Cadbury64 wrote:Antifreeze is usually ethylene glycol or in some case propylene glycol. The presence of the glycol does two important things, it reduces the freezing point of the coolant (at 50:50 to -36C), but it also increases the boiling point (at 50:50 to 107C). Antifreeze also includes corrosion inhibitors (phosphates, silicates or borates) and coloured dye.
The heat transfer effectiveness of a liquid is related to it's specific heat, the amount of energy required to raise one gram by one degree C. Water has a higher specific heat than glycol, so pure water is a better coolant, but for the prevention of corrosion antifreeze should be used, and that also means the cooling system can function over a much wider temperature range.
In the short term running water with a splash of antifreeze would be fine, but I'd feel a lot more comfortable with a proper 50:50 mix in there in the long term. The density of 50:50 water:ethylene glycol would be around 1.07 g/mL at 20C.
yes thats what i was gonna say + it looks nicer in the pot with a colour in it. Pressurising the system also raises the boiling point.