25ft vs 50ft immersion chiller (5 gallon batches)

[IceFisherChris]

25 or 50 foot... either way you're going to have a good set up.
It beats buying ice and cooling in your sink, and personally I think that is the best part about it. Obviously a foot 50 coil will cool faster. If you don't think so, then you know nothing about thermodynamics. I have a 50 foot 3/8" chiller and it will cool 4 gallons in about 5 minutes (using input water of about 55 degrees)
Stirring your wort is the most important part. Your 25 foot chiller would work faster than my 50 foot, granted you stirred and I didn't.

I think you'll be happy with a 25 foot chiller, and a little happier with a 50 foot chiller.

 

[techrunner]

i did a quick numerical calculation, a while ago. i got somewhere around 6.8 feet i think, but that was very rough. i actually treated the coil as a mass, and looked at the temperature only. it will depend on the flow rate through the coil, and i guess when i did it i was assuming that the flow would be very low, due to the fact that i was planning on recirculating ice water. if you know roughly your pressure at the tap, you would need that to determine the flow rate, then use that to determine the heat transfers based on how fast the water was moving. i kinda gave up on it after that first pass, i just had a ballpark number and got my 25' copper coil. i haven't gotten a pump yet to have flow specs to work with. obviuosly the flow of water will move the point at which the cold water reaches temperature equilibrium with your wort farther down, but i cant see te increase in cost for the 50' coil really doing you much good. 10 gallons, maybe, might save 2-3 minutes, but still not going to be a huge deal. i might have to revisit that problem now though, this thread kinda got me thinking again.

 

[Synovia]

25 or 50 foot... either way you're going to have a good set up.
It beats buying ice and cooling in your sink, and personally I think that is the best part about it. Obviously a foot 50 coil will cool faster. If you don't think so, then you know nothing about thermodynamics. I have a 50 foot 3/8" chiller and it will cool 4 gallons in about 5 minutes (using input water of about 55 degrees)
Stirring your wort is the most important part. Your 25 foot chiller would work faster than my 50 foot, granted you stirred and I didn't.

I think you'll be happy with a 25 foot chiller, and a little happier with a 50 foot chiller.

The rate at which a chiller cools the wort is completely dependent on the temperature gradient between the coolant and the wort. Using copper, in the sizes we use, the coolant is the same temperature as the wort within a matter of feet.

Unless you're running 50 degree water through one at very high velocity, a longer chiller will not make any difference.


IF you want to cool faster, there are 2 ways to do it:

1) Push MORE water through. (via higher velocity, or multiple tubes)

2) Push COLDER water though.

 

[The Pol]

I have a 50' coil... it will be FULLY submerged in a 10 gallon batch, it will only be HALF submerged in a 5 gallon batch...

It would be a waste in a 5 gallon batch in my case, to have more than 25'

 

[IceFisherChris]

The rate at which a chiller cools the wort is completely dependent on the temperature gradient between the coolant and the wort. Using copper, in the sizes we use, the coolant is the same temperature as the wort within a matter of feet.

Unless you're running 50 degree water through one at very high velocity, a longer chiller will not make any difference.


IF you want to cool faster, there are 2 ways to do it:

1) Push MORE water through. (via higher velocity, or multiple tubes)

2) Push COLDER water though.

You're partly right, but only for the first 30 seconds or so of chilling. A 25 and 50 foot coil will suck away the same amount of heat if they have the same water flow and the same output temperature. This situation is where coil length doesn't really matter, when you can't flow enough water to compensate for the extreme amount of heat transfer.
However, once your wort starts to cool, the greater surface area of the 50 foot coil will grab more heat from the liquid.


Guys, the wort is not ALWAYS boiling hot!!! I think everyone is forgetting this. A 50 foot chiller is overkill for boiling wort, because our sinks just can't flow enough water. But for the last 90% of the chilling session, our sinks CAN flow enough water to make a 50 foot chiller work better than a 25 footer. In fact, they could most likely flow enough water to make a 100 foot chiller work fine.

 

[robertvrabel]

I guess this turned out to be a pretty interesting discussion! Seems like everyone has their own views on which is better. What IceFisherChris just said makes total sense to me. I guess the question is, is the 50ft one WORTH the extra the money for the benefits in a 5 gallon batch. If it cools it 1 minute faster, then to me its not worth it... if it was like 2x as fast then I could the benefit. Its clear it would be better, but how much better is the question... since its a lot more $.

As of right now I'm leaning more towards the 25ft one, and I'll spend the extra money on something else for brewing... unless someone can convince me otherwise

 

[ardentfrost]

I guess this turned out to be a pretty interesting discussion! Seems like everyone has their own views on which is better. What IceFisherChris just said makes total sense to me. I guess the question is, is the 50ft one WORTH the extra the money for the benefits in a 5 gallon batch. If it cools it 1 minute faster, then to me its not worth it... if it was like 2x as fast then I could the benefit. Its clear it would be better, but how much better is the question... since its a lot more $.

As of right now I'm leaning more towards the 25ft one, and I'll spend the extra money on something else for brewing... unless someone can convince me otherwise

I got a 25' one and it works, so I'm on that side

Even if the 50' one cooled the wort in half the time, the 25' still cools mine in 12-13 minutes. That's well under Palmer's suggested cool time.

 

[IceFisherChris]

If I had the money, I would definitely be willing to test the difference between a 25 and 50 foot cooler. And no, I won't chop coils off my 50 footer

 

[Dr. Francois]

There's an immersion chiller issue that's been bugging me...

After the cool water intake has reached equilibrium with the wort, wouldn't the rest of the length of copper be irrelevant? For example, if I have a 50' chiller with 190F wort and 60F water, if the water reaches 185 at 32', wouldn't the last 18' be worthless? I suppose it might become useful again as the wort temperature drops more.

Thoughts?

 

[robertvrabel]

There's an immersion chiller issue that's been bugging me...

After the cool water intake has reached equilibrium with the wort, wouldn't the rest of the length of copper be irrelevant? For example, if I have a 50' chiller with 190F wort and 60F water, if the water reaches 185 at 32', wouldn't the last 18' be worthless? I suppose it might become useful again as the wort temperature drops more.

Thoughts?

Basically yes, makes sense that i would become unless past that point. I started this thread a long time ago... and I do now have a 50' chiller because my 25' one was terribly designed (you get what you pay for). Now that I have a 50' one, I can now use it for 10g batches if I choose to do so (which will be a couple times a year).

So I wish I would have just gone with a 50' one from the start. My new one doesn't bend easily (old one crimped) and the connections are MUCH better and don't leak. I purchased mine from morebeer.com

 

[wolverinebrewer]

There's an immersion chiller issue that's been bugging me...

After the cool water intake has reached equilibrium with the wort, wouldn't the rest of the length of copper be irrelevant? For example, if I have a 50' chiller with 190F wort and 60F water, if the water reaches 185 at 32', wouldn't the last 18' be worthless? Thoughts?

Yes, but if this was the case, then you would increase the flow so that particular bit of water is at 185* when it exits the end of the copper. Flow is the key whether you have 25' or 50'. If the outlet water is 100* and wort is 150*, you are going too fast and wasting water (less efficient). It is not removing maximum amount of heat so you would slow down the water. This is where a 50' would be better. The longer that the water stays in the wort removing heat, the faster the wort will cool. This allows you to increase the flow. I guess it comes down to how fast is fast enough for you. If your 25' cools in 12 minutes, does it really matter if a 50' cools in 6 minutes? Not really, both will still make great beer and I believe that's the goal of all of us.
I built my own using 20' of 5/8" OD copper. I figured it would be best to have the greatest amount of surface area working given a certain flow rate. I have to run it pretty slow even with my well water thats 50*.

Great discussion.