Glycol - where to buy and when to replace

[smw]

I have a two-panel closed loop system. At the moment it's empty because of failure of the pressure release valves (which I'm in the process of replacing). Once the system is working, I'll need to get new glycol.

Home Depot used to sell glycol by the gallon, but they no longer do. Any recommendations on where to buy? All online places I've seen seem very expensive. Additionally, what's the recommended time to replace the glycol once the system is working again?

Thanks!

[Naptown]

You don't want the glycol
From homies. What you want is a food grade glycol. If there is an RE michaels near you they should have it

[russ]

Food grade propylene glycol - the other kind like normal antifreeze is quite toxic if ingested

Different uses have different formulations - get the one for solar panels.

Try search

[smw]

You don't want the glycol
From homies. What you want is a food grade glycol. If there is an RE michaels near you they should have it

I assume you mean R.E. Michel Company. Not in my area.

[smw]

Food grade propylene glycol - the other kind like normal antifreeze is quite toxic if ingested

Different uses have different formulations - get the one for solar panels.

Try search

I have searched, haven't found anything reasonably priced. That's why I posted here.

I did determine that Home Depot does sell Cryo Tek 100 (although it didn't originally come up when I searched their site for glycol), which is what my system was originally installed with. Any reason I shouldn't continue using this?

[Naptown]

That will work

[peakbagger]

Re your question about how often to replace, get yourself a PH test kit, test it when new and track PH, if its abused (stagnated and overheated) it will go acidic. I know of at least one system that is 25 years old on the original (toxic) ethylene glycol. The owner checks the PH yearly. Its a flat panel type system. I have heard comments but no hard data that evacuated tubes systems are harder on glycol.

[Naptown]

That sounds like a Reynolds system
Not as much problems in an ethylene glycol system as long as there is not much mixing of metals