Boil kettle condenser - no overhead ventilation needed

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Hi HBT,



One of the major benefits with electric brewing is the ability to do it indoors, and many have proven this by building sweet brew rooms. One of the major headaches with doing so, however, is the need to exhaust the steam, otherwise end up with a hot moist brew room. Electric brewing pioneers like Kal came up with an overhead ventilation system consisting of a hood and fan which generally work well. When implemented right, a ventilation system both exhausts steam and replaces that air from outside so the HVAC system doesn't suffer by venting conditioned air from the house. Californians of course, need not apply, as they have perfect temps inside and out!



Personally, I brew in my garage, but do so often at night, and an open garage door welcomes mosquitoes and other bugs to come in and torture me. When I close the door, the garage becomes a steam room, so I wanted to find a solution, and this is one which could work for all indoor home brewers.



Borrowing a page from some industrial users and some of the pro brewing systems, I created a home brew version of a simple steam condenser to reduce (or eliminate) steam escaping the boil kettle. I did an experiment, which I believe proved successful, indicating this may be practical for brewers to use instead of overhead ventilation. The concept is shown here:





The idea is that ambient temp water sprayed into a chamber where steam exists will cool the steam and cause it to phase change back to liquid. In doing so, the steam's volume contracts about 1500x, in turn creating a local area of vacuum, pulling in more steam and continuing the cycle.



The home brew design is straightforward, using a simple water sprayer inside a tee. The tee is mounted upright to the side of the kettle so the lid can be used as normal. In my experiment, I used a 2" tri-clamp tee, mounted to a solder-on flange. At the top of the tee is a cap where the sprayer is mounted and the water fed through. At the bottom is a nipple which allows for a drain tube to be connected. The water that is sprayed into the tube plus the condensed steam exit through the drain tube.



This sprayer I used is ~6 gph at 40 psi, so a little less at my house pressure's 30 psi. I actually bought the sprayer before doing the math, which determined that a 1.25 gal/hour boil-off with a ~80 degree F spray temp needs about 7.5 gph. So I will be upgrading to a 9 gph sprayer. In my use, I will just drain this water, which will be very hot and contain the boiled off contaminants. I am comfortable "wasting" ~10 gallons of water over a 60 minute boil as I live in FL, but those who aren't could certainly capture the water and re-purpose it.



Here is the 2" hole I drilled in the side of the kettle. I would have preferred to put it as close to the top as possible, but my cheap Bayou has a flange around the perimeter, normally used to support the steamer basket. I used a clamp to hold the TC flange in place for the experiment, but it will be soldered on soon.

View attachment IMG_1760.jpg



Here is the assembly. The water feed goes through a 1/4" OD panel mount tube fitting which is mounted in a TC cap.


View attachment IMG_1758.jpg


Here is the sprayer assembly. For the test I used PE tubing inside, but only after realizing that push to connect tube fittings will not grip stainless tube. This tube will be replaced by a proper tube rated for temp. The sprayer tip ends upjust above the T port, capturing the steam coming in quickly.

View attachment IMG_1761.jpg



Here is the video. I used plastic wrap so I could seal around the clamp and see what was going on inside (kind of). Note the plastic wrap expanding and contracting with pressure changes as the sprayer is cycled off and on. I could not seal the area through the clamp perfectly, but I think this proves the point. Also, ignore my stoopid voice, but listen to the vacuum sound the sprayer makes (on its own it is silent).


[url]https://youtu.be/rw-uHIF8j64[/URL]


Here is my celebration beer (Caribou Slobber clone-ish). Excuse the glass - was trying to limit how much I downed.

View attachment IMG_1762.jpg



The only question that really remains for me is if this will not hinder boil performance, meaning specifically, will the volatiles which are boiled off (DMS, etc.) be properly evacuated from the beer. Some liquid will condense on the kettle lid which will be left on during the boil, dripping back into the beer, but I dont suspect this to be a problem as it works in pro boilers. But more testing will tell.
 

schematix

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This sprayer I used is ~6 gpm at 40 psi, so a little less at my house pressure's 30 psi. I actually bought the sprayer before doing the math, which determined that a 1.25 gal/hour boil-off with a ~80 degree F spray temp needs about 7.5 gpm. So I will be upgrading to a 9 gpm sprayer. In my use, I will just drain this water, which will be very hot and contain the boiled off contaminants. I am comfortable "wasting" ~10 gallons of water over a 60 minute boil as I live in FL, but those who aren't could certainly capture the water and re-purpose it.
First, kudos to you for venturing out and trying something new! This is a very real problem, and one that doesn't have a really elegant solution. This seems like it may have some potential.

For your sprayers, did you mean gph, not gpm?
 

JONNYROTTEN

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What about heat? I tried covering my pot with the lid once and almost instantly had a foamy boil over with 6" of head room. Lid off and it was just a rolling boil. Would this bypass that issue by design?

I need a steam solution as I brew in my kitchen and will be following
 
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What about heat? I tried covering my pot with the lid once and almost instantly had a foamy boil over with 6" of head room. Lid off and it was just a rolling boil. Would this bypass that issue by design?

I need a steam solution as I brew in my kitchen and will be following
The heat is pulled out by converting steam back to water. It makes the water going out the drain very hot! In my case, that will be down the driveway. But it could go down the sink, or into buckets. Another variation of this system would be a closed loop condenser (in fact another user has done this successfully). Closed loop would use a copper coil with recirculating water inside, and that water would be cooled via an air-water radiator. Closed loop would not waste any water, but the the heat would need to be rejected somehow.

One other benefit I forgot to mention is that in case of boil-over, this *may* help prevent it, as the foam could get sucked down into the drain. I personally use fermcap religiously. That plus an automated ramp means I never even get close. But this could provide a level of backup.
 

Stealthcruiser

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I'm diggin' the idea, though I'd probably never need it.

One suggestion, that you might incorporate into your " T " assembly on the side of your kettle, and may increase the efficiency of, cut down on water usage, ( allow ambient air temps to assist the phase change).

Should be worth an experimental run, and would require both ends of the T to be open.

https://en.wikipedia.org/wiki/Venturi_effect
 
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I had initially considered a large diameter vent tube than turned down (just an elbow) and had a venturi in the duct. The venturi would effectively create or assist the vacuum, and the introduced air would create the phase change. Then hot water would exit the tube/drain. This would likely work, needing an air pump with decent volume. I tried to find an "off the shelf" venturi for a 2" or 3" duct but could not find one at reasonable cost (though I was close to doing this: https://flexpvc.com/cart/agora.cgi?p=PVC-Venturi-Tees&xm=on). The exhaust would be hot water (converted steam only) and hot air (though saturated, so humid). So in this configuration, the heat and moisture would need be vented somehow - this defeats the purpose for the indoor brewer. So, I went with the sprayer design, which carries all the heat and moisture away. Overall, this was probably ~$100 in parts.
 

paledragon

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This could be a great solution for me. I brew in my basement, which can vary from 45-70F throughout the year. I've tried the hood/duct fan approach, and it's just not ideal, especially in the winter. I was about to try a direct venting approach similar to ClaudiusB, but all that piping adds up! I might have to give this a whirl as well...

p.d.
 

mabrungard

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What about heat? I tried covering my pot with the lid once and almost instantly had a foamy boil over with 6" of head room. Lid off and it was just a rolling boil.
Remember, as soon as you put the lid on the kettle, the heat loss through evaporation and steam escape is significantly reduced. You have to reduce the heat input to reestablish a proper energy equilibrium when you put on the lid.

Wow! Brundog, this is a very interesting idea. Good research and implementation.
 
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Thanks Martin. Yes, I agree... the heat input needs to be figured out as it will be different. That said I don't think it will be much different than having the lid off. I was running the sprayer right before the boil, and the boil took longer than I expected to get going, so I think this pumped out the pre-boil steam and heat fairly well.
 

TorMag

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Just look at my avatar, that's me trying to figure this whole thing out. Looks cool, but above my pay grade, but something I need as I brew in my basement. A nice, step by step, build thread would help me out......
 

Wizard_of_Frobozz

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Nice experiment Brundog! I am following with great interest, since the eastern shore of Maryland is very humid in the summer.

Make sure you do a brew with a lot of pale lager malt to see how the DMS reduction is with your kettle covered like that. That would be my biggest concern.

I do have a question (of course I do - when do I not ask you questions? ;) )

What about a hybrid system with an exhaust hood, but put the exhaust through your condensing unit instead of venting it outside? That would solve the issue of needing any make up air and still keep the top of your kettle open. It would make hop additions easier at any rate.
 
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Haha, I get nervous when you ask questions - it usually means I missed something!

I modeled this off pro brew kettles, which don't necessarily need make up air. When water phase changes it increases in volume ~1500x. That creates volume which the condenser in turn removes. So in *theory*, there is no additional air needed. In *practice*... I can't tell you just yet.

The problem with hoods is they don't capture all the steam. I think this thread, which is the only prior home brew experience I could find, did it this way: https://www.homebrewtalk.com/showthread.php?t=297089. I think that somewhat defeats the simplicity of this system though (extra hardware, etc.), though I don't see any reason it couldn't be done this way. Yes, hop/adjunct additions need the lid to be briefly removed, but that's seconds compared to the hour/90 minute boil time. Of course, an automated hop/adjunct dispenser could be employed... Next project!!
 

Wizard_of_Frobozz

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Well I appreciate you putting up with all my questions!

I agree with the concept - seems very sound. In that other thread, this idea was discounted due to the “waste” of water but water isn’t ever wasted really. It just goes back into the water cycle; maybe more processing will be done by your local water utility but the water isn’t destroyed. I’ll bet homebrewers use far more water chilling that your condenser does!

DMS reduction seems like the biggest risk with this. Get brewing a pale lager!
 
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Yes, I agree... if the water goes down the sink, it gets reprocessed by the city if you are on city sewer. I brew in my garage so it goes down the driveway, but I suppose I could capture it in buckets and water my lawn. You are right... the ugly truth the counterflow chiller wastes more water!

I agree on DMS too - that is my concern, though I believe it will get flushed if it is carried in the steam. Time will tell!
 

paledragon

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I read, somewhere, you can taste the condensate for DMS and other boil off nasties, and that eventually the taste will go away toward the end of the boil if you taste test the condensate.

Another option, for beer styles more sensitive to the presence of DMS, is to boil longer (e.g. 90 minutes).

P.d.
 

Bilsch

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Yessir. In fact I have this one: https://www.mcmaster.com/#3178k46/=19so93t. But I will likely upgrade to the higher flow unit. Its ~3 more gallons of H2O used, but meets the need per the math.
Really cool idea you have here and have been reading with interest. I wanted to mention something about this nozzle you might find interesting. Instead of getting a larger flow, maybe you could think about increasing the pressure. I'm thinking you could use less water if the droplets were much finer. I use almost the same McMaster nozzle, the no-drip misting nozzle, for misting in an industrial application. We found it really starts to work better and atomizes more efficiently when you approach 100 psi or more. To get these higher pressures over water were using a pressure vessel, very similar to a cornelius keg, and just air it up using a regular air compressor. I would think if you have a spare corny this might fit the bill for your application as well.
 
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Good points @paledragon!

I agree @Bilsch that more pressure equals more better. I have a water hookup to my rig, which feeds the water for the chiller and cleaning, so it is just easy to use that for experimentation, but no doubt higher pressure would increase atomization, velocity, and volume. I brew once or twice a month, so ~6 extra gallons wont mean much. Heck, my kids leave the shower running for 30 minutes before they get in it - that is a real problem to solve!

That said, it really wouldn't take much to add something like this: https://www.amazon.com/gp/product/B01N75ZIXF. Since the volume is way less, this pump could easily generate 80+ psi. For $20, it might be a worthwhile test. Thanks for the idea - maybe I will give this a try after I get live brew tests done.
 
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mabrungard

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After most of the SMM (DMS precursor) is converted in the wort, it is possible to rid all the DMS from your wort in a few minutes of additional boiling and venting. Most SMM is converted in about a half hour at sea level, but the conversion rate slows with higher elevation and the lower boiling point. DMS boils at body temperature (98F) and our typical kettle temps are more than enough to get it out of the wort. A nice, active boil with a more open venting to the atmosphere is highly likely to expel all DMS from the wort. I open my kettle for the last 10 minutes for that purpose.
 

Mountainsax

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As always Brundog, your ideas are excellent and thought provoking!! I’ll be interested to see how the beer turns out and if DMS is an issue. Should be pretty easy to find a good use for the water so it’s not wasted. Collect it, add some PBW and use it for cleaning up!
 

thekraken

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After most of the SMM (DMS precursor) is converted in the wort, it is possible to rid all the DMS from your wort in a few minutes of additional boiling and venting. Most SMM is converted in about a half hour at sea level, but the conversion rate slows with higher elevation and the lower boiling point. DMS boils at body temperature (98F) and our typical kettle temps are more than enough to get it out of the wort. A nice, active boil with a more open venting to the atmosphere is highly likely to expel all DMS from the wort. I open my kettle for the last 10 minutes for that purpose.
I remember a few months ago that you were experimenting with just a cracked lid during a boil, about an inch or so. What's your procedure now?
 

TheLostBeer

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Wonder if you could go the same idea for distilling, making a hood that is slightly larger then the Brew kettle, then get some pipe to connect to that hood then connect a immersion chiller and modify it to allow the water to flow out when it condenses and get something to catch it so you can reuse it for whichever you choose.
Cause also use a bucket with water and put the immersion chiller in it to help it condense faster.

That’s just off the top of my head anyway, working off the same idea as distilling.

But like what your doin here brundog!
 
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Ya there’s multiple different ways to condense steam. In theory it’s right above boiling temp but there is a crap ton of energy in it to pull out to induce the phase change back to liquid. That heat will pile up fast. In this system, that heat is basically washed away. Normally we just dump it to the atmosphere.

Update: since my BK has multiple connections (bottom drain with electric valve, pressure sensor, non-detachable element housing) it is a bit of a PITA to remove it to lay it on its side for soldering the TC flange. Not only that, the flange’s radius is a little big for my kettle, so the center touches but the edges don’t. Bobby says this isn’t a problem, and I trust him, but I have been concerned about the non-flush gap. Because this is a dump system and the flange is mounted “outside” the kettle, I considered bonding it on with epoxy. Well, to my pleasant surprise, this JB weld suits the job AND has an NSF seal. So I feel pretty safe bonding it on with this. It’s also temp rated to 300 degrees. Anyone have any concerns about this? It’s not my style to do things half-arsed but this kettle will likely be replaced in the not-too-distant future.

View attachment IMG_1776.jpg
 

Wizard_of_Frobozz

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Update: since my BK has multiple connections (bottom drain with electric valve, pressure sensor, non-detachable element housing) it is a bit of a PITA to remove it to lay it on its side for soldering the TC flange. Not only that, the flange’s radius is a little big for my kettle, so the center touches but the edges don’t. Bobby says this isn’t a problem, and I trust him, but I have been concerned about the non-flush gap. Because this is a dump system and the flange is mounted “outside” the kettle, I considered bonding it on with epoxy. Well, to my pleasant surprise, this JB weld suits the job AND has an NSF seal. So I feel pretty safe bonding it on with this. It’s also temp rated to 300 degrees. Anyone have any concerns about this? It’s not my style to do things half-arsed but this kettle will likely be replaced in the not-too-distant future.
I used JB Weld to attach the electrical box to the bottom of my e-HLT. It's a weird conical bottomed vessel that I repurposed from work. The conical section is about 1/8" thick and curved, which made a weldless fitting impossible to work - I couldn't get the locknut around the heating element threads with anything more than the gasket on the element. My solution was a gang box extension with JB weld attaching it directly to the vessel. It's been over 10 years and no issues but the HLT never goes above 170F, so I can't say for sure if 212F will cause any issues but I doubt it since JB Weld is rated for much higher temperature.

I've been thinking about your setup; it seems like one important aspect is the have the kettle top sealed fairly well to ensure the steam goes into your condenser. You also want it to be easy to open for hop additions. I'm struggling with this - can't seem to come up with a good solution. What are you thinking for sealing the kettle top in the long run? The plastic wrap doesn't seem like a permanent solution.
 

mabrungard

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I remember a few months ago that you were experimenting with just a cracked lid during a boil, about an inch or so. What's your procedure now?
It is my SOP now. It does work and I haven't found a negative from the method. Based on the research I've done on DMS, the more open boiling phase at the end of the boil is a good method for expelling the final DMS in the wort.
 
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I used JB Weld to attach the electrical box to the bottom of my e-HLT. It's a weird conical bottomed vessel that I repurposed from work. The conical section is about 1/8" thick and curved, which made a weldless fitting impossible to work - I couldn't get the locknut around the heating element threads with anything more than the gasket on the element. My solution was a gang box extension with JB weld attaching it directly to the vessel. It's been over 10 years and no issues but the HLT never goes above 170F, so I can't say for sure if 212F will cause any issues but I doubt it since JB Weld is rated for much higher temperature.

I've been thinking about your setup; it seems like one important aspect is the have the kettle top sealed fairly well to ensure the steam goes into your condenser. You also want it to be easy to open for hop additions. I'm struggling with this - can't seem to come up with a good solution. What are you thinking for sealing the kettle top in the long run? The plastic wrap doesn't seem like a permanent solution.
I will be using the kettle lid - the plastic wrap was just for testing so I could "see" what was happening and seal it off. Of course I couldn't see anything anyway.

I don't think the lid will be a problem alone. If the condenser creates the appropriate vacuum, there will be little incentive for the steam to escape. I will know more once I bond the flange and run another test with the lid on. Even if a little steam escapes, I don't think that will be an issue. The key is to knock out most of the steam/heat.
 

Wizard_of_Frobozz

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I'll be interested in hearing the results. I had visions of a complicated lid with hop access door like the pro's use!

Also, here's a picture of my HLT electrical box with JB Weld. Not pretty but it works.

IMG_0797.jpg
 
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Ok the bonding seems to have worked well. I did another experiment and learned some things. Moral of the story... math works!

When I fan flat out with 100% duty on the element, the steam overwhelmed the system (currently has the ~6gph sprayer). The temp of the water exiting was at 211, and there was steam escaping through the lid.

Once I lowered the boil to a more normal rate, the system caught up and the flush water temp came down to a more normal ~150 degrees, and there was no steam escaping the lid.

I need to do a legitimate brew before I claim success, but it’s looking like it will be. Interestingly, for those super water conscious, you could automate the water flow rate with a proportional valve (very small Cv range), using the flush exit temperature for guidance. I am probably going to upgrade to the 9 gph and call it a day, but it’s an option. Also interestingly, one minor downside of this system is that it does work passively. Some of the steam prior to full boil leaks out the drain with the sprayer off, so it slows the boil achievement down slightly. A trap in the drain line would reduce this effect.

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Wizard_of_Frobozz

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Hurry up on that "legitimate" brew! I'm about 50% complete on framing in my new brew room - sure would be nice to know I don't need to bother framing in an exhaust hood!



Great work Brundog!

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augiedoggy

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Just a heads up with the jbweld. Ive seen it used on engine blocks with success so I believe the temps are good to at least 200 but jb weld claims its good for constant temps of up to 500F!
It is food safe and I use it to seal the ends of my stainless thermowells in my conicals.
 
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Thanks. I used the SteelStik which is temp rated for 300. It has the NSF seal so should be food safe, though it’s technically not in the beer path.

One thing for certain is that stuff set up quick!
 

Wizard_of_Frobozz

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Whoa! Give us more details on that sweet space!
It's in the back corner of my pole barn. The large bay holds my camper; the brew room will sit behind my truck. I had a plumber run drains for the sinks, toilet, floor drain, and RV, plus the water supply before the floor was poured. Once framing is done, i'll be running 50 amp over to the room and the RV outlet. I'm just now starting to make some real progress on the room - it's been way too hot and humid to get much done over the summer! My hope is to be complete around January, but knowing how much real life seems to interfere, it will likely be a bit later than that...once I'm done, then I will post a build thread for it. :rockin:

Barn Layout.JPG
 
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