Reccomend a thermostat, please

K, I have one chest freezer as my keggerator using a Johnson Controls Thermostat. Not sure the model, but it is the one that has a 4 degree variance.
I do have another chest freezer that I want to use for fermentation until I can get an upright freezer. Some say that a 4 degree variance is not good enough for fermenting (although I am sure the temp inside the fermentor likely only varies by a degree or two)

What is a good thermostat for a fermentation chamber, I will be doing ales and lagers in it.

Am I right in assuming the temp of the wort will not vary as much as the air in the chamber?
A, there will be residual heat from fermentation,
B, liquid holds heat longer than air,

My belief is that is my compressor kicks in at let's say 60 degrees and brings it down to 56, my wort should always be in the 57-59 degree range???

Am I right in assuming the temp of the wort will not vary as much as the air in the chamber?
A, there will be residual heat from fermentation,
B, liquid holds heat longer than air,

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Yeah, I think you are thinking correctly. The air might sway 4 degrees but the liquid won't.

Tape the sensor to the outside of the fermenter and it will moderate the the temp swing a bit.

BargainFittings said:

Tape the sensor to the outside of the fermenter and it will moderate the the temp swing a bit.

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I may brew two or three at a time though... Maybe I could stick it between fermentors.

Anyone using this one?
http://www.homebrew-supplies.ca/via...ture+control&search_category_id=0&item_id=589

I've got one of the Johnson A419 Digitals on my keezer. You can adjust the variance down to 1 degree. Very accurate controller. $67 to the door.

http://www.energysavingcontrols.com/Search.aspx?k=A419ABC-1C+

BendBrewer said:

Yeah, I think you are thinking correctly. The air might sway 4 degrees but the liquid won't.

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+1 The temp variance of the beer will be negligible. A 3 or 4 degree swing in the air temp won't cause any problems whatsoever.

JakeTheHopDog said:

I've got one of the Johnson A419 Digitals on my keezer. You can adjust the variance down to 1 degree. Very accurate controller. $67 to the door.

http://www.energysavingcontrols.com/Search.aspx?k=A419ABC-1C+

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How was it to install? do you need to hard wire it? or just plug in your freezer?

I'll check that one out, living in Canada sometimes makes ordering these a PITA. If they ship by USPS, no big deal, if they use a courier, I get nailed with duties and brokerage fees, not to mention the exchange (which these days is pretty good) I have purchased $35 items that were $75 to my door.

I have the Ranco and am happy with it. I don't think you can go wrong with Ranco, Love, or Johnson. I'd go digital though, just because it makes it alot easier to adjust the temperature often for fermentation, diacetyl rest, crash cooling, etc..

I got this specific one from Climate Doctors. Their prices are better than most places (they're also an amazon retailer)
http://www.climatedoctors.com/Items...ETC-111000 Microprocessor Temperature Control

billc68 said:

Am I right in assuming the temp of the wort will not vary as much as the air in the chamber?

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I'd say "no" or "it depends." If the outside air is warming the interior of the fridge, the air inside the fridge may warm faster than the beer. If the beer is warming the air inside the fridge, the beer will necessarily be warmer than the setpoint.

A 4ºF hysteresis is fine for a kegerator, not good enough for controlling fermentation.

billc68 said:

How was it to install? do you need to hard wire it? or just plug in your freezer?

I'll check that one out, living in Canada sometimes makes ordering these a PITA. If they ship by USPS, no big deal, if they use a courier, I get nailed with duties and brokerage fees, not to mention the exchange (which these days is pretty good) I have purchased $35 items that were $75 to my door.

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They do ship to Canada. It was pretty easy to wire. Used an extension cord. End up with a line to plug into the wall, and a line to plug the freezer into. Temp probe is nice too as its wire, not the copper coil like the non digital model.

So basically you do nothing to the freezer but plug it in to the controller and cut an extension cord in half and wire to the controller.

Yes, nothing done to the freezer. Plug it in, drop the temp probe in the freezer, shut the lid, set your controller settings, and that's it.

944play said:

A 4ºF hysteresis is fine for a kegerator, not good enough for controlling fermentation.

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I strongly disagree. You can easily check this with a separate thermometer probe in the fermenter. I have done this and the temperature of the beer changes only a fraction of a degree and probably less than that. I'm sure there is some convection action going on inside the fermenter as the beer temperature will never be completely uniform throughout the fermenter. A very active fermentation will generate some internal heat. I think we are all aware of that fact, but this can be easily mitigated simply by turning down the set point 5 or 6 degrees. I always set it low at the start of fermentation and raise the temp as it slows. I pitch the yeast when the wort is at the very low end of the suggested temp range and slowly raise it as the ferment progresses.

The air temp swings in the fermentation chamber can be quite large without much affecting the huge thermal mass of the beer. The beer temp changes only very slowly.

Now can the mentioned thermostats be used for heat as well?
I have a small room in my garage with electric baseboard heat, I was using it to store photo gear but would now like to brew in there. I am thinking in the winter I can set the heat to 32-60F depending on what I am doing as long as it is colder outside than in, we should be good BUT the thermostat I have only goes as low as 50F.

This one http://www.northernbrewer.com/brewi...-control/johnson-refrigerator-thermostat.html was recommended to me by someone at Wyeast. I am getting ready to purchase one as well.

billc68 said:

Now can the mentioned thermostats be used for heat as well?
I have a small room in my garage with electric baseboard heat, I was using it to store photo gear but would now like to brew in there. I am thinking in the winter I can set the heat to 32-60F depending on what I am doing as long as it is colder outside than in, we should be good BUT the thermostat I have only goes as low as 50F.

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Yes they can. Even the Johnson analog can be used for heating as well as cooling. This does require you to remove the cover and switch the hot lead to the opposite terminal on the internal double throw switch, but that takes all of about two minutes to do. The digital A419 Johnson requires you to remove the cover and move a jumper pin, but again, it's not a big deal. There are a few much older Johnson analog controllers floating around that have a single throw internal switch so it won't work with those, but they are relatively rare. So rare that I have never actually seen one. I did read that someone did have one, so they must exist. If you read the specs or users manual for any controller, it should provide details on this stuff. You can find the manuals on the Johnson web site. Don't know if it's the same for the others.

Catt22 said:

A very active fermentation will generate some internal heat. I think we are all aware of that fact, but this can be easily mitigated simply by turning down the set point 5 or 6 degrees. I always set it low at the start of fermentation and raise the temp as it slows.

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By saying this, you are agreeing with me.

944play said:

By saying this, you are agreeing with me.

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Not really. I'm saying that a 4 degree swing in the air temp in a fermentation chamber is not a problem. The fermenting beer temp will not swing anywhere near that much. You stated that this much variance was not acceptable. Seems to me our opinions are the opposite, not the same. Did I somehow misunderstand? I do that a lot.

I'm saying the controller, if it's doing its job, should need no intervention to keep the beer at the set temp.

You're saying to keep the beer at your desired temp, you have to set the controller to several degrees under that during active fermentation.

We're both saying 4º is too big a differential, just in different ways.

944play said:

We're both saying 4º is too big a differential, just in different ways.

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Catt22 said:

I'm saying that a 4 degree swing in the air temp in a fermentation chamber is not a problem.

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motobrewer said:

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Me too!

I just set up a chest freezer with a Love controller by Dwyer Instruments.

http://www.dwyer-inst.com/Products/Product.cfm?Group_ID=622&sPageName=Ordering

I used the TSS2-2100 and TS-51 probe. This gives you dual outputs and dual setpoints. I will need to use the second output for heating come winter. I have the probe in a bottle of water to try to regulate temp swings. Just started using it but it seems to work well.

The TS-51 probe is not waterproof. I had a piece of copper tubing that I cut to length, stuck the probe in and injected silicone caulk into one end until it squirted out the other. The probe has been submerged for several weeks now with no problems.

Let's take the interior of the fridge to be a closed system that we can remove heat from by switching on the compressor. Let's add heat by fermenting some sugar.

The fridge airspace will not reach the setpoint until the ferment temp is HIGHER than the setpoint. It will be higher until it's no longer actively metabolizing; we don't know exactly how much higher since we're controlling the air temp not the beer temp.

I want to control the temperature of the beer, not the air.

you may want to control beer temp, but you are controlling air temp.

a 4 degree deadband (hysteresis refers to the fact that a thermostat control system state is dependent on its history, not that it has 4 degrees of....hysteresis?) is adequate for a normal size box, since the time constant to bring the cooler air temp back to target temperature is low (i have a roughly 6' x 3' x 2' keezer, mine takes less than a minute i believe).

if you had, say, a 2,000 square foot freezer, i would agree that 4 degrees is too wide.

I'm done here. Have fun!

Anyway, I bought the Johnson controller locally (at a control shop) and I also bout a digital non programmable thermostat for the room it will be in. I will have to go without a probe in my beer as i want to brew 2-3 at a time (or however many can fit in the freezer.

The room thermostat will only go down to 4.5C (or 40.1F) so I can lager in there but at the higher end of the lagering range. But I could always put the lagers in the fridge

Any time you're measuring the air temp and not the beer temp, an actively fermenting beer will be warmer than the measurement, but we don't know by how much. This is the uncertainty that I want to eliminate, and the controller should automate that for me.

the controller can't possibly automate that for you unless it knows the heat transfer rate of the beer, which is nowhere near steady-state.

you could buy a thermowell and measure beer temp. It would be more accurate but still lag air temp (again, not by very much).

trying to control beer temp while using air temp as your feedback will always induce noise in the control signal.

a thermostat is a pretty simple device; if you want to get into more advanced control algorithms which use a variety of inputs, you'll have to go to some other type of controller.

EDIT: I just read thru this and it sounded negative to thermostats, lol. My summary is that on/off control is a perfectly good control strategy for fermenting beer. Coincidentally, I have a fairly powerful controller on my keezer, capable of a couple-10 inputs or so and trending/logging capabilities. If I had a thermowell I'd record the air temp and beer temp of the oktoberfest i'm making sunday. maybe I still will and just do one air temp and tape+insulate another probe to the side of the carboy.

op, sorry for the jack, looks like you're sorted.

I love reading threads that go somewhat off topic... still learning!

billc68 said:

Anyway, I bought the Johnson controller locally (at a control shop) and I also bout a digital non programmable thermostat for the room it will be in. I will have to go without a probe in my beer as i want to brew 2-3 at a time (or however many can fit in the freezer.

The room thermostat will only go down to 4.5C (or 40.1F) so I can lager in there but at the higher end of the lagering range. But I could always put the lagers in the fridge

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which johnson controller? same one in the link provided earlier? also, how much $$$ and whereabouts you get it? i've been tossing up the idea of building one and looking for the easiest/economical way to convert to a keezer.

Jmac00 said:

which johnson controller? same one in the link provided earlier? also, how much $$$ and whereabouts you get it? i've been tossing up the idea of building one and looking for the easiest/economical way to convert to a keezer.

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Kerr Controls carries them, there is likely one in NB, Yes I got the one posted earlier.
Kerr Controls is a wholesaler so you will likely need a friend in the plumbing and heating business, or refrigeration business or in my case an electrician to buy it on their account.

Worst part is I don't know how much it cost as they wouldn't tell me (knowing there may be a mark up on it) but I will be seeing my buddy next week to pay for it and it will likely be aroun $100 CDN or just under. seems high but if i paid $52 US plus UPS fees and taxes at the border, it is probably cheaper.

Sorry to hijack your thread Bill, but this is kinda on the same topic. I've seen these temp controllers and there's a place local. They look like the johnson ones. On the page linked, just curious what's my best option for my keezer project. i'm thinking the cheaper one, GGS1UHH4 ?? Any reason why this wouldn't work?

https://www.acklandsgrainger.com/images/catalog/1266.pdf

Jmac00 said:

Sorry to hijack your thread Bill, but this is kinda on the same topic. I've seen these temp controllers and there's a place local. They look like the johnson ones. On the page linked, just curious what's my best option for my keezer project. i'm thinking the cheaper one, GGS1UHH4 ?? Any reason why this wouldn't work?

https://www.acklandsgrainger.com/images/catalog/1266.pdf

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Looks like it is for heating, which I assume means it switches on when cold and not the other way around.
Noble Grape in Halifax sells the Johnson for about the same price, they can ship it to you or to their Fredericton store. If you can time it right, you can get it sent to Fredericton with no shipping if they have an order going anyway.

billc68 said:

Looks like it is for heating, which I assume means it switches on when cold and not the other way around..

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Says its for heating and cooling, i have an old catalog, and that same part number says cooling only in that one, online catalog says both...guess i'll keep looking....knew about the one at noble, but i'm trying to keep cost down as its an old chest freezer and it was free...don't wanna dump alot of $$ into it.

billc68 said:

Noble Grape in Halifax sells the Johnson for about the same price, they can ship it to you or to their Fredericton store. If you can time it right, you can get it sent to Fredericton with no shipping if they have an order going anyway.

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He tacks on shipping charges when you go pick up your stuff. I'll have it mailed to me directly from halifax before i go to him.

Just stick the sensor between the fermenters. 4 degree hysteresis is fine because that means plus or minus 2 degrees of target temp. Easy as that. RDWHAHB.

BTW, it's recommend, not reccomend.

EarthBound said:

Just stick the sensor between the fermenters. 4 degree hysteresis is fine because that means plus or minus 2 degrees of target temp. Easy as that. RDWHAHB.

BTW, it's recommend, not reccomend.

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wrong. it's either +4 (in cooling cut-out mode) or -4 (in cooling cut-in mode)

BTW, that's not the correct usage of the word "hysteresis"

I apologize. You obviously know what you're talking about, so please explain to me what hysteresis is and what you mean by cooling/cut-in and cooling/cut-out modes. Thanks!

i just got a johnson a419 and am curious, too, about whether it should be set for cut in or cut out for fermenting. I understand the difference between the two, but didn't know if one mode was better for fermenting than the other.

thanks