How much Antifreeze?

[KirstenHW]

So if the freeze protection is based on % AF to H2O, say there's a quart of H2O in the line plus a gallon of AF. And it gets cold - 32 degrees or lower, and the line is 2 feet down - is the AF useless then? Thx

[waste]

So if the freeze protection is based on % AF to H2O, say there's a quart of H2O in the line plus a gallon of AF. And it gets cold - 32 degrees or lower, and the line is 2 feet down - is the AF useless then? Thx

Kirsten, for exaple purposes only I'll make up some numbers (I don't have a bottle in front of me so the numbers are 'rough' and for illistrative purposes only). Say that 100% propoline glycol will not freeze until the temp reaches -30 deg. If it's diluted to 75% with water, the freeze temp rises to ~ -20 deg. , and at 50% dilution the protection is ~ -8 deg. The drop off in protection is probably more linear than this, but it serves as an example. The higher the % of AF to h2o, the better it protects.
At 32 deg water freezes, with some AF in it, the water will not freeze at 32, but how much lower the freeze point is, is dependent upon the % of AF to h2o. At 2' underground, the h2o filled pipe won't freeze until the ground temp surrounding the h2o filled pipe reaches ~32 deg ( it's actually higher because of the pipe that is 'air filled' runs through already frozen ground). As AF is cheep, when compared to the cost of digging up and replacing an ice busted line, I recommend some - how much varies with your local winter conditions and whether the pipes were run deep enough.
(I'm not real happy with this answer, but it's the best I can do for right now )