Heat Exchangers / Plate Chillers

I wanted to re-create a thread based on some difficulty I had with this very topic. I read quite a few threads with respect to the use of heat exchangers or plate chillers in home brewing, and it seemed like there were a lot of gaps in some of the information.

This isn’t designed to be a debate on the efficiency of heat exchangers vs counter flow chillers vs immersion chillers. It’s just what I found out from some very helpful friends and some people at Duda Diesel (this is not an advertisement either).

If you have something to add to this, or a correction in something I have miss-understood from them, by all means let me know by reply so I can edit the thread. I have simply put in here what I, and my colleagues have experienced as the average scenario of use.


• You want to chill as quickly as possible, but in reality it doesn’t need to be instantly. Commercially they are chilling huge amounts of wort and it may take an hour or more until the last drop is cooled down. In home brewing if you can chill your whole batch down in 10-15 minutes, that’s plenty fast. Some argue 20 minutes is acceptable. Try it yourself. Actual application on your own system vs armchair master-brewer theory are completely different ball games.

• More plates are not necessarily better. You’re looking for longer contact between the cold water and the hot wort so that they can equalize. A longer plate chiller is far superior to a shorter plate chiller in many ways. You’ll find that a 50 plate short heat exchanger will actually take almost twice as long as a 30 plate long one. It’s important to size correctly for your application and batch size. In an infinitely long plate chiller, the two fluid temperatures would match exactly, so we need to find a nice medium. Shorter and more plates allows for a higher PSI to be used. Longer allow for more efficency with lower PSI (like that of your garden hose).

• Water flow is the most important part of these heat exchangers. The more flow you have, the faster you can run your hot wort through to cool. The calculations done for most home brewer exchangers are based on a 5gal/min throughput. This is what you'll find as a flow rate on your exterior taps at your house. For my heat exchanger, it allows a flow rate of 2gal/min to exit at 70*F. If I were to use a pump and had a system that would support 10gal/min, I could then double the throughput of the wort. This is really a non issue because you can cool a 10gal batch in about 5 minutes on a $130 heat exchanger. Remember, your flow rate is not always 5gal, and in many cases its actually much lower. Throw a thermometer on the output of your heat exchanger and make the necessary adjustments of your pump output valve to limit the flow of your wort to achieve optimal pitch temp. If you're gravity fed, you can limit the output from the boil kettle valve.

• If you want to size, Duda Diesel has a chart you can measure your system out on to get the best possible result. Their charts assume a wort inlet temp of 212F, water inlet of 68F and a wort outlet 75F. They recommend a B3-23A as their high performance unit for home brewers. The 60 plate long version makes little performance gains (1 min saving) unless you're able to max out the water flow portion of the unit. For a home brewer, this would mean using your HLT as a water buffer and having a dedicated pump to flow more through the heat exchanger. Personally, not worth the hassle or the money.

• I want to minimize the amount of dicking around I do with my process so I sized so that I can go straight into the fermenter. I want to make my process as easy as possible, not more difficult. Some will aruge they like to re-circulate the wort back into the boil kettle, but I find this to be a pain in the ass and it takes too long. I sized my heat exchanger for pitchable output temp in one go and WP the boil kettle. Your mileage may varry.

• There are some things to do with hops and DMS and such with chilling times, but its more than I want to type here.

• A whirlpool will work just fine for these. Use a side pickup and skip the filter if you don’t have one. The units don’t clog up as easily as people suggest they might. You dont need to worry about your wort sitting around for an extra 5 minutes doing a hot whirlpool. (SankePankey reports problems with this so take this tip with a grain of salt)

• Heat exchangers are quite easy to clean with PBW. Percarbonate based cleaners are just fine for cleaning of copper and stainless steel. Do not use chlorine or bleach to clean your 300 series stainless steel equipment! Just re-circulate pbw cleaner through your heat exchanger (I do my whole system at once) for 30 minutes. Make sure to sanitize with boiling water or star-san prior to use. Some suggest you can bake these in an oven at 300 for an hour or two if it makes you feel more comfortable but I find a re-circ of my system works fine (and infact helps my March 809 pumps from getting sugar buildup). You may want to try sodium hydroxide to really clean out any gunk that might build up inside once in a while, but I'd suggest you read your ass off before using it. Consider yourself warned.

• Remember, a beer brewed on your system will be entirely different than a beer brewed on another system. This is not necessarily better or worse, it’s just different because of the setup of your equipment and the process you take. Just because my 30 plate long filter works for me, it does not mean a 40 plate short will not work for your process. I point this out because there are people out there that will claim “the way” and in reality, not even commercial systems are 100% every time.

• Find "you way" to make exceptional beer, be it kegs, pumps, blichmann pots or coolers. There is no "right way" no mater what people tell you. The journey to being a great home brewer is half the fun.

Good luck to everyone! I hope this helps someone else in their questions about heat exchangers.




Performance chart is linked below for sizing of heat exchangers. I do not know how they apply to other manufacturers as they are known to have different flow paths and efficiency.

http://www.dudadiesel.com/files/beerwortchart.pdf

Thanks to Duncan in Calgary and Bryan at DudaDiesel for the great help.

Actually, 2 small chillers will out perform one larger one.

Running the wort in series and the water in parallel.
Sometimes it's the simple things that escape us.

And quite overkill, but one way to do it none the less.

The units don’t clog up as easily as people suggest they might

Actually they clog up even more than most people suggest, it's just that the normal cleaning process doesn't get all of it out, it just pushes it deeper into the channels. The only real cleaning method is to filter it out to begin with.

I struggled with my Duda 30 plate chiller to get the performance that others claimed. I finally found peace with mine by doing a 15-20 minute steep/whirlpool at flameout so that my wort to be chilled was already down below 180F instead of trying to rapidly cool 210F wort.

insurgus said:

• A whirlpool will work just fine for these. Use a side pickup and skip the filter if you don’t have one. The units don’t clog up as easily as people suggest they might. You dont need to worry about your wort sitting around for an extra 5 minutes doing a hot whirlpool.

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I would like to refute this one, if you don't mind- and not from my armchair.

I do a recirculating plate chill with a dudadiesel 30 plate small. I knew that longer was better before purchase, but just couldn't fit a longer one in my 'patchbay'. I was hoping because of the recirculation, that this meant less time. I get 15 gallons from 212 to 70 in about 12 minutes and am still working on getting less time than that. I'm convinced that a recirculating chill isn't any (or much) faster per se than a gravity drain (armchair since I don't do that), it just gets the whole volume down rather than a portion.

It has been something other than just fine to master the pre-chiller filtering, in my kettle and post pump, necessary to avoid clogging. I use 100% pellets in a paint bag, have a 14 x 14 mesh screen before the bottom dump, and then a 20 x 20 mesh screen post pump. I am going to remove the 14 x 14 mesh pre pump cause that's the one that gets clogged the most and the one post pump I can service mid chill if I have to. The problem is compounded in that my kettle has a bottom drain, so I build a bazooka screen on copper arm type manifold to give it a tangential outlet on the side of the kettle.

The first time I used the chiller I wasn't hip to any filtering and clogged the chiller and had to bake it. After that point, I approached the problem from over-engineering it and am now lessening pre-filtering from there as I go. One thing that I will say is that most of the clogging problems come from the final gravity drain rather than the recirculation. All of the little particles bunch together that were previously in the full volume. I bet that a lot of this is due to cold break and not pellet matter.

After figuring this out, I can say that the cleaning post brew is as easy as mentioned. Way easier than taking a scrubby or brush to an immersion chiller that has hop oil all over it. My pre-filtering is so good (too good most times ) that zero particles come out of my chiller when I back flush. Another bonus is that I basically don't have to wash my yeast cause there is basically no trub in the fermenter. I've often wondered if that's a bad thing to filter that much, but I keep making beer!

insurgus said:

And quite overkill, but one way to do it none the less.

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Those are only 20 plate chillers.
Not overkill if you consider:
If the wort leaving the chiller is above pitch temperature it is normally sent back to the boil kettle. That means the wort is being re-heated, which counter-intuitive.

SankePankey said:

I would like to refute this one, if you don't mind- and not from my armchair.

I do a recirculating plate chill with a dudadiesel 30 plate small. I knew that longer was better before purchase, but just couldn't fit a longer one in my 'patchbay'. I was hoping because of the recirculation, that this meant less time. I get 15 gallons from 212 to 70 in about 12 minutes and am still working on getting less time than that. I'm convinced that a recirculating chill isn't any (or much) faster per se than a gravity drain (armchair since I don't do that), it just gets the whole volume down rather than a portion.

It has been something other than just fine to master the pre-chiller filtering, in my kettle and post pump, necessary to avoid clogging. I use 100% pellets in a paint bag, have a 14 x 14 mesh screen before the bottom dump, and then a 20 x 20 mesh screen post pump. I am going to remove the 14 x 14 mesh pre pump cause that's the one that gets clogged the most and the one post pump I can service mid chill if I have to. The problem is compounded in that my kettle has a bottom drain, so I build a bazooka screen on copper arm type manifold to give it a tangential outlet on the side of the kettle.

The first time I used the chiller I wasn't hip to any filtering and clogged the chiller and had to bake it. After that point, I approached the problem from over-engineering it and am now lessening pre-filtering from there as I go. One thing that I will say is that most of the clogging problems come from the final gravity drain rather than the recirculation. All of the little particles bunch together that were previously in the full volume. I bet that a lot of this is due to cold break and not pellet matter.

After figuring this out, I can say that the cleaning post brew is as easy as mentioned. Way easier than taking a scrubby or brush to an immersion chiller that has hop oil all over it. My pre-filtering is so good (too good most times ) that zero particles come out of my chiller when I back flush. Another bonus is that I basically don't have to wash my yeast cause there is basically no trub in the fermenter. I've often wondered if that's a bad thing to filter that much, but I keep making beer!

Click to expand...

12 minutes sounds about right for a short 30 plate. The longer ones make a huge difference in cooling time. If you could get your water flow up to 10gal/min you could bring it down to about 9 minutes.

I WP with a drill and an attachment that seems to clear things up pretty good. I haven't had a clog yet, but I'll modify the tip as per your experience.

insurgus said:

I haven't had a clog yet, but I'll modify the tip as per your experience.

Click to expand...

I don't want to scare anyone away from plates. If I had to do it again, I'd still have dumped my IC for the plate. I just think I would have opted for a larger plate and a gravity drain and mount my plate next to my wort pump.

The vast majority of folks here are not (daft enough to be) attempting a recirculating plate chill whereby you are basically going for an absolute filter pre chiller. I think I've only come across one poor soul who does on this forum.

My original thinking was that I was obsessed with getting the whole volume down below isomerization temps so as to do away with the idea of a hop back. Now I see that this is a little ridiculous. Pro beers have a 30 min whirlpool time and use a hop back for it's intended purpose - a filter medium ... and one that you throw away rather than have to clean.

The other thing about plate is that you will want to drain them by hand (just like your wort pump) or water will fester. I have mine mounted patchbay style above my HLT right next to water in and discharge out on quick disconnects, all connected to eachother with loc-line. So, many drips.... yet in this way they all go into the HLT which is super nice. But, the fact that at the end I have to take it off of it's mount to shake it by hand is a little counter intuitive. Luckily this is easier because I got the dudadiesel with back mounting studs and have them on thumb screws.

If I did it all over again, I'd have gotten a longer plate and mounted it in line with my pump and in line oxygen since all have to be hand drained at the end of brew day anyways.

EDIT: Oh, man that was a bunch of brain puke. Sorry bout that.

sankepankey can you go over your brew day starting from the end of the boil? I would like to whirlpool, plus recirculate through my plate chiller.

For the longest time I was giving my BK pump little more than a Starsan spray at the end of each brew session....a little water too, but not much. I'd hot water rinse the plate chiller and then fill with Starsan and put away.

One particular Saturday the pump just froze up (zero flow). I took the pump appart and was stunned to see the amount of buildup inside. Beer stone, etc. Cleaning was quick and the pump works fine now but it taught be a valuable lesson.

Now at the end of every brew session I run hot PBW (155F+) through the pumps and plate chiller for 20min. After that I run clean, hot water through for another 10min and then finish with 5min of a Saniclean circulation.

IMO - PBW or a home blend is the only way to clean the plate chillers. The hops and beer stone simply are too much for a simple boiling beer/water flush.
Hop spider, hop chute, or hopbacks are all worth using to reduce clogging risk.

ekjohns said:

sankepankey can you go over your brew day starting from the end of the boil? I would like to whirlpool, plus recirculate through my plate chiller.

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Good luck my friend. You are in for a bag of hurt regarding filtering. Completely insane if you don't use a hop spider/paint strainer or something like that. Now I am using biodiesel filter bags (same thing really) that give me a micron rating. I've got a 400 and a 250 micron. I think paint strainers are more like 600 micron.

After the boil, I am now letting the wort sit for at least 10 mins while I whirlpool and sanitize the line (pump, in-line ox, plate). Then I turn on the water and start chilling while whirlpooling. Then when I'm at pitching temp, I gravity drain into the fermenter. I've found that pumping into the fermenter can exacerbate any clogging issues that will prevent you getting all the wort out. Afterwords, I backflush and forward flush with hot PBW. Then rinse the plate and take it off the mount and shake it dry and let it sit on it's side so most of the water will drain to one side. All of the water never comes out and I can still hear it shaking around in there.

Gotta say that the plate chiller has not been easy to clean completely, for me, at least not as much as I thought it would be. I do flush forward and back with hot PBW and I still get little chunks that come out in subsequent flushings, despite my ample filtering. Hey, lets put it this way. Real professional breweries who's batches are worth thousands of dollars do not use a brazed plate chiller. They all (conjecture) use a plate chiller whos plates can be dismantled after the cycle and thoroughly washed. The little creases in a brazed heat exchanger are perfect for trapping teeny hop particles and flushing sometimes doesn't get them all out. If you don't brew the very next day, then they will contaminate. If they are heat sanitized, does that takes care of it all? I guess so, but you're talking to someone who's battled with contamination recently, so .... no comment. I'm off to bake my plate chiller for 2 or 3 hours... I don't know if it's from my plate or from a bad weld in my fermenter (very possible) that I can't fully sanitize. So, not the most positive person in the world right now regarding plate chillers.

Thanks spankepankey. I have already incorporated a hop spider into by brewing so that is no problem. I will look into hot whirlpooling, but what i have read so far is it may cause DMS. Do you agree? Do you think it would be better to hot whirlpool without the plate chiller attached, then drain via gravity through a starsans cleaned plate chiller. This should significantly limit the amount of turb going through the PC.

That's why I put the return line (loc-line) under the wort level and not splashing into it. But I have seen videos of breweries that pump and splash hot wort into fermenters (cool ships) with no concern for hot side aeration (HSA) - which is what I think you're really talking about. DMS will get scrubbed out by a proper fermentation. Breweries have hot whirlpool times that far exceed a homebrewers with no issues. If you've boiled vigorously, you won't have a DMS problem. This is the understanding I have at least.

cool, I will have to give that a try (assuming I get my birthday brew gifts). I am not too concerned about cold break in the fermenter, I would like to avoid it but if it comes down to no cold break but clogging dirty PC vs. cold break with significantly less problems, I will choose that route.

I don't have issues with cold break (well the proteins and such). I have hop pellet matter issues. Cold break in the fermenter is supposed to be good for the yeast and I've hear excessive filtering of it actually makes fermentation suffer (making the beer lack luster) because there are no nucleation sites for the yeast to grab onto. I don't know if my beers suffer from this or not. All I can say is my yeast comes out without any need of rinsing. It's darned purdy as is.