IC tubing size...length vs diameter 1/4, 3/8 ?

[odie]

Thinking about making a new IC. Everyone goes with 3/8 but I kinda gather that's only because its easier to make the garden hose connection.

would a longer 1/4 IC be better than a shorter 3/8 IC? Assuming IC volume and flow rate was the same? Would it pull heat faster?

Related question, what flow rate do y'all use with your IC and why? I run kinda slow so more heat is absorbed by the water. If it's too fast the water comes out barely warm. which would cool faster?

 

[apache_brew]

You’ll likely run into high pressure and flow restrictions with 1/4” tubing. Check what the head drop of it is prior to purchasing material. I think 50’ 3/8” is the way to go, or copy the “hydra” and make it a parallel run with 2 or 3 lines to reduce back pressure and increase contact time.

 

[odie]

well I currently turn down the flow significantly on my 3/8 IC otherwise the water out is lukewarm at best. Too fast and I think I'm leaving too much heat in the wort and wasting too much water.

 

[apache_brew]

Are you set on sticking with an immersion style? If you're already using a pump, a counter flow would be a great option. Once I bumped up to 10+ gallon batches, a friend gave me his old 25' counter flow chiller. From a boil, it gets me down to 75F with 55-60F tap water. I've since repurposed my old 25' 3/8" IC and put it into wort cooling loop downstream of the counter flow chiller with some stainless compression/camlock fittings. On brew day, I buy 40 lbs of ice and dump it into a spare ice chest, fill with water, and submerge the IC into the ice bath. If I don't constantly shake the IC in the ice bath to keep things turbulent, my wort into my fermenter is 60F. If shaken, 45F.

 

[day_trippr]

The notion of slowing the flow rate through an IC being more efficient than unthrottled flow is a common misconception.
Regardless of diameter, an IC should see the full available flow from its cooling water source if rate of cooling is important.

Same for diameters: if cooling speed is a concern, the wider the better (to a point less than silly) as the surface area increases geometrically.
I built a full copper 3/8" diameter 50' long IC many years ago and it worked quite well for five gallon batches, could drop to pitching temperature in 8 to 13 minutes depending on the time of year, but it was under-gunned for 10 gallons. My 50' 1/2" SS IC will drop 10 gallons to pitching temperature in 15-20 minutes, and I never have to worry about verdigris...or Fenton reactions...

Cheers!

 

[Bobby_M]

My IC is two parallel 25ft runs of 1/4" OD tubing and the flow is slower than I'd like. I'm planning to make a new one with three 15ft parallel runs of 5/16" OD.

 

[Kerrden]

3/8” OD tubing has 50% more surface area than 1/4” OD tubing.

 

[odie]

3/8” OD tubing has 50% more surface area than 1/4” OD tubing.

yes but my thought was using twice the length of 1/4 line. Since the 3/8 line is so much wider, the center flow of water picks up very little heat, only the water in contact with the copper. I figured 1/4 line will have less water staying cooler in the center but a longer overall run would absorb more heat (if not as least as much) than a 3/8 line half as long.

 

[odie]

I guess which would remove more heat per gallon of water used? More efficient use of water, not fastest rate of cooling. I thought the larger diameter line would have a greater volume of water pass but absorb less BTU per gallon of flow?

 

[Kerrden]

yes but my thought was using twice the length of 1/4 line. Since the 3/8 line is so much wider, the center flow of water picks up very little heat, only the water in contact with the copper. I figured 1/4 line will have less water staying cooler in the center but a longer overall run would absorb more heat (if not as least as much) than a 3/8 line half as long.

I guess if you double the length then you would have more surface area with the 1/4” tubing, but the longer the tubing the more pressure loss, so your water velocity will slow down so in effect you will have less water moving through your hoses. I also think the cooler water in the center is pulling the warmer water near the wall away.

 

[day_trippr]

[...]Since the 3/8 line is so much wider, the center flow of water picks up very little heat, only the water in contact with the copper.[...]

That would take an impossibly laminar flow the entire length of the coil. Ain't gonna happen.

And I doubt doubling the length of the thin tube coil would achieve a significant gain because the cooling water will reach the wort temperature well before it exits the coil - all that extra length beyond that point would be wasted.

Cheers!

 

[Kerrden]

It may seem like it’s not picking up the heat, but there is more cold tap water for the heat to be dispersed in so it wouldn’t feel as warm.

 

[odie]

All good points above...sounds like there is no clear advantage to either thin and long or wide and short. Either will result in fairly similar total IC volume, surface area and thermal transfer properties (efficiency and rate). So pick whichever design you find the easiest to make or the cheapest to make depending on what is available to you at your fav hardware store.

 

[Bobby_M]

It's not just about surface area because any copper where the maximum heat has already been absorbed is a waste. That's why parallel runs are so much more efficient than long single runs.

Even though 50ft of 3/8" has the same surface area as 75ft of 1/4", a chiller made with three parallel runs of 25ft x 1/4 would outperform the 50 x 3/8 in spades.

 

[ATLBeer]

Anyone have a source for a good Y fitting to make a dual run chiller? Either 3/8 or 1/4.

All I find are cheap Chinese pieces that look pressed or something. I can sweat copper but don’t want to fab something and don’t want to do it on the hose.

 

[odie]

It's not just about surface area because any copper where the maximum heat has already been absorbed is a waste. That's why parallel runs are so much more efficient than long single runs.

Even though 50ft of 3/8" has the same surface area as 75ft of 1/4", a chiller made with three parallel runs of 25ft x 1/4 would outperform the 50 x 3/8 in spades.

I've got a 3/8 chiller and I had a coil of 3/8 that I just added to the end...the output is way too cool unless I slow down the flow. That's why I'm thinking it's not performing at it's max since it's overly long verses shorter parallels.

 

[Bobby_M]

I've got a 3/8 chiller and I had a coil of 3/8 that I just added to the end...the output is way too cool unless I slow down the flow. That's why I'm thinking it's not performing at it's max since it's overly long verses shorter parallels.

That leads me to believe you're not stirring the wort which is the most impactful aspect of immersion chilling. Maybe you are stirring but if not, try that first.

 

[odie]

That leads me to believe you're not stirring the wort which is the most impactful aspect of immersion chilling. Maybe you are stirring but if not, try that first.

nope...not that...

 

[odie]

I installed a couple 3/8 wye or tee fittings and paralleled both 3/8 coils....seems to work faster. not a whole lot faster than the series run but certainly noticeable IMO.

 

[bionicbelly]

Anyone have a source for a good Y fitting to make a dual run chiller? Either 3/8 or 1/4.

All I find are cheap Chinese pieces that look pressed or something. I can sweat copper but don’t want to fab something and don’t want to do it on the hose.

I made an immersion chiller with two runs of 1/4 inch copper, fed by 3/8. I used a 1/2" x 3/8 reducer, put the 3/8 on the 3/8 feed line, put the two 1/4 legs in the 1/2 part of the reducer, and used a hammer and chisel to form it up a bit, and soldered it up. Works great.

 

[bionicbelly]

I made an immersion chiller with two runs of 1/4 inch copper, fed by 3/8. I used a 1/2" x 3/8 reducer, put the 3/8 on the 3/8 feed line, put the two 1/4 legs in the 1/2 part of the reducer, and used a hammer and chisel to form it up a bit, and soldered it up. Works great. I couldn't find any sort of y fitting, or I would have used that.

 

[bionicbelly]

Thinking about making a new IC. Everyone goes with 3/8 but I kinda gather that's only because its easier to make the garden hose connection.

would a longer 1/4 IC be better than a shorter 3/8 IC? Assuming IC volume and flow rate was the same? Would it pull heat faster?

Related question, what flow rate do y'all use with your IC and why? I run kinda slow so more heat is absorbed by the water. If it's too fast the water comes out barely warm. which would cool faster?

I used 1/4" for my chiller. I started with a single run/coil, but it did not flow enough to do much. It works, it was just really slow. I added a second 1/4" coil and fed them both off a 3/8 line. Works like a champ now. Cools a 5 .5 gallon batch in less than 20 minutes with a total of 75 feet of 1/4" line.