Pex oil?

[bgarrett]

I apologize if this has been covered but the 'search' says it found nothing for 'pex'!

I was talking to a yankee the other day about in floor heating using Pex and he started talking about using oil instead of water.
What kind of oil is used?

 

[jayoldschool]

You don't use oil. You use glycol.

 

[Snake87]

You don't use oil. You use glycol.

Is that because the freezing point of glycol is so low?

I worked for a company that produced fuel tanks for cars. One of our quality tests involved filling the tanks with glycol and freezing them. 4 hours in -40° F, then drop them from 25 feet up. Made a heck of a racket. But the glycol would not be frozen inside, even at 4 hours in that temp.