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Methanol in hydronic system?

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GW
GW Member Posts: 4,701
I’m not much of an anti-freeze expert, I try my best to stay away from the stuff.Glycol seems to be the most basic necessary evil.

I know methanol is preferred for geothermal systems, has anyone ever used it for residential hydronic, in the house?

I need to order some for a Geothermal customer, but I have another job with an attic air handler.

Thanks, Gary
Gary Wilson
Wilson Services, Inc
Northampton, MA
gary@wilsonph.com

Comments

  • mattmia2
    mattmia2 Member Posts: 9,747
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    Methanol is very corrosive, there are few resilient sealing materials that will stand up to it.
  • Zman
    Zman Member Posts: 7,573
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    I don't have any first hand experience with the stuff.
    You absolutely should not put it in a heating system that is tied to domestic water, even with a backflow device. It is poisonous.
    The flammability part would be a deal killer for me as well.
    http://www.geojerry.com/earthloopantifreeze.html
    "If you can't explain it simply, you don't understand it well enough"
    Albert Einstein
    mattmia2Gordy
  • mattmia2
    mattmia2 Member Posts: 9,747
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    You can buy a lot of propylene glycol for what the backflow prevention device that you would require for methanol would cost.
  • Jamie Hall
    Jamie Hall Member Posts: 23,436
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    All these^^^ plus: methanol mixtures have a lower boiling point -- which can be within the range of the higher temperatures of a heating system. Somewhere around 170, varying with concentration. This you do not want, as the resulting vapour coming from your "air" eliminator is highly flammable.

    Don't use it as an antifreeze in your diesel truck, either -- pretty well guarantee a runaway engine, which is not pretty.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • ethicalpaul
    ethicalpaul Member Posts: 5,734
    edited February 2020
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    I'm not sure where you got that methanol is preferred for geothermal...maybe once it was or among certain areas or something.

    But when I hired an engineer to size my system I installed in CT, he said "use glycol" and I did.

    My system had a closed ground loop so there was no back flow stuff required (if I'm understand the above comment correctly).

    Edit: It strikes me that you might be talking about the radiant loop though. I want to be clear my use of glycol was in a closed ground loop.
    NJ Steam Homeowner. See my sight glass boiler videos: https://bit.ly/3sZW1el
  • GW
    GW Member Posts: 4,701
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    OK thanks, I’ll stick to the good old fashion glycol.
    Gary Wilson
    Wilson Services, Inc
    Northampton, MA
    gary@wilsonph.com
  • GW
    GW Member Posts: 4,701
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    Paul what is your geothermal system running out for temperature? I have Geothermal as well, no anti-freeze. Most of our systems run without antifreeze. The lady that I mentioned, needing to order antifreeze, she’s keeping our house at 75°.
    Gary Wilson
    Wilson Services, Inc
    Northampton, MA
    gary@wilsonph.com
  • mattmia2
    mattmia2 Member Posts: 9,747
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    not sure how the specific heat of methanol compares to water, i know it is a fair bit less for propylene glycol
  • ethicalpaul
    ethicalpaul Member Posts: 5,734
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    > @GW said:
    > Paul what is your geothermal system running out for temperature? I have Geothermal as well, no anti-freeze. Most of our systems run without antifreeze. The lady that I mentioned, needing to order antifreeze, she’s keeping our house at 75°.

    I sold that house, but I would start out in the fall with water coming in at 55 and by Spring it would be coming in at 45 or so. I had the flow damped down to give me a 10 degree delta, so the outgoing water would get close to freezing.

    The glycol was a “just in case”...I’m not sure I ever hit 32 but someone running warmer temps probably would, like your 75 degree customer
    NJ Steam Homeowner. See my sight glass boiler videos: https://bit.ly/3sZW1el
  • GW
    GW Member Posts: 4,701
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    Yes I’m such an anti antifreeze guy i would rather roll the dice and see if it freezes up. Seems like your engineer is simply more of a rubber stamper. If the performance is good and you’re happy that’s all that matters
    Gary Wilson
    Wilson Services, Inc
    Northampton, MA
    gary@wilsonph.com
  • clammy
    clammy Member Posts: 3,113
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    GW I know another hvac contractor who uses a corn based anti freeze in process cooling and geo therm .states it’s cheaper and doesn’t break down nor go acidic I really never looked into I believe it was a Dow chemical product ,but I sure it was corn based product ,at the time I thought nothing of it and did ask for more info should have .i know it was also food safe being it was being used flash freezer application w some sort of barometric freezer , I was there for the chiller replacement had other concern . Check Dow,s product line peace and good luck clammy
    R.A. Calmbacher L.L.C. HVAC
    NJ Master HVAC Lic.
    Mahwah, NJ
    Specializing in steam and hydronic heating
    GW
  • Solid_Fuel_Man
    Solid_Fuel_Man Member Posts: 2,646
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    Use vodka! I'd go bottom shelf for such purposes though.... :D
    Serving Northern Maine HVAC & Controls. I burn wood, it smells good!
    GW
  • hot_rod
    hot_rod Member Posts: 22,256
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    Some pump folks consider it a flammable liquid. Common circulator are not approved for pumping those.
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
    GWmattmia2
  • ethicalpaul
    ethicalpaul Member Posts: 5,734
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    > @GW said:
    > Yes I’m such an anti antifreeze guy i would rather roll the dice and see if it freezes up. Seems like your engineer is simply more of a rubber stamper. If the performance is good and you’re happy that’s all that matters

    No, I dont think he was a rubber stamper. He was a long-time geothermal proponent and impressed me with his care and calculations. He did a very detailed heat loss calculation on my house.
    NJ Steam Homeowner. See my sight glass boiler videos: https://bit.ly/3sZW1el