Some people have used regular automotive antifreeze, which naturally doesn’t freeze but also doesn’t make as much hho gas. Others have added methanol or ethanol alcohol to the units. The problem is that it is hard to keep enough alcohol in the water if your hho unit is hooked up with vacuum and the temperature of the water gets very high during operation. This can cause alcohol to evaporate off, and the lower concentrations can allow the hydrogen generator to freeze at night or when sitting.

Others claim that high levels of electrolyte will stop the generator or lines from filling with ice. I hope to test that later on this year. Without trying a few things after temperatures go below freezing, we won’t know for sure which methods work and which don’t. Hopefully we will be able to stop hho hydrogen generators from freezing and continue to use them to get better fuel mileage all winter.