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Overshoot glycol target. 45% instead of 35%

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WillC
WillC Member Posts: 37
in Radiant Heating

Hi there,

My math were not right. I am seating at 45% glycol. Heated house and heated attached garage north of North Dakota.

We are gonna do our basement with hydronic in 1 year from now. Can we wait 1 year and dilute later?

If not, can I remove and store some 45% glycol mix in a airtight container and keep if in a cool/dark place for 1 year?

Thanks!

Comments

  • pecmsg
    pecmsg Member Posts: 6,982

    That's a little high. How many gals did you figure? 30% is high for a heating system.

    GroundUp
  • ChrisJ
    ChrisJ Member Posts: 17,209
    https://forum.heatinghelp.com/discussion/comment/1887364#Comment_1887364

    Looks like almost all design temps in North Dakota are far below 0F with -18F being common and some dipping down to -20F.

    Single pipe 392sqft system with an EG-40 rated for 325sqft and it's silent and balanced at all times.

  • pecmsg
    pecmsg Member Posts: 6,982
    edited February 11

    This is a heating system not a chiller that is sitting outdoors. All the glycol does is to allow time for power to be restored. Even at 20% freeze protection that's roughly +20°F protection and a -30 freeze point.

    30% is roughly a 10 - 15% loss in heat transfer.

    GroundUp
  • WillC
    WillC Member Posts: 37

    I was told less than 30% and the mix of water/glycol will favour development of bacterias. That's why the local guys shoot for 35%.

  • Intplm.
    Intplm. Member Posts: 2,960

    What's the concern? Is too much or more glycol detrimental. If it is, when do the benefits surrender to a problem?

  • pecmsg
    pecmsg Member Posts: 6,982

    the ability to transfer heat suffers. More glycol less heat transfer in and out.

  • Jamie Hall
    Jamie Hall Member Posts: 27,125

    All of the above are technically true.

    HOWEVER in real life in your heating system it's not going to make a measurable difference. Move on.

    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • Intplm.
    Intplm. Member Posts: 2,960

    Yes. Ok. How does the numbers that @WillC post above need to be addressed. For practical reasons this is a none issue. His system is simply protected at a lower temp. while needing to work a little harder…a (little) harder as a trade off.

  • pecmsg
    pecmsg Member Posts: 6,982

    A little harder and higher operating costs.

    Less is better.

    WillC
  • WillC
    WillC Member Posts: 37
    edited February 11

    My concern was having the pumps work harder and the heat not transferred properly. Since my plumber is on site today, I'd rather empty some mixture and add water in today, so I get closer to the 35% I was told to use

  • Intplm.
    Intplm. Member Posts: 2,960
    edited February 11
    https://forum.heatinghelp.com/discussion/comment/1887380#Comment_1887380

    If you are in it now sure, go ahead and do a redo of the glycol. If for nothing else but piece of mind. I have had similar numbers on cast iron boilers with Finn tube radiation as well as other types of systems over the past decades and not had much of an issue. This includes numbers at my own home. Nothing wrong with getting the numbers right while working there. If you had left and this was an after thought, I would have said to not lose any sleep over it.

    What type of glycol? Non-toxic? I hope. What brand? What do the directions say?

  • pecmsg
    pecmsg Member Posts: 6,982
    https://forum.heatinghelp.com/discussion/comment/1887380#Comment_1887380

    The plumbers there then by all means get it right.

    Where did you get the 35% from?

    Intplm.
  • GGross
    GGross Member Posts: 1,819

    Just FYI they make pre-mix glycol and not only do you not have to worry about blending correctly, but the water in there is treated and DI, and the leftover is ready to be added directly to your system should you need to add fluid.

  • WillC
    WillC Member Posts: 37
    edited February 11

    It is 100% propylene glycol. No brand I could find, it comes directly from a local company that specializes in building/selling hydronic systems. No direction included, I was told to use a 35% ratio by these guys.

  • Intplm.
    Intplm. Member Posts: 2,960
    edited February 11

    Hmm… It should be labeled non-toxic. Especially if you have a source of make up water feeding the system.

  • WillC
    WillC Member Posts: 37
    https://forum.heatinghelp.com/discussion/comment/1887387#Comment_1887387

    I checked again, nothing about it being non-toxic. I have a backflow preventer valve after the make up water system though.

  • Jamie Hall
    Jamie Hall Member Posts: 27,125

    Oy. Unless it's a reduced pressure zone backflow preventer, it's not adequate protection.

    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • GGross
    GGross Member Posts: 1,819

    I should really hope that what you had is NOT 100% propylene glycol, no boiler antifreeze is 100% PG its all a blend, if you mix noburst -100 50/50 you will get around 40-45 ish percent. Any boiler antifreeze has a proprietary blend of chemicals in it as well to make it more suitable for a boiler system. It's never 100% PG, and if it is then buy something else thats specifically designed for a boiler system. Whether non-toxic or not you still need a backflow on the makeup water, boiler fluid isn't safe to backflow into potable water

  • GroundUp
    GroundUp Member Posts: 2,495

    The small reduction in heat transfer isn't of concern. Just leave it alone and correct the concentration with the proper inhibitors next year when you add the basement.

    @GGross yes there are several PG manufacturers that will supply 100% (or very close) solution with inhibitors for whatever the ending solution might be. I have gotten it from Dow as well as Fremont inhibited for a final 33% solution (2 parts DI to 1 part PG mixed at my shop), and I know Cryo-Tek sells their AG fluid as 96% concentration. Also NoBurst -100 and Cryo-Tek -100 are both 55% as sold so a 50/50 is 27.5%.

  • WillC
    WillC Member Posts: 37
    https://forum.heatinghelp.com/discussion/comment/1887391#Comment_1887391

    There is also that. There is the water make up system, the backflow preventer valve and the pressure reducer, then it goes in the closed loop system.

  • WillC
    WillC Member Posts: 37
    edited February 11

    I just confirmed with the manufacturer, it is non toxic glycol. Thanks everybody for the help.

  • WillC
    WillC Member Posts: 37
    https://forum.heatinghelp.com/discussion/comment/1887394#Comment_1887394

    Right, I am just going to wait till the basement is done.

  • hot_rod
    hot_rod Member Posts: 27,171

    You might disconnect the fill system, there is no need for it on a glycol system.

    The % vs freeze protection temperatures vary a bit from brand to brand, depending on the inhibitor mix.

    I would leave it be for now if the system is heating adequately. Check the % with a refractometer at seasons end, check ph also.

    The container should be labeled and a MSDS sheet included to indicate what the fluid is comprised of.

    You should also put a label on the system indicating it has glycol, the brand and %. Sometimes a label is included with the product.

    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
    WillC

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