With the price of copper so high, I was looking for ways to make a cheaper chiller that still had the same efficiency as the more expensive counterparts. I was using Lowes/HD prices for my comparisons and I found the following prices:
1/2" OD = $3/ft
3/8" OD = $1.60/ft
1/4" OD = $.60/ft (20 ft lengths only... any longer and it goes to $1.20/ft)
Clearly 1/4" at 20' lengths was the cheapest option but could it work as well as the larger diameters? I decided that $25 is worth the try.
I believe the biggest flaw in most immersion chiller designs is how much cross sectional area of wort is ignored or avoided. The coil is usually closer to the outside of the brewpot leaving a large cylinder of wort in the middle untouched. The coil is also tightly packed, tube to tube, which doesn't let much hot wort get in between considering the cooling power of each copper tube "radiates" around it.
My design compensates by leaving a large gap between each turn of the coil, and also doubling the coil to cover more cross sectional area. The inner coil is 5" in diameter and uses 20ft of 1/4" copper and the outer coil is about 11" in diameter and also uses 20ft of tubing. I tacked each turn of the outer coil to the section of upright tubing with a spot of lead-free solder to make the structure more rigid.
Basically the two coils join together at the input and output (also soldered together). To keep the project really cheap, I put a glob of devcon two-part metal epoxy on each end and sanded it round in order to clamp my vinyl tubing directly on without using compression fittings, tees, and reducers.
This design brought 6.5 gallons of boiling water(212dF) down to 120dF in 6 minutes using 68dF tap water through the coil. This was done without stirring the wort or disturbing it in any way.
My only issue with this build is that I didn't make the input and output runs long enough to bend over the top of the brewpot so my vinyl lines get a little close to the top edges of the pot. Then again, it's a tall, but skinny 30qt pot designed for turkey frying.
Bobby
1/2" OD = $3/ft
3/8" OD = $1.60/ft
1/4" OD = $.60/ft (20 ft lengths only... any longer and it goes to $1.20/ft)
Clearly 1/4" at 20' lengths was the cheapest option but could it work as well as the larger diameters? I decided that $25 is worth the try.
I believe the biggest flaw in most immersion chiller designs is how much cross sectional area of wort is ignored or avoided. The coil is usually closer to the outside of the brewpot leaving a large cylinder of wort in the middle untouched. The coil is also tightly packed, tube to tube, which doesn't let much hot wort get in between considering the cooling power of each copper tube "radiates" around it.
My design compensates by leaving a large gap between each turn of the coil, and also doubling the coil to cover more cross sectional area. The inner coil is 5" in diameter and uses 20ft of 1/4" copper and the outer coil is about 11" in diameter and also uses 20ft of tubing. I tacked each turn of the outer coil to the section of upright tubing with a spot of lead-free solder to make the structure more rigid.
Basically the two coils join together at the input and output (also soldered together). To keep the project really cheap, I put a glob of devcon two-part metal epoxy on each end and sanded it round in order to clamp my vinyl tubing directly on without using compression fittings, tees, and reducers.
This design brought 6.5 gallons of boiling water(212dF) down to 120dF in 6 minutes using 68dF tap water through the coil. This was done without stirring the wort or disturbing it in any way.
My only issue with this build is that I didn't make the input and output runs long enough to bend over the top of the brewpot so my vinyl lines get a little close to the top edges of the pot. Then again, it's a tall, but skinny 30qt pot designed for turkey frying.
Bobby