Antifreeze Question

Discussion in 'General Discussions' started by Karla Glidden, Apr 25, 2021.

  1. Karla Glidden

    Karla Glidden New Member

    Looking for some help regarding antifreeze in loops. The contractor believed my loops contained methanol. Have not been able to find out when methanol could no longer be used in Iowa. This was replaced with propylene glycol. However, contractor dumped that methanol in my yard. I am looking to find out how this will affect the ground. My 3 dogs got very ill at the same time. I am thinking the methanol as they only go out in my fenced backyard. Any ideas how to make my backyard safe again. Thank you.
  2. gsmith22

    gsmith22 Active Member Forum Leader

    methanol is toxic and likely why your pets got sick. How to clean up your yard? your question is better directed to an industrial hygienist who specialize in that sort of thing. Your contractor should have used ethanol instead of PG. Ethanol is non toxic and much less viscous than PG at cold temperatures. To pump the fluid around your closed loop during winter, your pumps now have to work harder so your costs to heat are going to go up with the use of PG. Ethanol is slightly more viscous than methanol at cold temps (which is why people use methanol when they can). Using ethanol probably would be indistinguishable from a methanol from a pumping cost perspective.
  3. Karla Glidden

    Karla Glidden New Member

    I am very appreciative of this response. I will look into cost of replacing PG for Ethanol by a different contractor. As well, try to find the industrial hygenist to help me with the yard.
  4. gsmith22

    gsmith22 Active Member Forum Leader

    I should clarify one aspect - depending on the hydraulics of your closed loop and the type of pump you have, there can be several outcomes. My response above probably made too many assumptions. Since PG is more viscous at low temps than methanol, the fluid is harder to pump resulting in more head loss per input pump energy. If you have a variable speed flow center pump, the pump should raise its speed to combat that issue so this will result in your heat pump system putting out the same amount of heat although expending more energy to do so (pump speed is higher). If you have a single speed flowcenter pump (and I am guessing this might be the case), head loss went up with the use of PG (relative to methanol) but since the pump only runs at one speed, there will be less flow for that single speed (ie you are moving left along the pump curve). (Making up numbers) if your heat pump requires 9gpm but will now only get 7 or 8 gpm (flow reduced because of more head loss in closed loop), the heat pump won't put out as much heat because the flow is lower. If your heat pump requires 9gpm but was getting 12 gpm before and will now only get 10gpm, there won't be any issue with the heat pump output becuase its still above a suitable level for the heat pump. Sorry about my prior response as you can see its more nuanced.

    I don' t know what happens with methanol - maybe it is volatile and all evaporates but I doubt it. Presumably it is water soluble (it was in your loop) and thus rain and ground water can move it elsewhere. So its best to get on that as soon as possible so you don't end up with a (potentially) toxic plume into the ground water table. Maybe this is overexaggerating but don't take it lightly. Contractors can disappear like a fart in the wind but you will you live there and will likely be held responsible by a local health department or state EPA, especially if they can't track down who did it.
  5. waterpirate

    waterpirate Well-Known Member Industry Professional Forum Leader

    How many gallons got pumped into the back yard, and what was the concentration level? These two questions should help you decide what course of action to proceed with moving forward. Not dealing with the contractor who " dumped/pumped the loop contents into your yard would be prudent. I would however contact the owner of the company and ask if pumping loop fluid suspected of containing methanol into a customers yard is accepted industry standards.

    I used methanol for years. It is a chemical compound with a msds safety sheet. I have since switched to PG to mitigate the potential for fire associated with methanol, not its toxicity.

  6. gsmith22

    gsmith22 Active Member Forum Leader

    methanol is definitely toxic but you probably have to be drinking it (like your pets) or submerged in it to cause a reaction. It is quite flammable as Eric notes. Some google searching looks like it has a biodegradable half life of a week which would suggest by the time you went to remediate any of it, it would probably be largely gone. So maybe its not a long term issue for your yard. Obviously the amount that got dumped and where it got dumped matters. Anything "downstream" of the dump that can get affected? like your well or a stream? I could see it showing up in a shallow well and needing to avoid drinking from that for maybe a month or more (to be safe). Its really hard to know which is why I think environmental science types would be better to consult.

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