Coil or Pump herms HELP!

[BadWolfBrewing]

The first brewing on a new system is under way. Stout tanks, electric, herms.

Experiencing a problem. The HERMS coil that stout includes in their HLT is sort of insufficient. I would guess it is maybe 30' of slightly under 3/8" stainless. The wort coming out of the coil is less than the temp of the HLT, which makes controlling temperatures tricky.

My options to fix are either a higher flow pump (I have chugger center inlets), such as the march AC-3B-MD or a better coil. A better coil will increase the heat transfer into the coil, while a pump would just increase the flow rate. Right now, I'm maxing out at about 1.3 gpm, which might be an upper limit for grain bed compaction.

I'm leaning towards a coil, mounted to the lid. All vessels share the same lid, so I have 3. A 50' 1/2" coil mounted to the lid could double as a chiller, when put on the brew pot, so that has a nice ring to it. A higher flow pump would make for more effective whirl-pooling, which is also nice. That being said, the flow through the chugger center inlet is pretty impressive, without the restriction of the coil.

I haven't insulated the MLT, and that would help some. I'd prefer not to, for pure aesthetics...

Am I missing any perspectives?

Many thanks

 

[kickflip_mj]

What size are your tanks? Maybe slow the pump down?

 

[BadWolfBrewing]

20 g. Slowing the pump down made it worse, i.e., slowing the rate of heat transfer to the MLT.

 

[kickflip_mj]

I feel like 30' of 3/8ths is inadequate. I'm building my system with 25 gallon tanks with 50' of 1/2. Maybe get a cool from stainless brewing and make a jokey box with the other coil?

 

[BadWolfBrewing]

thats the front running idea. Cheaper than a pump upgrade, easy to mount through the lid. I had a countertop brutus style before where I did that, it worked really well as a dual purpose HERMS / chiller. I have no idea how that stainlessbrewing guy makes a profit...

Jockeybox = awesome idea

 

[kickflip_mj]

thats the front running idea. Cheaper than a pump upgrade, easy to mount through the lid. I had a countertop brutus style before where I did that, it worked really well as a dual purpose HERMS / chiller. I have no idea how that stainlessbrewing guy makes a profit... Jockeybox = awesome idea

How is the coil mounted? Is it welded through the tank wall? I have heard stout tanks will definitely work with you to figure the problem out. I have spoken on the phone with stainless brewing and they buy massive rolls of tubing at a time. I think in large spools by the thousands of feet.

 

[BadWolfBrewing]

the coil is welded onto TC end caps, and the tank wall has bulkheads with TC fittings on both ends. So, the coil is removable. A coil that would match these fittings would be great, but it would be tough to do, the alignment would have to be absolutely perfect.

I thought about emailing them, though I'm not sure if they would be interested in helping. Perhaps they'll change their design for future products at least

 

[kickflip_mj]

It's worth a shot, they may even be able to make you a larger coil at a discounted rate?

 

[BadWolfBrewing]

I've emailed stout, we'll see what they say. I tried to not sound too vindictive, but while making it clear I was disappointed. The HERMS is a $160 upgrade, so I think disappointment is reasonable.

-- start letter

I just brewed the first batch on a new brewery. 20g MLT, HLT, and boil kettle,with electric ports in the HLT and boil kettle. For the most part, it all went very well, aside from a HERMS issue.

The HERMS coil is too short and narrow to get enough heat transfer from the HLT to the MLT. I measure about 30' of 8mm tube in the coil. I am recirculating at a little over 1 gpm, which is about as high as possible before grain bed compaction may occur.

In a previous smaller brewery, the temperature in the MLT and HLT would be nearly identical, making control very simple. With the 20g stout tanks system, there would be a 5 - 10 degree F difference, steady-state. While insulating the MLT would help some, others have succeeded in controlling the MLT temperature without taking this step.

I believe a larger diameter coil made from a larger diameter tube would alleviate this problem, based on anecdotal evidence of other brewing systems (which is why 50' of 1/2" tubing is fairly standard in DIY builds). A 10" diameter coil of 1/2" (about 10-12" coil height) would fit in the pot without interfering with the element or temperature probe.

Does your factory have the ability to create coils that might work better for homebrewers? I wouldn't mind chipping in for a better coil, but to be honest I'm sort of disappointed in the $160 upgrade that does not perform as I had hoped. If your factory doesn't have this ability, I will have to contract out to have a coil built to my specifications, and install it through the lid. It takes away from the 'off-the-shelf' brewing system concept though.

Thanks for your help, sorry to complain

Chris


-- end letter

I'll post the response when I get it.

--edit, the upgrade was $220, as it was a special coil to fit an HLT with a heating element

 

[Roadie]

Chris - did you ever receive a response?

 

[BadWolfBrewing]

Yep, we exchanged a few emails talking about coil sizes.

I kept the same coil (for now), but I did find a way to make a difference. The HERMS coil is pretty tightly coiled, and so the recirculation in the HLT wasn't really doing it's job, despite the fact that I was around 12 gpm. The volume of hot liquor 'inside' the diameter of the coil wasn't getting recirculated much at all, and so it was much cooler than the volume of hot liquor 'outside' the coil.

To fix, I added a tee on the inside of the recirculation port of the HLT. Some of the return liquor get shot down the side of the kettle, and some gets shot down the center of the coil. This made a pretty large difference.

If I leave all lids on, I can get the MLT to track the HLT within 1 - 1.5 degs F. Due to the limited flow rate possible (tiny herms tubing), it still takes a LONG time for the MLT to respond to the HLT, but that isn't a huge deal for now.

There's another guy ordering a custom coil to replace the stout-tanks coil, I'm still waiting to see how the new coil does

 

[sandyeggoxj]

I am interested in this as well. I have a 30-gallon e-herms system on order from stout. I guess I could go rims if it doesn't work but that would be an expensive change at this point...

 

[WhiskeySix]

I had a similar problem with my homemade HERMS. I did something similar as well. I opened up the coils and added a whirlpool fitting so that I now recirc and whirlpool the water in my HLT. I have two Chugger center inlets so it works great. Mash recirc through one and HLT through the other.