is another reason wort chillers work because they keep the lid off

[HibsMax]

This is my wort chiller water saving process :



My rain barrel is split right now so I am not really saving water but when I replace the barrel things will be better.

I like the idea of reducing the water flow to use less water and also cool more efficiently.

I had another idea that I have not tried yet, and probably won't because I don't really need to but it's something like this....

Have a cooler full of ice water. In that cooler you should put a "wort chiller". In your brew pot you should have your actual wort chiller. Use a pump to pump the ice water through your wort and then back to the cooler, through the other wort chiller and back into the ice water. I know that the warmer water coming from the wort will speed up the ice melting process but I don't know at what rate. If you can chill your wort before your ice melts then it could be a good way of chilling your wort without wasting too much water. You do need a second wort chiller / heat exchanger, a pump and some bags of ice so I am not saying this will be more cost effective but for those people concerned about just flushing all that water away, it might be worth a shot.

 

[ludomonster]

This is my wort chiller water saving process :

I like the idea of reducing the water flow to use less water and also cool more efficiently.

Newton's Law of cooling shows an exponential relationship. The water heats at the same rate, assuming no losses to the copper. But as the water heats, it will absorb less energy. You will then need more water to cool the wort. So while the chilling time may relate to the flow rate in such a general way that a high flow chills faster and a low flow rate chills slower, the total volume of used water may not have such a relationship.

Even when you use a high flow rate, as the wort temperature gets close to the coolant temparature, it will take increasingly longer to chill. As the temperature difference approaches zero, so does the time rate of energy transfer. The amount of water you need to chill the wort will climb dramatically. With a lower flow rate, there will be more warm water performing the transfer. You may end up using more water altogether.

 

[BrewinHooligan]

This is my wort chiller water saving process :

I had another idea that I have not tried yet, and probably won't because I don't really need to but it's something like this....

Have a cooler full of ice water. In that cooler you should put a "wort chiller". In your brew pot you should have your actual wort chiller. Use a pump to pump the ice water through your wort and then back to the cooler, through the other wort chiller and back into the ice water. I know that the warmer water coming from the wort will speed up the ice melting process but I don't know at what rate. If you can chill your wort before your ice melts then it could be a good way of chilling your wort without wasting too much water. You do need a second wort chiller / heat exchanger, a pump and some bags of ice so I am not saying this will be more cost effective but for those people concerned about just flushing all that water away, it might be worth a shot.

I have a friend who does this with a pond pump. The first few mintues the chiller water comes from the garden hose and is pumped to the lawn. After the temps drop to around 100, the water is switched to the ice water with a pond pump and he dropps from boiling to under 70 in 10-15 minutes. Not really a cheap method, but it works incredibly well.

 

[HibsMax]

Newton's Law of cooling shows an exponential relationship. The water heats at the same rate, assuming no losses to the copper. But as the water heats, it will absorb less energy. You will then need more water to cool the wort. So while the chilling time may relate to the flow rate in such a general way that a high flow chills faster and a low flow rate chills slower, the total volume of used water may not have such a relationship.

Even when you use a high flow rate, as the wort temperature gets close to the coolant temparature, it will take increasingly longer to chill. As the temperature difference approaches zero, so does the time rate of energy transfer. The amount of water you need to chill the wort will climb dramatically. With a lower flow rate, there will be more warm water performing the transfer. You may end up using more water altogether.

Thanks for that! I guess I should be a little more scientific and actually measure these things. It shouldn't be hard for me to measure flow rate, just measure the water as it comes out the chiller. Then time how long it takes to cool from X to Y at different stages of the process. Sounds like a fun project.