Does it matter if I use Methanol or Glycol ?

My Distributor only carries Glycol, His calculator came up with the same amount I had figured for Methanol

It is 15.00 Per Gallon for Glycol I need about 60 Gal for a 20% solution.


Thanks for the info
Ed

Your design needs to take into account the antifreeze.  Methanol has a higher heat transfer coefficient and lower viscosity so it is easier to pump than Glycol and can require less pipe.

-Adam

Yes, to your wallet....
As was already mentioned meth transfers heat better and is about a 10th the cost.
There is a movement afoot however to only permit the use of food grade prop glycol in our loops.
joe

When we refilled our hydronic heat system with propylene glycol the system started carrying a lot more heat from the boiler into the house. Plus, when the gas goes off, or the electric, the system won't freeze. And prop glycol is non-toxic, especially when compared to methanol, which damages nerve tissue at a pretty small dosage. Ethylene glycol is also toxic at low dosages. Prop glycol is more expensive than plain old water, but the advantages are clear.

It seems like a no-brainer to me. We got it cheap as a neighbor worked at a dairy where they used it a lot, she got 10 gallons at cost, like 40 or 50 dollars, it's worked well even since. I'll do the same out in Arizona once we get to implementing the liquid-based systems on that project.

We use methanol in all of our systems.

Methanol will be more corrosive on the pump. The food grade PG is safer but really, since it is a closed loop I can't see the concern. Also methanol is biodegradable as is the PG.

Whatever antifreeze fits your budget works best, PG seems to be on the expensive side currently. Just keep in mind the percentage should be appropriate for your system, I see many installers providing much more antifreeze than necessary. For instance if your heat pump trips off at 25°F, why protect your fluid any lower? 13% PG will protect down to 25°F so why put 20-25% PG in the system? It just cost more all the way around.