I've felt a lot safer using methanol as a lab burner fuel for years and 3 months in a chiller rather then needing a higher ratio of ethanol which makes the beer cooler a giant bomb. Kind of odd to read about people playing with high pressure flammable gas, electricity and water but methanol is dangerous and cannot be used!

It eats aluminum viciously but no serious WC loop has exposed alu or lack of corrosive inhibitors...doesn't even seem to clean the oxide off copper.

If you are worried someone might come in and drink it, bring Everclear as the counter to methanol poisoning is drunkeness, the body will metabolize the ethanol harmlessly. Methanol is metabolized into formaldehyde but it cannot happen if the body is metabolizing ethanol instead.

I had Zerex in my chiller but I am not sure it would make a noticable impact in temperatures, I had it for the corrosion inhibition. 3 months everything is okay and then suddenly the zinc anodized evaporator's steel components instantly rust up. You have a nice clean professional chiller, doesn't matter.

NOL is right about the TECs, it helps less in cold I've tried. The effect is still there at your planned temps so its a good idea for benching but obviously 24/7 be prepared for a hefty power bill.