HERMS coil diameter question

[boondocksaint]

I'm down to the last couple of critical pieces of my new brew rig, one of which is a HERMS coil. FYSA, I'm building a Kal clone set up with 20 Gal. Ss Brew Tech kettles.

In shopping around for a HERMS coil and debating on tackling the beast myself, I came across Stainlessbrewing's website. Their price for a 1/2" x 50' coil is very reasonable and seems pretty hard to pass up. My only concern is the diameter. On TEB, Kal recommends a 15.5" diameter x 7" high coil. The largest diameter offered on Stainlessbrewing's site is 14".

Would there be much (if any) difference in performance between 14" diameter and 15.5" diameter? As I understand it, it's primarily a matter of keeping all or as much as possible of the coil submerged in order to maximize efficiency, right?

I sent an e-mail to Zach at SB asking about the possibility of making one at 15.5" dia but before I make too big a deal out of it, I figured I'd ask anyone here with experience in these.

Thanks & Cheers!

 

[Rockn_M]

I bought one of Zach's coils and haven't had an issue.

 

[heckels]

You're right in that the more you can keep submerged the better heat transfer you'll have. Personally, my Stout kettle's HERMs coil is only about 6" in diameter and probably only about 25' of tubing. It's not the most efficient thing in the world but it works.

I wouldn't fret over the 1.5" diameter difference if we get by on a 9" diameter difference.[emoji6]

 

[jekeane]

I purchased my coil from stainless brewing and am pleased with the purchase so far.

 

[TechyDork]

What is the height difference between the 14" and 15.5" coil?

The shorter the coil height the less water you will need to cover the entire coil and thus the less energy you will need to maintain your HLT temp.

In my system I have to add water back to the HLT after moving my mash water to the MLT. So the lower i could get the total height of the coil the less water i needed to add back in and thus the lower my temp drops in the HLT.

I have the 50' 1/2" SS coil from StainlessBrewing in a 14" diameter also in a 20G pot, but mine is a Bayou Classic so it is a wider pot. 18" diameter i believe. It works very well, but now that i have used the system a bit I wish I would have gone with a bigger diameter coil just to keep the height down as much as possible.

 

[Bowtiebrewery]

I have the 25' 1/2" coil in my keggle and I do 10g brews and its pretty awesome... No problems with temp drops, and my flow rate is where it needs to be. Just remember, that all components that you are using should be 1/2" to limit any restriction and this will help with keeping your flow-rate up and in turn will keep your temperature adjustments predictable and consistent.

 

[turkeygecko]

I built a Kal clone as well, and went with the Stainlessbrewing 50 ft, 1/2" coil and the thing is awesome. Had a 25 ft 3/8 coil at first, and the heat transfer wasn't sufficient.

 

[TechyDork]

I built a Kal clone as well, and went with the Stainlessbrewing 50 ft, 1/2" coil and the thing is awesome. Had a 25 ft 3/8 coil at first, and the heat transfer wasn't sufficient.

Not to hijack, but do you run your wort at full throttle through the coil? or do you slow it down?

 

[boondocksaint]

What is the height difference between the 14" and 15.5" coil?

According to the SB website the 14" dia coil is 7-8" in height. So, if it ended up on the high side, it's within an inch of what Kal offers.

My pots are 18" wide as well, so I appreciate the info. Hopefully Zach will get back to me soon!

I'm glad to hear how happy folks are with SB gear. Sounds like a solid company to deal with.

 

[turkeygecko]

Not to hijack, but do you run your wort at full throttle through the coil? or do you slow it down?

I start out very slow, and eventually increase to full throttle for MOST beers. Something low protein with no adjuncts, full throttle no problem. IPA's, lagers, RIS, whatever.

However, when I used lots of wheat, flaked corn, pumpkin, etc. I don't go full throttle, but still am able to maintain sufficient heat transfer. Had a pumpkin stuck mash and a saison with lots of flaked corn get stuck, so no full throttle for those going forward.

Also, I had the Steelhead pumps. A friend of mine has regular march pumps, and he says my pumps move WAY more volume than his. One of these days I am going to measure the oz. per minute my pumps move versus his. If what he says is true, and my pumps do move more volume, than I suppose I get a "full throttle" effect without my ball valves being wide open.

What about you?

 

[TechyDork]

I start out very slow, and eventually increase to full throttle for MOST beers. Something low protein with no adjuncts, full throttle no problem. IPA's, lagers, RIS, whatever.

However, when I used lots of wheat, flaked corn, pumpkin, etc. I don't go full throttle, but still am able to maintain sufficient heat transfer. Had a pumpkin stuck mash and a saison with lots of flaked corn get stuck, so no full throttle for those going forward.

Also, I had the Steelhead pumps. A friend of mine has regular march pumps, and he says my pumps move WAY more volume than his. One of these days I am going to measure the oz. per minute my pumps move versus his. If what he says is true, and my pumps do move more volume, than I suppose I get a "full throttle" effect without my ball valves being wide open.

What about you?

I have two SS Chugger pumps, and they move a pretty good amount of liquid at full open.

My last brew i ran the wort pump at full throttle, pushing through the coil, and i found that the ramp times were slower than i expected. I think the next brew I will try to throttle back on the flow of the wort and see what that does to my ramp times.

 

[turkeygecko]

I have two SS Chugger pumps, and they move a pretty good amount of liquid at full open.

My last brew i ran the wort pump at full throttle, pushing through the coil, and i found that the ramp times were slower than i expected. I think the next brew I will try to throttle back on the flow of the wort and see what that does to my ramp times.

Do you have a fast read thermometer? Just take the temperature of the wort coming back into the MLT from the HERMS coil. If that wort is at the temp of your HLT, slowing the flow won't help things along.