend larry has Vodka in his solar loop. if times get real tough.... :)

    hr
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • Drew_2
    Drew_2 Member Posts: 158
    Hydronic Antifreeze

    Reading the list of things that could be used as antifreeze in a hyronic heating system made me think of the things that need to be of concern when choosing an fluid. Here are a few.

    - Fluids that go BOOM when used around spark or flame.
    - Fluids that corrode or eat away the system components.
    - Fluids components that are not listed by the FDA as non-toxic.
    - Fluid viscosity
    - Fluid heat transfer

    Just some fluid for thought.



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