<https://www.inspectorsjournal.com/topic/7096-geothermal-closed-loop-system/#comment-54125>
<http://schema.org/text>
"Explain it? Sure. Water will freeze at 32. If they are extracting all the heat from the water so the temp drops below, they need to have Glycol or (like anti freeze) to keep the water from freezing when it gets below 32. "
<https://www.inspectorsjournal.com/topic/7096-geothermal-closed-loop-system/>