How much salt for chiller water?

I just finished putting together my whirlpool chiller. It is made from about 60ft. of 1/2" ID soft copper. I plan on recirculating the chill water through the coils with a 200glh pond pump. My question is how much salt should I add to the ice water that I am recirculating? I want to chill it down to 60-65 as fast as possible. The water temperature is rising fast out here in Tucson, Arizona. The ice water will be in my 8 gallon pot. Any idea about how much I should use? Any help would be greatly appreciated. Cheers!

experiment

I Live in Marana AZ.

I brewed last Saturday. 90 degree tap water!!!

It was only 102 degrees in APRIL!!!!!!!

I have the freezer on my kegerator dedicated to making block ice, and it still was not enough for the counter flow chiller. I had to throw in a whole case of chilled V8 vegetable juice cans, and one 20lb frozen beef brisket into my cooler to chill the last few minutes.

I love the idea of salt.

I am thinking of getting a portable swamp cooler. Good to keep me cool while I am brewing, and use it as a pre-chiller for the water that goes into my cooler.

I would have to agree that the only way to figure out how much salt you need is to experiment, but you do not need to do it with 5 gallon batches.

Take a liter of 80 degree water, add 100 milliliters of salt, record the temperature. Repeat with more salt, keep doing it until you reach a diminishing return. Then scale up the recipe to the amount of water you desire.

Ok. I was looking for a max saturation number but I guess I will experiment away.

A ten pound bag of ice and a couple of pounds of salt should get your water down to about -6 degrees F. I use that for ice cream in a churn.

Hope that helps.

bosco

The re-circulation part is where I think so many people go wrong. Rather than recirculate, pump through the chiller and collect the output into a secondary vessel. One pass through the coil when you first run the pump and that water is going to be in the upper 100's at least initially. Why would you contaminate the coldest possible coolant with that much energy? Run it slow, collect the output until it starts coming out at your current tap water temp, THEN direct it back into the resevoir. Until then, if you need to top up the ice, use tap water. It's colder than the output of the chiller.

The other way to do it is to run tap water for the first 3-5 minutes because even 100F tap water has a huge delta to 212F.

If I were going to create a saturated salt water solution, I'd for sure keep it and reuse it. Of course, this requires that you have space in a chest freezer to pull all the heat back out of it for next use.

I wouldn't put any salt in. Run the tap water until the chilling slows down, and then start pumping ice water through the chiller. Go slow. If the water is coming out cold, you're going too fast. You're trying to transfer heat out, not put cold in.

If there's any benefit to salt is that you could put it in a bucket in a chest freezer and get it back to being 0F without it turning to ice. Granted I know the phase change is a way of storing a lot more energy but having 5 gallons of 0F water that doesn't require the melting of ice is a pretty cool idea. The whole volume is available for pumping immediately. This is the same concept as glycol.