Fishies to Fermenting; aquarium chiller fermenter

Moved to Florida and have been dumb founded by the heat... Haven't brewed since last March because of the heat.

So, after inheriting an aquarium chiller and some aquarium pumps--I searched this forum and grabbed some ideas to put this stuff to use. The project came together surprisingly well with mostly stuff already around the house!

An old cabinet that I had made and insulated for the conical a while back, an rv pump, etc...

Not sure if this is the best setup--but brewed a wit beer yesterday--and the setup certainly works as is.

With a standard immersion chiller I got a 12 gallon batch down to 80F. The bath of r/o water (about 10 gallons) in the cooler was chilled from room temp to 42F in a few hours with the 1/10 hp aquarium chiller. Within a hour of circulating the bath water through the immersion chiller in the fermenter--the wort got down to 62F and the cooler water increased to 52F.

Curious if anyone has any thoughts on improvement. Take a look, and after the pictures, I will comment on my concerns.















easy to sanitize...







Project manager: "Brewer" the dog.

concerns:

Condensation: The plumping creates some condensation. The fermenter doesn't "sweat" (at 62F anyway) but the hoses coming from the chiller to cooler and the hoses coming from the cooler to the fermenter(s) do. They drip a wee bit. With electrical stuff in there--I am not a huge fan of that.

Will insulating those lines fix that? Anyone know of source of removable hose insulation, if so?

With the conical I wanted to try a lager. I figure that will "sweat" condensation at lagering temperatures. Anyone lager in MoreBeer conicals? Do they sweat--or does the insulation prevent that? Any sources for such insulation? Maybe just a sanke keg sweater?

Anyone know of sources of insulating tubing in the 3/8"- 1/2" size range? Maybe that would be an easy fix for the sweating tubing?

Insulating cold lines is always a good thing, from both condensation and efficiency viewpoints. Indeed I'd insulate both sides of the cooling loop between the chiller and the conical. If you can't easily find suitably sized foam "tubing" you can just roll sheets of foam around the lines, tape them in place, then cover them with a foil sheath to keep moisture-ladened air from soaking the foam.

btw, I'm feeling sorry for that chiller, having to live in its own exhaust heat in an unventilated and insulated space. Poor thing ain't gonna last long like that...

Cheers!

I second moving the chiller out into the open.

You should be able to find pipe insulation at any big box store or local hardware store.

If your chamber is sealed the fermenter shouldn't sweat much.

jtsims21 said:

I second moving the chiller out into the open.

You should be able to find pipe insulation at any big box store or local hardware store.

If your chamber is sealed the fermenter shouldn't sweat much.

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Thanks for the answer on the coolant lines...

As for the chiller

There is no right side of the cabinet (it is open to the room for ventilation)... There are also two fans (see pictures above) venting air out that side... That should be plenty of ventilation I would think... Feels cooler in the box than in the room with the fans...

The project manager demanded a run at the beach and on the way we stopped by the Home Depot. Found some cheap insulation for the coolant lines. Cleaned up the electrical wires a bit too...

Gotta say this chiller rocks...

The wit is going crazy fermenting and it takes about 2 or 3 minutes per degree to drop the temperature. Have the Ranco controller set at 62F and dropped it 60F just to see if it would. The pump kicks on and 12 gallons of active ferment dropped two degrees in a little over 5 minutes. The coolant bath went from 45F to 46.5F.

Thinking I might be able to crash cool pretty dang quick. Definitely not the most attractive system--but works really well!

Some pics:

That is a pretty cool, but all that equipment seems so expensive and bulky, why not just get a used fridge and slap one of those controllers on it and call it a day?

That said, creative use of tools.

edecambra said:

That is a pretty cool, but all that equipment seems so expensive and bulky, why not just get a used fridge and slap one of those controllers on it and call it a day?

That said, creative use of tools.

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Two words: The wife.

Buying a new fridge was a no go. This was the least expensive route because most of the stuff I had on hand already.

The chiller and the pumps came from family that tore down a fish tank (free). Figured I could find a use so grabbed them when offered... The r/v pump came from an old r/v (free). The igloo cooler was our beer cooler that never got much use (I know--sad--but we have another one).

We use to live in Alaska (believe me cooling anything up there is not a problem!) and the Ranco controllers and the insulated box was set up for heating rather than cooling (it use to stand upright) up there. I wanted to use the box somehow. On its side works pretty well for this.

The brew pot was a birthday present, but I have converted keg kettles to brew with... However, the present worked out though--because I actually prefer to ferment in that more than the conical!

Way easier to clean up the kettle v.s. the conical (less parts) and easier to move around. The best part is I just boil a gallon of water in it on brew day to sanitize--steam sanitized in 10 minutes from when the flame goes on. Pretty slick for fermenter if you ask me. A tight seal on the top is totally unnecessary for primary fermenters--and the kettle stainless throughout--for way less than a conical. Stainless ladle = yeast harvest.

The kettle thermowell came with my converted keg kettles purchased years ago, but they suck for mashing--too slow to heat up and cool down--so I never used them.

I did have to purchase the stainless coils but cheap at New York Homebrew or something like that. The wife let me get those.

Also--I'll have to check the electric usage--but I am thinking this may be cheaper on the electric bills than converted fridge or freezer. Maybe I am wrong there--but the wit is going crazy and the chiller runs for only about 30 minutes every few hours to cool the bath water back down a couple degrees from the set point. The chiller is set at 45F and I could probably set it at more like 50F or so--to reduce it from cycling even more.

In contrast--my guess from experience--is that fridge or freezer set up with a controller--with 10-25 gallons of fermenting beer would be running 24/7 to keep that much fermenting beer at 62F. Cold air around fermenters just is not efficient at all. Stainless fermenters insulate the beer from the cold air too well. Buckets are the same. So is glass.

For our wedding--I had six, 6-gallon-buckets in large chest freezer making a butt ton of lager--that freezer never shutoff for two weeks and struggled to get the lager to 50F. Whole different story cooling 20-30 gallons v.s. 5-10 gallons of actively fermenting beer in a converted fridge or freezing.

So far this chiller has barely run to keep 12 gallons of ale at 62F. My guess is it will be pretty rocking for lagers. Especially if I insulated the fermenters to some degree. Maybe just put keg blanket over them.

I think your personal past experiences are leading you to incorrect assumptions. A chest freezer should have had no problems keeping up with 30+ gallons of lager, or ale for that matter. If you experience things that seem to fly in the face of conventional wisdom, it isn't likely that basic thermodynamic laws have changed. It is more likely that something else was going on.

If you had a jacketed and insulated conical, that aquarium chiller would be ideal. Since you don't, you simplest solution is to get a free or cheap (<$50) fridge off of craig's list, and put the conical in that. You may end up spending more on using the aq. chiller than getting a used fridge, especially if it is free. Controlling to the ferm temp (probe on/in the conical), rather than air temp, is the best way. If the probe is 'in' the wort, it should be near the conical wall to prevent overshoot and radial stratification. Placing the probe on the wall, then some insulation over it works best.

To make effective use of the aq. chiller/immersion chiller for ferm'ing, you would need to insulate the exterior of whatever ferm vessel you use. That may be more of a hassle than using a fridge, but is a personal choice. At 1/10 HP, your aq. chiller only has 1/2-1/4 the chilling power of an avg. fridge/freezer. It chills directly when using an immersion coil, so it balances, to some extent, the lower power.

For chilling wort to pitching temps in places with warm tap water, using city water until the wort is ~100F, then switching to an open recirc'ing ice bath is going to be more effective. Agitating the wort during chilling is critical to reduce chilling time. You could use the aq. chiller to get the cooler full of water cold, then use that for the final chill, but using the electricity to make ice instead would be a better overall solution.

There is nothing wrong with making do with free equipment, but you need to use it correctly and understand it. The are ways to improve you current setup, but I didn't want to get into it since the alternative seems so much easier to me.

One thing to consider with your semi-open fermenter. Once the active ferm stops, you will lose the CO2 blanket. The rate of loss will be related to the 'degree of seal', or lack thereof, but it will start as soon as the CO2 being produced is less that the desire of air to get in. If you retro-fit a coil into your conical, it needs to be near the top of the liquid to prevent stratification, and you would still need to insulate the exterior, or place it in a insulated box (like a fridge!). If it isn't welded in to the lid, sanitizing or pressurizing will be trickier.

In your situation, the only practical app I see for the aq. chiller is to chill the tower of your kegerator, but even that can be done easier with a fan. Although using the aq. chiller will give you bragging rights, without negatively impacting your beer.

First off&#8212;Happy "Repeal Day"&#8212;the 21st Amendment was passed 78 years ago today!!!!

I think I am going to respectfully disagree... Based on my observations.

I tended to think the chest freezer was a better option (I have used lots of them for more than a decade), but after a couple days with this chiller--at least for keeping ales at 60-70F--this chiller is much better. And I think much more efficient. Maybe significantly so.

I was thinking about insulating both the fermenters, but I think it is not necessary for ales based on this batch's performance. The room temperature is about 70-75F and the thick stainless pot is enough insulation for me; the chiller has run less than three hours over the last 24 hours to keep an active ferment at 62F. That ain't much (especially compared to the amount a freezer's compressor runs with a 12 gallon batch).

Both the fermenters (brew kettle and the conical) have thermowells so the temperature is of the fermenting beer (the conical just isn't fermenting anything right now&#8212;but will be&#61514.

I also have two freezers rigged up with thermostats and (have and do) use them a lot--so I am not blowing smoke out my butt when I compare the chiller's performance to a chest freezer's...

I don't know the math or the "physics" behind it--I am just a stupid attorney--but I'll tell you chest freezers run constantly (when lagering and near constantly for ales) whenever they are full of fermenting beer (20-30 gallons) AND the temperature controller is set to read actual fermenting beer temperature via a thermowell. My best guess to the reason is--because cold air doesn't efficiently transfer through the fermenter material (steel, glass, plastic--I have used them all). In contrast, the chiller with cold water bath and direct contact with the fermenting beer&#8212;uses the insulating properties of the fermenter material help keep the cold in&#8212;rather than fight those insulating properties by trying to get the cold in.

AND, if 1/10 hp chiller compressor is much smaller (and I assume uses less electricity than a freezer compressor)--than all the better. Like I said, for 12 gallons of actively fermenting wit beer--the compressor on the chiller has run less than three hours per day (so far). A wit beer is about as vigorous a fermenter as I have brewed&#8212;so probably pretty representative.

Even if you add the couple hours it took to drop the bath water down to 45-50F at the start--that isn't all that much. And that's without insulating the fermenter (which I am thinking is not necessary for an ale anyway--the temperature difference between the room and the ferment just isn't enough to justify it).

I will brew a lager next weekend and see if insulating the fermenter for lagers is worth the added hassle. It very well might be. I hope not. My gut says the stainless steel is probably good enough insulation. Probably depends if I am fermenting at 45F or 55F. The latter less likely and the former more likely needing insulation.

Again--I might be wrong--because I have not measure electrical use for either a freezer or this chiller--ever-->

But judging by the amount the compressors run (chiller vs. freezer)--the chiller runs WAY less. Again, probably because it is directly cooling the beer via the stainless coils inside the fermenter.

For example, the fermenter is set at 62F. When the temperature rises to 63F, the pump from the cold water bath (50F) kicks on. It takes about 3 or 4 minutes and 12 gallons of beer is back to 62F. That is WAY quicker than a chest freezer is capable of.

The bath water warms up about a degree as well, so the chiller kicks on when the bath water is 2F above the set point (52F). It takes a while to hit 52F since the bath water is heavily insulated in the cooler. Like I said, the chiller only has run a three hours a day (so far). The beer also stays at 62F for a while&#8212;a couple hours anyway (I haven't timed it). And that's without any insulation.

The extra couple of dollars I spend by not insulating the fermenter are meaningless to me. My goal is not to be the most efficient--but I won't complain if the chiller is v.s a fridge or freezer. My goal is to use the stuff I have on hand&#8212;AND most importantly to make brewing convenient.

On that later factor--convenience--I will tell you that not cramming a large fermenter in a fridge or freezer and then working in that tight space--is AWESOME. Insulating would take away from that awesome/easiness factor&#8212;so I would rather not if I don't have to.

Putting the fermenter out in the open--on a table--makes SO much easier to fill! I can use a bucket and easily to do so just by dumping it in. No need to pump from kettle to fermenter.

As for the loose lid on the kettle for fermenting... IME there is absolutely no need for a tight fitting seal on a primary fermenter. I don't even think there is much of a need to tightly seal a secondary fermenter--unless you are opening and closing it&#8212;or doing something that pushes the CO2 out of the fermenter's head space.

I use corny kegs for secondary fermenters and just unscrew the relief valve--leaving the beer open to the air. No problems whatsoever for over a decade. So long as there is at least a tiny degree of fermentation going on there is no need to seal tightly. If you are correct and CO2 leaves the head space--it isn't enough to impact the beer. I am drinking some beers I brewed well over a year ago and were in cornies with no relief valve for at least a couple weeks after the primary fermentation transfer. My bet the beer in the kettle is more than fine for at least a week or so after primary fermentation ends (if I left it there).

The comment on cooling wort down after a boil, I think you are right, but I haven't and don't plan on trying to do that with the chiller.

I can get to 80F with an immersion chiller in the kettle. Even the piss warm Florida tap water allows me do that relatively easily. That said, the chiller did work great for dropping the wort down from 80F to 62F before pitching the yeast. Don't remember but it was a matter of minutes. Warmed up the bath a bit--but the chiller chilled it back down in a matter of minutes as well...

Anyway&#8212;for those thinking of immersion style chilling devise for fermentation&#8212;it works well. Probably could just add ice to cooler every day or so and pump in the immersed coil via a fish pump. Then no need for the compressor style chiller. That might be a good cheapy version of this.

DrewBrewTheGreat said:

I don't know the math or the "physics" behind it

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The physics don't fit with any of your assumptions, but it doesn't really matter as long as you are happy.

cwi said:

The physics don't fit with any of your assumptions, but it doesn't really matter as long as you are happy.

Click to expand...

One thing I learned in law school is that theory has a sneaky way of not working out in reality.... I think you are making the "assumptions" based on calculations from god knows where.... Or even if sound calculations--they are sound only in the textbook--away from other mitigating factors.

Seems you admit the internal chilling is more efficient--you just seem to think the fermenter needs to be insulated.

I think you are vastly overstating the need for the fermenter to be insulated (especially from room temperature air that is only a few degrees warmer).

In contrast "my assumptions" are actual observations. I observe a chest freezer full of actively fermenting beer makes a freezer compressor run-->a lot. My observations on chest freezers are based on dozens, if not hundreds, of batches in chest freezers.

In contrast, I observe this chiller running MUCH LESS.

Without the use of my handy, dandy, calculator-watch, and a physics textbook--that means to me that less electricity is being used.

That said--if you show me where I can find a used fridge that can fit both fermenters for "$50 on Craigslist" that works--I'll buy it. The wife would have gone for that...

Edit: Realized I am arguing about maximum a couple dollars:
Chiller = 1270 BTUs/2.63 amps/115V (or about 300 watts/Watts = Amps x Volts) http://www.marineandreef.com/JBJ_Arctica_Chiller_Titanium_JBJ_Chiller_s/514.htm

Jacksonville electric rate: 6.34 cents per kilowatt hour http://www.jea.com/about/pub/downloads/ElecTariffLEGAL10-01-2011.pdf

Formula for Estimating Energy Consumption

(Wattage × Hours Used Per Day) ÷ 1000 = Daily Kilowatt-hour (kWh) consumption x number of days x electric rate = cost

(300 watts x say 12 hours per day (four times a much as I have observed the chiller run!) x 10 day (days of fermenting in primary) / 1000) x 6.34 (electric rate) = $2.28 total cost for running chiller for ten days of primary fermenting (assuming it runs 12 hours per day--which is multiple times more than it is!)

I think I can live without insulation...

P.S. I think it would be easy to use one of these stainless coils as immersion chiller for 5 gallon batch--then use the coil again to chill a primary fermentation in a bucket fermenter. Just hook the stainless coil up to fish pump in a small cooler of ice water. I bet you would just have to add ice every day and you could do lagers pretty easily. Slow the flow to control the temp or buy a cheapy ebay temp controller....

Maybe cwi could figure out the "physics" of that... but I just think it might work based on a hunch.

I have to backup Drew's claims. I use a substantially similar system. Although looks like I have a slightly larger chiller (and one that I custom built out of scrap parts)

Switching from air cooling to glycol cooling was more efficient, despite having my conical's hanging out in the air with no insulation. I've since finished the box they go in, such that it has a door that is insulated...but mostly because I needed to heat them, and to reduce the condensation that formed when crash cooling the beer...and it's in my garage which runs between 120F and 40F.

Heat transfer is a function of delta temperature, and if you your ambient temp isn't far off from the target temps, you won't have much trouble with heat loss. One of the functions of a cooler for fermenting wort is to remove the heat produced by the yeast during fermentation (an exothermic process)

I have a much larger system running at a microbrewery (8 110 gallon HDPE conicals) and at normal ale temps, the lack of insulation in the system is not an issue.

Nice doodle!

Shockerengr said:

I have to backup Drew's claims....[]an exothermic process[].

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An "exothermic" process... Someday, that word will make it into a legal brief. I don't know for what or why. But it just will. Perhaps just to make a judge or clerk look it up. That is just a cool word.

Question for Shockerengr:
With my "brew room" temperature typically ranging from 50F (nights and mornings) to 80F (couple hours in the afternoon) (wild swings in temperature from day to night in Jacksonville during the winter)-->How low of a temperature do you think I can lager at? Without the use of insulation on the conical? I am not opposed to insulating it--just seeing if I can get away with not insulating--like it seems I can for ales.

I guess my question stated another way is---at what temperature differential (between room and ferment) do you think requires insulation based on your experience?

kpr121 said:

Nice doodle!

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He prefers being referred to as "Project Manager" jk.

p.s. Best dogs ever... A (mellow) golden retriever that doesn't shed. And pretty smart too.

I have one too, hes about 18 months, and my parents have a 3 year old. I have to agree they are one of the best, kindest, most gentle breeds. My wife wouldn&#8217;t know what do without that expensive mutt.

On topic, I think this is an excellent idea, don&#8217;t let the naysayers tell you differently. Great use of things that you already have, and I would agree with you that you most likely have more precise temperature control of the actual wort. And it is a great conversation piece (that&#8217;s what I call all my brew gadgets)!

DrewBrewTheGreat said:

Question for Shockerengr:
With my "brew room" temperature typically ranging from 50F (nights and mornings) to 80F (couple hours in the afternoon) (wild swings in temperature from day to night in Jacksonville during the winter)-->How low of a temperature do you think I can lager at? Without the use of insulation on the conical? I am not opposed to insulating it--just seeing if I can get away with not insulating--like it seems I can for ales.

I guess my question stated another way is---at what temperature differential (between room and ferment) do you think requires insulation based on your experience?

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Ok, so there's a few issues that start to grow in importance as you go colder.

1st, as you get colder, the delta temp between the wort and the room increases, increase the heat loss to the room. also, once you drop below the dew point, condensation becomes a problem (as you saw on the lines) Condensation also causes causes a lot of energy transfer into the wort.

So, depending on humidity somewhere around to just below lager temps can get difficult and messy to deal with do to heat load and condensation. (and sometimes in the summer here, even ale temps)

The next issue, is as the temp of the wort drops, the delta temp between the wort and the glycol shrinks such that your ability to move heat from the wort into the glycol decreases.

So for my system here's what I've noticed:

1. I keep my glycol between 29 and 36 degrees F (compressor kicks on at 36, off at 29) and have about 12 gallons of glycol.

below about 45 degree wort temp, I find that the rate of temp drop gets very slow as my heat transfer is poor...probably only moving about 1000-1200 btu's an hour at that point. so without insulation and 32deg glycol water, I wasn't able to get much below 45.
With the microbrewery, I've seen similar results, in fact, for crash cooling, they only tend to go to 50 degrees and aren't currently lagering.

I did do a lager before I had the doors on, and the temp got up to 90. it held temps at 52, but I found it running a lot more often. Having it inside the insulated box helps.

DrewBrewTheGreat said:

One thing I learned in law school is that theory has a sneaky way of not working out in reality.... I think you are making the "assumptions" based on calculations from god knows where.... Or even if sound calculations--they are sound only in the textbook--away from other mitigating factors.

Seems you admit the internal chilling is more efficient--you just seem to think the fermenter needs to be insulated.

I think you are vastly overstating the need for the fermenter to be insulated (especially from room temperature air that is only a few degrees warmer).

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Law school is not the ideal place to learn about physics. Theories in physics are very rarely proven false or to 'not work in reality. Especially those founded since the last century, and especially based on observations made while chilling beer in a garage in Florida. Perhaps in law school, or later, you studied the latest trial of "intelligent design" vs. evolution. Scientific theory is pretty well defined in it, as well as what laymen consider theory.

The biggest difference, though, is that I am basing my hypothesis on 'laws' of thermodynamics which even exceed the test for 'scientific theory'. The first law is a good read if you are interested.

I did not explicitly state that none of the suggestions were merely for the sake of saving a few bucks of elec. The were for system performance (better beer), regardless of energy cost. Most just happen to go hand in hand with energy savings because of those pesky thermo laws. Ease of use, on the other hand, is matter of personal choice, which I referred to in my post. That can involve trade-offs, but it doesn't change what the optimal choice is regardless of personal preference.

Here is the executive summary, talking points, bullets, or whatever the superficial treatment term of choice is:
Conservation of energy
Temperature Stratification
Heat transfer rate vs. efficiency
capacity vs. efficiency vs. reserve power

I can lay out all of the factors at play, but it would an even drier read than this already is. Some basics are: (some assume ambient temps are warmer than ferm temp)

The aq chiller can have a higher COP (chill/power) at normal temps because the temp of the evaporator is higher.

The aq chiller can be more energy efficient if its motor, etc. is smaller than a freezer's and closer the steady state chilling needs of the vessel. This is a negative if reserve power is needed for ramping/crashing.

The 'coil in liquid' can have a higher transfer rate, but is no more efficient in terms of energy usage in and of itself. Where it can increase energy eff is that it can chill faster than a freezer can, so the freezer is running and losing more heat (cold) to ambient for a longer time while waiting for the much colder air to more slowly transfer enough heat (cold) into the fermenter.

A freezer is insulated to prevent loss of heat (cold) to ambient. Keeping your uninsulated fermenter in the open air, it is constantly losing heat (cold) to ambient at rate related to the temp diff, but always higher than the vessel in a freezer. Your assumption that the SS metal provides insulation is true, but if you apply your same insulation value to that as you do your SS metal coil, it wouldn't work very well. In reality, the metal shell provides virtually no insulation. The main insulation is the ambient air and boundary layer of air (and beer) close to the vessel wall. Even if your chiller can keep up with the rate of heat loss, there are downsides other than higher energy usage.

One downside to not insulating, or not using a freezer, is radial temperature stratification. That is a fancy way of saying that your beer will be different temps at the vessel wall, and near the coil. The diff depends on many things, but especially ambient temps. Coil and probe placement can mitigate this, but it is not a simple issue especially if ambient temps vary. The fact that your fermenter doesn't sweat may be a sign of this, especially if the dewpoint has been lower than ferm temp lately. Trying to do a lager, or crash cool, doesn't improve the stratification or heat (cold) loss situation, and also reduces your crash rate.

Having said all that, the differences are not that great, except for the temp statification, lagering, and crashing in open air scenarios. If a chest freezer can't keep up with a 30gal ferm, a much smaller, or even similar sized, aq chiller won't be able to either, especially if the 30 gal under aq chilling is uninsulated in the open air. In practice, a freezer using air to transfer heat into a glass or plastic carboy, or metal conical, has no problems keeping up with a ferm even if it is chock full.

Typical "on times" are < 10 min/hour. A crapload of active ale will obviously have higher on times, but a lager should be little different than keeping food at temp. Considering that a chest freezer has no issue keeping food at ~0F in a hot garage with ease, the fact that your lager experience required it running 24/7 does not match up with normal operation.

One thing for you to look into is Anti-Short cycle Delay (ASD). Most Ranco's don't have it; you want this. There are other measures to help prevent short cycling. You can kill your compressor in short order without it. In general, it only comes into play for exceptional circumstances.

Shockerengr,

Thanks for the helpful information. I like your setup a lot and the ingenuity required in creating it. I also like the cabinet idea--very open and easy work around.

That will be an option to consider for lagering I think.

With the brew room in our house as well as our dog (I mean Project Manager) while the wife and I are gone during the day--our a/c is always on and set. The hairy critter doesn't like heat and even with the a/c set at 78F in hot summer--he still finds cool tiles in the bathroom. So that is about the hottest temperature I have to combat. Not quite like the heat you are occasionally dealing with in your garage.

However, I like lagers... So it seems based on your experiences--either a cabinet or some type of insulation for lagering is in order.

I originally set the chiller, for this ale, at 40F, then 45F, now 50F. The chiller didn't have problem with any of those temperatures. If I set the 10-15 gallons of bath water at 35F or 40F do you think that chiller can lager at 50F? (you seem have a handle on the numbers--removal of btu's, etc,--better than I)

Also, I am not running glycol, just r/o water with a light touch of iodine based sanitizer to help keep out any funk.

Is there any reason glycol is necessary? Just for below freezing temps? Have you ever run the system warmer than 29F?

How does one figure out the ideal temperature of the bath water? Ideal being perhaps with goal of (1) keeping the ferment at the temperature you want AND (2) minimizing the chiller's run time.

Anyone:

I found a link to this type of insulation on a search on this forum a while back...

http://www.mcmaster.com/#9349k3/=f8yyvo

Not even sure where I found it in the forum--just bookmarked the link b/c it looked perhaps useful for something, someday...

Anyone use the stuff. Any thoughts on it working to make removable insulation for the conical? It's a little pricy. Any alternatives? Project Manager's (dog) blanket? hehe...

Shockerengr said:

Heat transfer is a function of delta temperature, and if you your ambient temp isn't far off from the target temps, you won't have much trouble with heat loss.

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Using that logic, a chest freezer also won't lose that much heat to ambient either. If so, how can the aq chiller be that much more efficient than a freezer? In reality the chest freezer, and especially an uninsulated fermenter, loses a significant of it overall heat to ambient.

Aq chillers, or even a homebrewed submerged glycol chillers, benefit from higher evaporator temps, but it isn't that great of an advantage. Certainly not enough to offset a fermenter inside an insulated space (freezer) vs. an uninsulated fermenter in open air within normal, and especially extreme, ambient ranges.

Shockerengr said:

One of the functions of a cooler for fermenting wort is to remove the heat produced by the yeast during fermentation (an exothermic process)

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The heat produced during ferm isn't very large. Most observations have it requiring around a 10F ambient differential with ~10% duty cycle to maintain a fermenter at typical ale temps in a freezer. I would have to run some numbers, or just look up the known rates, to figure what power and total energy is being generated during ferm.

Shockerengr said:

I have a much larger system running at a microbrewery (8 110 gallon HDPE conicals) and at normal ale temps, the lack of insulation in the system is not an issue.

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How is your stratification these days?

What happened between the previous post and this one?

Shockerengr said:

Heat transfer is a function of delta temperature, and if you your ambient temp isn't far off from the target temps, you won't have much trouble with heat loss.

I have a much larger system running at a microbrewery (8 110 gallon HDPE conicals) and at normal ale temps, the lack of insulation in the system is not an issue.

Click to expand...

Shockerengr said:

Condensation also causes causes a lot of energy transfer into the wort.

So, depending on humidity somewhere around to just below lager temps can get difficult and messy to deal with do to heat load and condensation. (and sometimes in the summer here, even ale temps)

The next issue, is as the temp of the wort drops, the delta temp between the wort and the glycol shrinks such that your ability to move heat from the wort into the glycol decreases.

below about 45 degree wort temp, I find that the rate of temp drop gets very slow as my heat transfer is poor...probably only moving about 1000-1200 btu's an hour at that point. so without insulation and 32deg glycol water, I wasn't able to get much below 45.
With the microbrewery, I've seen similar results, in fact, for crash cooling, they only tend to go to 50 degrees and aren't currently lagering.

I did do a lager before I had the doors on, and the temp got up to 90. it held temps at 52, but I found it running a lot more often. Having it inside the insulated box helps.

Click to expand...

cwi,

God love you--you are numbers cruncher--and you (and people like you) make the world work... Exponentially more than any attorney. I have respect for that.

However, I am just telling what I observe. None of my chest freezers like 20-30 gallons of actively fermenting ale or lager. If you are asking me to believe you over my own eyes--than I am sorry--we disagree.

The chest freezer (that I can easily get to the back of and read the tag) by the way is only rated at 1.6 amps. So that may play into calculations.

It's a typical chest freezer and I doubt other chest freezers are much different. It holds four corny kegs plus a bit more. Fill it with fermenting beer and it will hold temps (read via thermowell) fine; however, the compressor runs way more than this chiller (1/10 hp).

As i said before, a larger chest freezer had 30-35 gallons of lager (pilsner) and it did not stop running for almost two weeks.

That is not even debatable, it is just an observation....

EDIT:

"How is your stratification these days?"

That isn't really an issue with fermenting beer... Especially in a conical. The fermentation mixes the wort all around. Ever look at a carboy fermenting? The conical's shape accentuates this mixing.

Even in my flat bottomed kettle-- i started with the coils at the top (cold drops)--and then once fermentation begin--I just dropped the coils on to the bottom of the (flat bottomed) fermenter.... I have taken several temperature readings with a long probe thermometer. There is not any stratification during the fermentation.

That was a concern (in theory). It turned out--in practice--not to be a reality--because of other mitigating factors (e.g. the fermention mixes the beer).

"The heat produced during ferm isn't very large."

That statement I suspect is completely wrong. Again relying purely on experience. 5 gallon batches raise temp a couple degrees above ambient. My conical full (10-11 gallons) raise temperature 5-8 degrees above ambient at peak fermentation. I imagine batches larger--and any commercial brewer can probably attest to this-- would raise fermenting temperatures significantly above ambient if not controlled (via jackets or immersion devices).

Your assumption that the SS metal provides insulation is true, but if you apply your same insulation value to that as you do your SS metal coil, it wouldn't work very well.

The difference is that chest freezers have to penetrate the stainless insulation (of fermenter wall) via cold air.... That transfer is relatively inefficient. In contrast, the coil submerged in the fermenter is transferring cold through the stainless steel via direct contact with a liquid.

No number crunching required: Stick your hand in the freezer and then stick your hand in a bucket of ice water---then tell me which makes your hand colder more quickly!

cwi said:

Using that logic, a chest freezer also won't lose that much heat to ambient either. If so, how can the aq chiller be that much more efficient than a freezer? In reality the chest freezer, and especially an uninsulated fermenter, loses a significant of it overall heat to ambient.

Click to expand...

Two reasons, surface area, and delta T.

The surface area of the fermenter is significantly less than that of the of the fridge/freezer to outside world. Less surface area offsets some of the benefits of the insulation in the freezer...which often isn't much (R3-R7)

Second, is Delta T.
I prefer to control my temps based on the temp of the wort, not the surrounding air, because wort temp is really what I care about. Because air is a poor conductor of heat, and because water/wort has a very high thermal mass, the air temp in the fridge/freezer ends up dropping fairly low to get decent heat transfer out of the fermenter.

If you only control air temp, that's less of an issue, but it's not something I'm interested in doing.

cwi said:

Aq chillers, or even a homebrewed submerged glycol chillers, benefit from higher evaporator temps, but it isn't that great of an advantage. Certainly not enough to offset a fermenter inside an insulated space (freezer) vs. an uninsulated fermenter in open air within normal, and especially extreme, ambient ranges.

Click to expand...

I don't believe this is a factor at all, my evaporator temps are somewhere around 15 degrees in the glycol bath. In a freezer/fridge, they'll be anywhere from -10 to 45 depending on how long the cycle times are.

cwi said:

The heat produced during ferm isn't very large. Most observations have it requiring around a 10F ambient differential with ~10% duty cycle to maintain a fermenter at typical ale temps in a freezer. I would have to run some numbers, or just look up the known rates, to figure what power and total energy is being generated during ferm.

Click to expand...

For the 85 gallon batches at the microbrewery I sized the system around a peak fermentation output of 1000 btu/hr. That would be a vigorous fermenation that would substantially complete in 24-48 hrs. a more typical case will be around a half to a third of that. As for your duty cycle assuming that your freezer is capable of 1000 BTU/hr (not sure what how big a chest freezer you have, but that would be ballpark) a 10% duty cycle would be consistent with about half that energy coming from ferementation.

cwi said:

How is your stratification these days?

Click to expand...

It's not as much of an issue as is being made out. During active ferementation it's a non-issue because the turbulence caused by the co2 outgassing is more than enough to mix. The rest of the time it's easily solved by having the coils at the top of the chamber. Convective currents are enough to stir the mix.

If you have a layer above the top of the coils you can have an issue, esp the more rapid the chill down.


There are a lot of benefits I find from using the glycol system over the fridge:
*It's much more compact
*It has a much higher performance for what I need because of the large resevoir of cold glycol
*I get VERY precise temp control - as little as .1F without ever having to worry about short cycling a compressor.
*30 minutes to go from 80 to 60 with 10 gallons is quite handy for my uses.

DrewBrewTheGreat said:

However, I am just telling what I observe. None of my chest freezers like 20-30 gallons of actively fermenting ale or lager. If you are asking me to believe you over my own eyes--than I am sorry--we disagree.

The chest freezer (that I can easily get to the back of and read the tag) by the way is only rated at 1.6 amps. So that may play into calculations.

It's a typical chest freezer and I doubt other chest freezers are much different.

Click to expand...

This would be consistent with my calculations. You're probably putting out 200-500 BTU/hr from the ferementation in a chest freezer probably rated around 700 BTU/hr

DrewBrewTheGreat said:

I originally set the chiller, for this ale, at 40F, then 45F, now 50F. The chiller didn't have problem with any of those temperatures. If I set the 10-15 gallons of bath water at 35F or 40F do you think that chiller can lager at 50F?

Click to expand...

If the btu/hr capacity of the chiller is enough to keep up with ferm heat and heat loss, there is no reason for the bath. You can just hook the chiller straight up to the coil in the fermenter. The bath serves as a battery, which can provide surge capacity to deal with 'spikey' heat events, if they are an issue. It can also smooth out short cycling issues, if those are an issue sans bath.

DrewBrewTheGreat said:

How does one figure out the ideal temperature of the bath water? Ideal being perhaps with goal of (1) keeping the ferment at the temperature you want AND (2) minimizing the chiller's run time.

Click to expand...

Why do want to complicate things by trying to save a few bucks by minimizing the chiller run time? Just being a smart ass.

The chiller will have to run more the colder you keep the bath temp below the min temp necessary to maintain ferm temps. The extra run time covers the heat loss of the bath, among other things. To protect your chiller, what you really want to do is reduce the number of cycling events. This will mean setting the bath colder than necessary with a very wide temp diff. There is some overall wear and tear balancing between cycling less due to a wide diff, and total running time being longer due to the colder bath temp. In general, reducing cycling is of greater benefit. See earlier comment about getting rid of the bath altogether. You would need to see what kind of cycling this causes.

How about putting the lid on the cooler you use as a bath to help things out?

cwi said:

What happened between the previous post and this one?

Click to expand...

My garage hits 120 degrees? The brewery only about 85?

And for your answer, insulating doesn't help me hit more than a degree or two cooler on chill down....

To be honest...the biggest reason I put the doors on this fall was to control condensation when lagering, followed by using a heat lamp to heat the air to a minimum temp.

DrewBrewTheGreat said:

Shockerengr,

I originally set the chiller, for this ale, at 40F, then 45F, now 50F. The chiller didn't have problem with any of those temperatures. If I set the 10-15 gallons of bath water at 35F or 40F do you think that chiller can lager at 50F? (you seem have a handle on the numbers--removal of btu's, etc,--better than I)

Also, I am not running glycol, just r/o water with a light touch of iodine based sanitizer to help keep out any funk.

Is there any reason glycol is necessary? Just for below freezing temps? Have you ever run the system warmer than 29F?

How does one figure out the ideal temperature of the bath water? Ideal being perhaps with goal of (1) keeping the ferment at the temperature you want AND (2) minimizing the chiller's run time.

Click to expand...

Glycol was necessary because the evaporator temps run about 15 degrees below the the glycol temp, so starting around 40, ice becomes an issue.

I have mine set to 29 because any colder and I'd start having to worry about ice buildup outside of the glycol, and it allows me to run a really wide set point for the chiller. The higher delta T also helps to keep the pump run times down. For ales, I'd could go up to 45 or 50, depending on the ale temp.

At the brewery, I also run 29 degrees for similar reasons, although in operation, the temp will rise higher if a lot of fermenters are demanding chilling at once.

DrewBrewTheGreat said:

cwi,

God love you--you are numbers cruncher--and you (and people like you) make the world work... Exponentially more than any attorney. I have respect for that.

Click to expand...

Yet we constantly have tell guys that the perpetual motion machine the attorney tells them is a shoe in for a patent just as soon as he gets his retainer, is just not physically possible.

DrewBrewTheGreat said:

However, I am just telling what I observe. None of my chest freezers like 20-30 gallons of actively fermenting ale or lager. If you are asking me to believe you over my own eyes--than I am sorry--we disagree.

Click to expand...

Is it plugged in? (tech support joke)

I am telling you that if your chest freezer can't handle whatever size batch of of lager that can fit into it, which is an extremely low power ferm, it also wouldn't be able to keep food at ~0F. That means something isn't right with the chest freezer. Also, small muffin fans help with the heat transfer issues in chest freezers. Fridges already have them, but can still benefit.

DrewBrewTheGreat said:

The chest freezer (that I can easily get to the back of and read the tag) by the way is only rated at 1.6 amps. So that may play into calculations.

That sounds a bit small, but probably in the normal range. Larger ones will have larger compressors. They can remove about double the power/energy input.

It's a typical chest freezer and I doubt other chest freezers are much different. It holds four corny kegs plus a bit more. Fill it with fermenting beer and it will hold temps (read via thermowell) fine; however, the compressor runs way more than this chiller (1/10 hp).

1/10 hp = ~100W
Try with similar amounts of fermenting beer.

DrewBrewTheGreat said:

"How is your stratification these days?"

Click to expand...

That isn't really an issue with fermenting beer... Especially in a conical. The fermentation mixes the wort all around. Ever look at a carboy fermenting? The conical's shape accentuates this mixing.

Click to expand...

It is only that active for what, 3-4 days. Try a search for 'conical stratification".

DrewBrewTheGreat said:

Even in my flat bottomed kettle-- i started with the coils at the top (cold drops)--and then once fermentation begin--I just dropped the coils on to the bottom of the (flat bottomed) fermenter....

Click to expand...

If the coils cover the volume sufficiently, or are in the correct position, it can mitigate stratification.

DrewBrewTheGreat said:

That was a concern (in theory). It turned out--in practice--not to be a reality--because of other mitigating factors (e.g. the fermention mixes the beer).

Click to expand...

You have modified the premise of the theory. You are now using "special fermentation stratification" theory instead of "general fermentation stratification" theory. The only sin bigger in the nerd world is "Applying a Star Trek solution to a Babylon 5 problem".

Why do want to complicate things by trying to save a few bucks by minimizing the chiller run time? Just being a smart ass.

Not trying save electrical costs--trying to make sure the chiller lasts. Again, its only running about 3 hours a day (so far). Maybe a bit more today as fermentation ramped up, but I don't think so.

And it is not cycling often. My bet is it is designed to handle frequent cycling anyway--it's an aquarium chiller... from my experience with reef fish tanks and hot metal halides hanging above them (to grow coral) that's what these chillers do--cycle frequently! To maintain a precise temperature (a sudden drop of even just 2-3 degrees can bleach or kill stony coral).

there is no reason for the bath

1. How would I control two different fermenters independently.
2. The chiller came from a fish tank.... My beer is not going through it...

"put a lid on the bath"

There is a lid on the cold water bath--just not the white one. Black foam = hard to see in picture.

1/10 hp = ~100W
Try with similar amounts of fermenting beer.

The chiller runs at 2.6 amps and is 115 volt... I think your calculation is off.

http://www.marineandreef.com/JBJ_Arctica_Chiller_Titanium_JBJ_Chiller_s/514.htm

This weekend there will be 22 gallons going... Again--the chiller isn't struggling with 12 gallons. It's barely running. Maybe 4 hours a day and that being generous. That 80 cents per 10 days in Jacksonville.

If the chiller jumps to running 12 hours a day (3X more) that will be $2.28 per 10 days in Jacksonville.

I know were are in a depression and all--but I think I handle those costs.

In contrast, once again, nothing is wrong with chest freezers. However, if they have 20-30 gallons of fermenting beer--they run near or totally constantly. They do a good job and maintain the temperature I want; however, you have failed to convince me (or likely anyone) that the chest freezer is more efficient to use for that volume of beer.

That said, the my secondary fermentation will be in chest freezers. It has nothing do with efficiency. My secondaries/serving vessels are corny kegs and I can fit butt load of them in the chest freezers. The chest freezers do not run all the time to maintain non-fermenting beer at any temperature. Chest freezers, IMO, for that purpose, are ideal.

Chest freezers also work well for primary fermenting--the compressor just runs more than this chiller set up and the temperature control does not respond as quickly.

DrewBrewTheGreat said:

"The heat produced during ferm isn't very large."

That statement I suspect is completely wrong. Again relying purely on experience. 5 gallon batches raise temp a couple degrees above ambient. My conical full (10-11 gallons) raise temperature 5-8 degrees above ambient at peak fermentation. I imagine batches larger--and any commercial brewer can probably attest to this-- would raise fermenting temperatures significantly above ambient if not controlled (via jackets or immersion devices).

Click to expand...

I said it requires about a 10F ambient differential.
By not very large, I mainly meant in relation to the chiller capacity. Even a 10 gal batch doesn't produce that much power during ferm. What do you consider large? It is obviously much less than the capacity of my freezer that runs <10% duty cycle even at >80F ambient. So I guess around 1W/gallon, or less depending on the ferm temp. Definitely within an order of magnitude of that.

DrewBrewTheGreat said:

Your assumption that the SS metal provides insulation is true, but if you apply your same insulation value to that as you do your SS metal coil, it wouldn't work very well.

The difference is that chest freezers have to penetrate the stainless insulation (of fermenter wall) via cold air.... That transfer is relatively inefficient. In contrast, the coil submerged in the fermenter is transferring cold through the stainless steel via direct contact with a liquid.

No number crunching required: Stick your hand in the freezer and then stick your hand in a bucket of ice water---then tell me which makes your hand colder more quickly!

Click to expand...

I don't think you are getting it. You said the stainless provided insulation. I believe I was very clear in my explanation of air/beer boundary layers, transfer rates of air vs. water, etc. As long as the freezer can transfer, via air, enough heat to the fermenter in a sufficient amount of time to maintain temps, it doesn't matter that the transfer rate is lower than liquid-metal-liquid transfer rates, it is sufficient for the task at hand.

As long as the freezer can transfer, via air, enough heat to the fermenter in a sufficient amount of time to maintain temps, it doesn't matter that the transfer rate is lower than liquid-metal-liquid transfer rates, it is sufficient for the task at hand.

I never question sufficiency--when I say the freezer struggles with large batches--I mean the compressor runs--near constantly or constantly. The chest freezer does a great job (maintains the temp); however, it just wears itself out all day long doing it--> when fermentation is active.

The chiller again, in contrast, runs briefly and then shuts off. The pump in the bath water kicks on every couple hours to drop the fermenter temperature down.

The chiller does the same job as the chest freezer--maintains the temperature of the ferment--> it just does so without the compressor needing run all the time.

That is my point... It is an observation. Not debatable.

Here, let me talk cave man:

Freezer = compressor run a lot during active ferment and large batch

Chiller = compressor run WAY LESS during active ferment

Both = maintain temperature

Both = work

Benefit of chiller = more quickly adjusts temperature and compressor runs less when controlling temperature of dedicated fermenters (even without insulation at ale temperatures).

Benefit of Freezer = more capacity for lots of kegs and more versatile.

Downside of Chiller = may need to insulate the fermenter for lagers or compressor will run more often.

Shockerengr said:

Two reasons, surface area, and delta T.

The surface area of the fermenter is significantly less than that of the of the fridge/freezer to outside world. Less surface area offsets some of the benefits of the insulation in the freezer...which often isn't much (R3-R7)

Click to expand...

This doesn't match up with you having to place your conical in a cabinet, while I can ferment and cold crash in less than 12 hours in fridge in a 100F garage. Stainless steel R value is ~0. Chest freezers are ~R15. Also, if you use an appropriate size of chamber for the vessel, the difference in surface area won't overcome the uninsulated open air fermenter in the same ambient.

Shockerengr said:

Second, is Delta T.
I prefer to control my temps based on the temp of the wort, not the surrounding air, because wort temp is really what I care about. Because air is a poor conductor of heat, and because water/wort has a very high thermal mass, the air temp in the fridge/freezer ends up dropping fairly low to get decent heat transfer out of the fermenter.

If you only control air temp, that's less of an issue, but it's not something I'm interested in doing.

Click to expand...

Controlling to wort temps is why I bought a controller, controlling the air means I have to be the second controller. Me no likey.

Why does it matter if the air drops to low temps in the chamber? Are you adding in constraints like the chamber also has to keep any bottles in the chamber at a specific temp range as well? In reality, the ambient doesn't go much below 20F lower than ferm temp during the active phase, and only ~10F max on average. Fans, thermal mass, and probe response tricks can reduce those if they matter to you.

Shockerengr said:

Aq chillers, or even a homebrewed submerged glycol chillers, benefit from higher evaporator temps, but it isn't that great of an advantage. Certainly not enough to offset a fermenter inside an insulated space (freezer) vs. an uninsulated fermenter in open air within normal, and especially extreme, ambient ranges.
I don't believe this is a factor at all, my evaporator temps are somewhere around 15 degrees in the glycol bath. In a freezer/fridge, they'll be anywhere from -10 to 45 depending on how long the cycle times are.

Click to expand...

You keep your glycol bath close to freezing though, right? If the bath was kept closer to the needed offset, the evap temps during "on times" could be significantly different. Even at the ranges you quoted, it could be enough to double the COP, but it has been a while since I looked at COP charts. I do remember that for one DC compressor setup, evap temps going from ~0F to 30F raised the COP from ~1 to 4. Evaporator temp control is coming in the next green fridges.

Shockerengr said:

For the 85 gallon batches at the microbrewery I sized the system around a peak fermentation output of 1000 btu/hr. That would be a vigorous fermenation that would substantially complete in 24-48 hrs. a more typical case will be around a half to a third of that. As for your duty cycle assuming that your freezer is capable of 1000 BTU/hr (not sure what how big a chest freezer you have, but that would be ballpark) a 10% duty cycle would be consistent with about half that energy coming from ferementation.

Click to expand...

A large percentage of low duty cycles like that are startup costs, but about 50% loss to ambient is definitely possible in the summer. I never really cared as long as it kept up with ferm, which it had no problem doing at 10%. Do you have an explanation why the OP couldn't get 30 gallons of low power lager to maintain temps in a freezer? Maybe he put it in hot? It still should have been able to start freezing it in 2-3 days max.

Shockerengr said:

It's not as much of an issue as is being made out. During active ferementation it's a non-issue because the turbulence caused by the co2 outgassing is more than enough to mix. The rest of the time it's easily solved by having the coils at the top of the chamber. Convective currents are enough to stir the mix.

If you have a layer above the top of the coils you can have an issue, esp the more rapid the chill down.

Click to expand...

I forget the specifics, but after the highly active phase radial and vertical strat is a confirmed issue for jacketed conicals. With a non-jacketed, non-insulated conical, I can't imagine it gets better. With a large single wall internally chilled conical, radial strat, or a least a boundary layer at the vessel wall is highly likely, maybe even during active ferm depending on ambient. There is a lot of literature on strat issues, and how to mitigate it. You can choose to dismiss it if you like.

For homebrewers that primary for extended time periods, leaving a centrally chilled conical in an 10-20F ambient diff will certainly cause temp strat.

Shockerengr said:

*I get VERY precise temp control - as little as .1F without ever having to worry about short cycling a compressor.

Click to expand...

It is possible to get much more precise control with glycol, but if the ambient diff is large, it would be difficult realize it without insulation. That is why insulating the fermenter, or putting it in a fridge with ambient set to ferm temp, makes so much sense. Whether .1F is necessary, is another issue, but is good for bragging rights. No complaints from me if I could get it. I have dreamed up submerged kegs/fermenters as a poor mans jacket for multiple temps in one keezer/chamber. There are easier ways to do the same thing, but the liquid cooling has more sex appeal.

I didn't say there weren't benefits to glycol, and especially with a more substantial chiller like a fridge or A/C unit as the source, there are some cool things one can do. My suggestion was that to do any lagering (which the OP mentioned), or crashing, the conical will need to be insulated. At that point, it seemed like a free/cheap fridge would be easier/cheaper to deal with than finding/fitting/cleaning insulation for the conical. It may still be, even if just to get the ambient down, and still chill with the coil.

Shockerengr said:

This would be consistent with my calculations. You're probably putting out 200-500 BTU/hr from the ferementation in a chest freezer probably rated around 700 BTU/hr

Click to expand...

I don't doubt the aq chillers have an energy efficiency advantage over a freezer, and for sure an immersed coil has a transfer rate advantage of air. The question is what the multipliers are between them an chest freezers.

The OP's aq chiller is 1 amp max if the 1/10 hp rating is the compressor. A typical freezer is rated at ~5amps, but usually has a 2-3amp run current. Out of the gate the chiller would need a 3:1 multiplier given similar compressor designs.

I have ferm'd 12+ gallons in a 1/2 bbl in a 5amp rated fridge in a 100F garage. It had no issues during the peak ferm, and was never over temp with frequent checks. No logging or anything, but it had no problems. I think this is a common experience. I am sure others have done even larger batches, and have logging for on times, etc.

If the OP is having issues, especially ferming lagers which is basically just turning a chest into a kegerator as low power as lager ferments are, something is up. Keezers have no prob maintaining ~35F even with bare collars. Guys with logging report 10-20% duty cycles.

cwi,

I think you numbers are just screwy...

Chiller: 2.63 amp and 1270 btu's



JBJ 1/10HP Arctica Aquarium Chiller

Freezer: 1.6 amps (blame the tree huggers and their "green energy stars")


It certainly does not run 10-20% of the time FULL of active ferment! More like 70%+ during active ferment... I have never timed it, but the compressor is rarely off. Temperature of ferment is reached but is running near constantly.

cwi said:

This doesn't match up with you having to place your conical in a cabinet, while I can ferment and cold crash in less than 12 hours in fridge in a 100F garage. Stainless steel R value is ~0. Chest freezers are ~R15. Also, if you use an appropriate size of chamber for the vessel, the difference in surface area won't overcome the uninsulated open air fermenter in the same ambient.


Controlling to wort temps is why I bought a controller, controlling the air means I have to be the second controller. Me no likey.

Why does it matter if the air drops to low temps in the chamber? Are you adding in constraints like the chamber also has to keep any bottles in the chamber at a specific temp range as well? In reality, the ambient doesn't go much below 20F lower than ferm temp during the active phase, and only ~10F max on average. Fans, thermal mass, and probe response tricks can reduce those if they matter to you.

Click to expand...

The answer is it doesn't, You had asked for reasons why insulation is less of an issue in this case and I gave them.

cwi said:

You keep your glycol bath close to freezing though, right? If the bath was kept closer to the needed offset, the evap temps during "on times" could be significantly different. Even at the ranges you quoted, it could be enough to double the COP, but it has been a while since I looked at COP charts. I do remember that for one DC compressor setup, evap temps going from ~0F to 30F raised the COP from ~1 to 4. Evaporator temp control is coming in the next green fridges.

Click to expand...

Probably, or I can leave the controller at the low temp, not worry about stuff growing as fast, and let it run. I insulated the glycol tank with 3" of foam to compensate for the lower temps I run at...which is better insulation than the rest of the freezer's I have.

cwi said:

A large percentage of low duty cycles like that are startup costs, but about 50% loss to ambient is definitely possible in the summer. I never really cared as long as it kept up with ferm, which it had no problem doing at 10%. Do you have an explanation why the OP couldn't get 30 gallons of low power lager to maintain temps in a freezer? Maybe he put it in hot? It still should have been able to start freezing it in 2-3 days max.

Click to expand...

I think you're overestimating the heat transfer capacity of his keezer...not all are the same, and the newer units with better insulation have gotten smaller compressors. given the 1.6 amps, it's not going to be move more than about 500-700 btu/hr

cwi said:

I forget the specifics, but after the highly active phase radial and vertical strat is a confirmed issue for jacketed conicals. With a non-jacketed, non-insulated conical, I can't imagine it gets better. With a large single wall internally chilled conical, radial strat, or a least a boundary layer at the vessel wall is highly likely, maybe even during active ferm depending on ambient. There is a lot of literature on strat issues, and how to mitigate it. You can choose to dismiss it if you like.

For homebrewers that primary for extended time periods, leaving a centrally chilled conical in an 10-20F ambient diff will certainly cause temp strat.

Click to expand...

I'm not saying it's never an issue. I have to make a mod to one of my conicals because of it (the chiller is 4-5" below the surface of 10 gals...which as I said does cause stratification)

But I do believe it's being made into a much bigger deal than it needs to be. It's easy to fix...put the chiller coil such that it's at the top/surface and convection takes over from there. I did several tests with chillers when I was first setting up these system to confirm that stratification wasn't going to be a problem, and have probably 100bbls of brewed beer to back up that theory.

cwi said:

It is possible to get much more precise control with glycol, but if the ambient diff is large, it would be difficult realize it without insulation. That is why insulating the fermenter, or putting it in a fridge with ambient set to ferm temp, makes so much sense. Whether .1F is necessary, is another issue, but is good for bragging rights. No complaints from me if I could get it. I have dreamed up submerged kegs/fermenters as a poor mans jacket for multiple temps in one keezer/chamber. There are easier ways to do the same thing, but the liquid cooling has more sex appeal.

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There's no disagreement there, other than what each of us considers a large diff. I can run my system around 40-50 degrees below ambient, down to a wort temp of about 40-45. I limited more by the temps of the glycol on how low I can go than I am by the ambient temps. But above about 10-20 degrees below ambient, I suggest some form of insulation to prevent condensation issues and reduce system run times.

If I had my system in my house like the OP, and was only doing ales, I would suggest forgoing insulation for a glycol system with an internal chiller. The savings in energy aren't great enough to offset the cost of insulation for a 10-15 degree temp delta. I insulated mine because I have much higher temp deltas to deal with, and will have up to a barrel of beer fermenting at a time...which puts enough heat out on it's own that I'll use around half of the systems capacity just to remove the heat of fermentation.

(and as a note, I only control to .5 deg as I don't think .1 is necessary either)

cwi said:

I didn't say there weren't benefits to glycol, and especially with a more substantial chiller like a fridge or A/C unit as the source, there are some cool things one can do. My suggestion was that to do any lagering (which the OP mentioned), or crashing, the conical will need to be insulated. At that point, it seemed like a free/cheap fridge would be easier/cheaper to deal with than finding/fitting/cleaning insulation for the conical. It may still be, even if just to get the ambient down, and still chill with the coil.

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I wouldn't worry about it just for crashing...the time frames are short enough to ignore the inefficiencies.

As to the free/fridge comment. I used to use a fridge, I built the glycol system. I am much happier with the new setup and I find it to be more efficient than my previous setup. The insulation in the old fridge was only about r3-r5 (and I stand by that being typical for older fridges), it had air leaks, would freeze up and generally be a poor performer compared to what I have now.

I should also note, that I gutted the fridge to get the cooling system for my glycol system, so I have a direct comparison in performance between the two. Glycol works better. It's not for everyone, but for anyone that's interested, and is willing to set one up, I think they will be very happy with the end product. They are just so much more capable than a standard fridge.

kpr121 said:

My wife wouldn’t know what do without that expensive mutt.

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Oh yes! I am in 110% agreement with that statement.

I was skeptical about spending money on a dog--let alone a mutt--but "Project Manager" has been worth every penny. Had a few different breeds growing up--> there is no comparison with this guy. Just an easy, enjoyable, experience, all the way around from day 1 (8 weeks old).

Must be great when all those pups get together!

DrewBrewTheGreat said:

cwi,

I think you numbers are just screwy...

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You mean these numbers:

DrewBrewTheGreat said:

1/10 hp aquarium chiller

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They are your numbers, so who is screwy? It was all I had to go on, so that is what I used.
1hp = 750W (no matter whether the horse is submerged in a conical, or not)

Did you go to a law school that taught using the 'modified' Socratic method- lesson number one, bury them in documents and mix in some red herrings for good measure.

I can't even imagine what lesson number two would be, maybe the "Chewbacca defense".
[ame=http://www.youtube.com/watch?v=l1QI4P0YqtM]South Park - The Chewbacca Defence - YouTube[/ame]

DrewBrewTheGreat said:

Chiller: 2.63 amp and 1270 btu's

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More than likely that is peak, and not run current, but who knows. Something isn't right if it is using 3A steady and only claiming 1/10hp. No matter, the (claimed) btu rating is what is important. With a fridge, one has to go off watts and a WAG for COP.

DrewBrewTheGreat said:

Freezer: 1.6 amps (blame the tree huggers and their "green energy stars")

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This is what I was referring to about something being atypical with your experience. If the plate rating is 1.6A, you have a wimpy freezer. My puny freezer has a 5A plate rating The compressor run power is much less, but probably more than 1.6A. My old bigger one, RIP, had a ~4 amp motor.


It really makes no difference. The issue I am trying to convey is that you can't get more power out than you put in, regardless. It doesn't matter how good it transfers heat, there is only some much heat it can move based on the energy input (X COP for Carnot cycle devices). Yes, the aquarium chiller has advantages that can make it remove more heat for a given energy input, so it can have a lower % on time than an equivalent freezer. My comments were more related to what the analysis looks like, and what effects are at play.

What % on time the aq chiller has will be related by some formula to what a freezer % on time will be. With some empirical data, it would be easy enough to come up with one. However, for the same amount of beer, if a freezer has a 90% on time, an aq chiller with 1/3 the energy input only having a 10% on time would require a COP 9 times the freezer. That can happen in theory, but not in reality. This is a case where I agree with you on theory and reality not agreeing.

My original suggestion is now even more pertinent since you now seem to think insulating would be a good idea. If you feel that dealing with directly insulating the fermenter or building your own chamber, is easier than putting it in a fridge, that is a personal preference. Something I already mentioned.

Shockerengr said:

I think you're overestimating the heat transfer capacity of his keezer...not all are the same, and the newer units with better insulation have gotten smaller compressors. given the 1.6 amps, it's not going to be move more than about 500-700 btu/hr

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Yes, the rating on his freezer is surprising, and something I will keep in mind when I shop for my next one. 1.6A doesn't leave much reserve power. That is not a typical system, until now I guess. That is why I said something must be up with his system since others don't have similar experiences

Shockerengr said:

I did several tests with chillers when I was first setting up these system to confirm that stratification wasn't going to be a problem, and have probably 100bbls of brewed beer to back up that theory.

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I was talking more about radial strat post-active ferm in an internally chilled fermenter with no insulation. There are some guys on here who have done so thorough testing on this just to confirm their hunch. They also found some strange strat effects caused by the cone. From memory, it created an inversion layer type effect, or something like that, causing separate zones each with its own strat.

Shockerengr said:

There's no disagreement there, other than what each of us considers a large diff. I can run my system around 40-50 degrees below ambient, down to a wort temp of about 40-45. I limited more by the temps of the glycol on how low I can go than I am by the ambient temps.

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I would think that post-ferm, the ambient temp is the limiting factor, since you should be able to get very close to glycol temp with good insulation. The chiller rating limits this at some point if it can't keep up with the heat loss even with insulation.

Shockerengr said:

If I had my system in my house like the OP, and was only doing ales, I would suggest forgoing insulation for a glycol system with an internal chiller. The savings in energy aren't great enough to offset the cost of insulation for a 10-15 degree temp delta.

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This was part of the confusion on my part, as I originally thought this was in a non-climate controlled space based on my casual review of the pics, and the OP opening by talking about the Florida heat.

Shockerengr said:

I wouldn't worry about it just for crashing...the time frames are short enough to ignore the inefficiencies.

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I have didn't comment on the cost of the energy used mattering, except for the joke comment. I was referring mainly to optimizing system performance. It will just impact the crash rate, but probably not by much. He is limited to 32F for chilling, though, so it might have a bigger impact.

cwi said:

I was talking more about radial strat post-active ferm in an internally chilled fermenter with no insulation. There are some guys on here who have done so thorough testing on this just to confirm their hunch. They also found some strange strat effects caused by the cone. From memory, it created an inversion layer type effect, or something like that, causing separate zones each with its own strat.

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In practice with the systems I have, the only strat issues I've run into are where the coils are submerged and leave a layer on top. If there is any stratifcation remaining, it's not something that i've noticed.
I like running cold water, with a the coils up high to maximize the convective effects. So far, it's worked well.

cwi said:

I would think that post-ferm, the ambient temp is the limiting factor, since you should be able to get very close to glycol temp with good insulation. The chiller rating limits this at some point if it can't keep up with the heat loss even with insulation.

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In theory...yes. In practice, the heat transfer rate between fluids drops way off once you get inside 10 degrees delta T, enough that for me, it's not worth running the pump that long. I could get there, but I've found that it would takes about 3-4 times as long to get from 45-40 as it does to get from 65-45. The chiller keeps up as the glycol temps keep dropping, i'm just not transfering much heat. I could drop the glycol temp further down...but there's a point where I'd start getting concerned about causing beer slush.

I have checked to see what the effects on heat loss are, which is easy to do, and found that it's the dominant factor. That's why I'm not as concerned about the insulation used.

(It's easy to test, chill to a temp, shut the chiller off, and monitor how fast the temp rises..I calc'ed about 100-200btu/hr at 45 degrees.)