ebay aquarium temp controller build

SSBrew - 728
Homebrew Talk - Beer, Wine, Mead, & Cider Brewing Discussion Forum

Help Support Homebrew Talk - Beer, Wine, Mead, & Cider Brewing Discussion Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
Although they look beautiful and hi-tech, I've seen many posts here where users vie against using submerged thermowells for T-control in these low tech environments. The large mass of the beer prevents rapid and timely feedback to the STC, or any other controller, thus the process will overshoot the set temp by many degrees. Then the same happens in the opposite direction. The result is you'll get large swings of temperature.

The trick is to find the best balance between response time and inertness of mass.
Therefore, most people find the probe taped tightly to the side of the fermentation vessel, about half way up the beer line, and insulated from the ambient air temps in the fermentation chamber with a wad of paper or a 1/4" layer of soft pliable packing foam to be the better system of controlling the temps more precisely to the target setting.
 
Interesting thought, I'm definitely still not 100% on how I want to mount that temp sensor. I don't particularly love the idea of taping it to the bucket, but I might be willing to test that with the thermowell installed and a secondary temp monitor inside to correlate the difference.

I'm curious if perhaps mounting the well close to the side of the bucket where the wrap is installed would prevent some of the 'overshoot' that is being observed. I noticed a significant difference in temperature by suspending the probe in the glass (test pic above) rather than have it float amid the liquid, so this certainly seems like a valid concern.
 
hunter306 said:
Interesting thought, I'm definitely still not 100% on how I want to mount that temp sensor. I don't particularly love the idea of taping it to the bucket, but I might be willing to test that with the thermowell installed and a secondary temp monitor inside to correlate the difference.

I'm curious if perhaps mounting the well close to the side of the bucket where the wrap is installed would prevent some of the 'overshoot' that is being observed. I noticed a significant difference in temperature by suspending the probe in the glass (test pic above) rather than have it float amid the liquid, so this certainly seems like a valid concern.
Click to expand...

Once at your set temp, there shouldn't be much overshoot unless you have a high hysteresis setting. It's mostly when the wort temp is significantly different than the set point that you'll see the overshoot, and it will be somewhat of a yo-yo effect with a decaying amplitude. This would mostly be when the wort doesn't start out at the set temp, or you ramp temps up towards the end of fermentation, or cold crash after fermentation. How much overshoot you see also depends on the thermal mass in the ferm chamber, and the specific heat and thermal mass of the fermenter. You'll see much less overshoot using a plastic bucket fermenter than you would with a sankey keg fermenter for example.
 
JuanMoore said:
Once at your set temp, there shouldn't be much overshoot unless you have a high hysteresis setting. It's mostly when the wort temp is significantly different than the set point that you'll see the overshoot, and it will be somewhat of a yo-yo effect with a decaying amplitude. This would mostly be when the wort doesn't start out at the set temp, or you ramp temps up towards the end of fermentation, or cold crash after fermentation. How much overshoot you see also depends on the thermal mass in the ferm chamber, and the specific heat and thermal mass of the fermenter. You'll see much less overshoot using a plastic bucket fermenter than you would with a sankey keg fermenter for example.
Click to expand...

I have no concrete facts on this except from what I've read posted by others, and applying some common sense.

The high hysteresis is caused by the time it takes for the beer in the center (or near the edge, if probe placed there) to reach the set temp. And the larger that difference, the longer that lag time, and the more it will overshoot. The temp of the beer near the outside will be a bit different from that in the middle of the fermentor, where the probe is. If that difference is negligible in repect to other brewing variations, then it would not be an issue.

Commercial breweries have cold jacketed fermentors, and that seems to work well. This is similar, for the fridge is our jacket.
 
Think it's possible to remove the light in a freezer and hook a computer fan up to the wire instead, then rig the fan to be on all the time?
 
IslandLizard said:
Although they look beautiful and hi-tech, I've seen many posts here where users vie against using submerged thermowells for T-control in these low tech environments. The large mass of the beer prevents rapid and timely feedback to the STC, or any other controller, thus the process will overshoot the set temp by many degrees. Then the same happens in the opposite direction. The result is you'll get large swings of temperature.

The trick is to find the best balance between response time and inertness of mass.
Therefore, most people find the probe taped tightly to the side of the fermentation vessel, about half way up the beer line, and insulated from the ambient air temps in the fermentation chamber with a wad of paper or a 1/4" layer of soft pliable packing foam to be the better system of controlling the temps more precisely to the target setting.
Click to expand...
The system you like (and which I also use) reads the thermal mass of the beer, as opposed to the temperature of the air. Therefore, thermal mass isn't the problem with the thermowells. As I've speculated before: if people using them are experiencing temperature cycling, I can only think of two reasons.

One is that the metal thermowell is conducting the ambient temperature of the surrounding air well enough to affect the probe, even though the end of the thermowell is in the beer. The other is that they're leaving the top of the thermowell open, and enough air is circulating to affect the probe. If that's the case, closing the open end of the thermowell ought to solve the problem.

When I built my fermenting chamber using a mini-fridge, I first tried taping the the probe to the inner side of the fridge, and leaving it exposed. My setup cycled endlessly between heating and cooling. Then I tried dropping the probe into a tea kettle of water. It slowed down the cycling, but didn't stop it.

Taping the probe to the side of the carboy, then covering it with foil-sided bubblewrap insulation and taping all the edges securely, stopped the cycling. I normally don't overshoot my set temp by more than .1*C.

That setup works so well that in my opinion, any discussion of thermowells should remain theoretical anyway....:)
 
Beernik said:
Think it's possible to remove the light in a freezer and hook a computer fan up to the wire instead, then rig the fan to be on all the time?
Click to expand...

The dome light inside my keezer runs on 115 volt AC line voltage, and I suspect that is typical. Otoh, "computer fans" almost always run on DC - 5 or 12 volts. Be sure to get a compatible fan. Also, if you are using an external controller and don't mod the dome light wiring, the light won't go on with the lid open unless the compressor is running...

Cheers!
 
day_trippr said:
The dome light inside my keezer runs on 115 volt AC line voltage, and I suspect that is typical. Otoh, "computer fans" almost always run on DC - 5 or 12 volts. Be sure to get a compatible fan. Also, if you are using an external controller and don't mod the dome light wiring, the light won't go on with the lid open unless the compressor is running...

Cheers!
Click to expand...

Yeah, maybe I'll just splice it to an old cellphone charger. They convert AC to DC and I have a bunch of old ones.
 
I finally got my setup wired and built. I added a small chamber to the top of my ferm box (2" extruded polystyrene a la SOF, but smaller) for 1/2 gallon ice bottles and put a fan at one end and a bunch of 1" holes at the other. I got a DC 12V wall wort from the thrift shop as well as a power cord, a light fixture for my heater, and a Chimay Chalice for $4. We'll see how quickly this set-up will drop the temp on my Trippel to 50.

Foor wiring a fan from the light, it will only come on when the temp controller is powering the cooler, and when the door is open. You could short the door swith, though, so it thinks it's always open (unless it shuts off the compressor with the door open).
 
Beernik said:
Yeah, maybe I'll just splice it to an old cellphone charger. They convert AC to DC and I have a bunch of old ones.
Click to expand...

Good idea, I'm not a proponent of running 115VAC fans inside a keezer.

On my keezer the feed to the dome light runs externally up the back to a three pin plug/socket feed-through connector, and it would be trivial to remove the line power connection at the compressor end and stick a wall wart output on it. That would allow you to plug the wart directly in a wall socket/extension cord and bypass the external controller.

Once you've done that, if you don't mind removing the lid liner, you could likely replace the 115VAC dome light bulb with a 6V or 12V version (mine is a pretty basic looking bayonet bulb that I'm sure could be subbed with a DC bulb) then splice in a parallel line connected before the mercury switch to run a pc fan or two. I'd probably go with a 12V 1A wall wart to run all that, USB/cell phone chargers are typically 5~6 VDC at an amp or less and might not be able to keep up.

Or you could just run a completely separate DC circuit through the back edge of the lid and leave the original wiring alone. That's what I did...

Cheers!
 
hunter306 said:
The cable is all 14ga in my build pictures. :mug:
Click to expand...

I generally use 16 ga cable and 14 ga wire for my builds. If someone wants one with bigger gauge I do it, but I don't like bending the 12 ga wires around. A 16 ga cable is rated at 13 Amps while the controller is rated at 10.
 
I believe the relays are rated for 220v @ 10amps, which means they should be able to handle more than 10a @ 120v.

14ga is rated for 15a @ 120v.
 
After some trouble with my chamber addition, I think I have the kinks worked out. I caulked the corners and re-did the door and I think it's gonna get me down to 50 for the lager stage on my tripel. Maybe I'll thow up some pictures.
 
Beernik said:
Think it's possible to remove the light in a freezer and hook a computer fan up to the wire instead, then rig the fan to be on all the time?
Click to expand...

You could always add a second STC 1000 that runs just the fan. I've done that on my side by side kegerator to even out the temps on both sides. The probe goes on the "freezer" side which tends to be the colder side, and is connected to the heat relay. The fan pushes cold air to the "fridge" side until the freezer side is at the desired temp, then the fan shuts off. This delays the compressor kicking in until the other STC 1000 (probe on the fridge side hooked up to the cold relay) reach the upper limit and the cooling cycle starts up.
 
This is kind of what I'm thinking. I'll add a always on plug to my project box and splice a computer fan to a cellphone charger and screw the fan to the top of the freezer.
 
Had a problem with mine this weekend. It quit turning on the cooling relay. This coincided with a move to a new house. I had a backup controller I threw in there real quick, but my 18 gallons of APA brew went about 20 hours Uncontrolled about 10°C too hot!
 
I ordered from mixtea about 4 months ago, did not receive the item and was promised either a refund or another item, at first I asked for another item , he said he sent it, never came, so finally I asked for a refund, never got it, can't do anything now because more than 3 months have passed (ebay and paypal have that rule). I have the phone number provided by ebay so all I can do is call and push for a refund. I will never order anything from this person or China again. Be warned.
 
mrbean said:
I ordered from mixtea about 4 months ago, did not receive the item and was promised either a refund or another item, at first I asked for another item , he said he sent it, never came, so finally I asked for a refund, never got it, can't do anything now because more than 3 months have passed (ebay and paypal have that rule). I have the phone number provided by ebay so all I can do is call and push for a refund. I will never order anything from this person or China again. Be warned.
Click to expand...

That's deplorable. And we all know how it's easy to get caught up in such a bad transaction, together with terrible communication, false promises, lag times, "transit time," and a bunch of other antics, the 3 month period lapses before you realize it. One more reason to avoid those kind of purchases. It can be very hit and miss.

You can buy these from US sellers on Amazon for the same price or less.
I got mine for $18.00 each, a few months ago, on Amazon (Elitech/Sain Store).
 
ParadiseBeer said:
here is a quick outline of my two plugs, switch and lamp light control unit. all done in a 7X5X3 box. quick and easy.
3060-two-plug-switch-light-control.gif
Click to expand...

I want to do basically the same thing. Where can I get the "blocks" and what are they called at Radioshack?

thanks:mug:
 
Or buy a 110AC relay. Connect your output from the controller to the relay toggle position. Put the power on one side of the relay and on the other side Alice the wire to go to the fan and the AC. Probably a good idea to also put a fuse before the power connects to the relay, just in case. I've done a similar thing but am able to turn on the fan for both hot and cold. My drawing might be hard to read.

ForumRunner_20131114_165501.jpg
 
Temperature Controller STC-1000: Do not order from mixtea on ebay. I ordered and paid for mine four months ago, many messages back and forth and now nothing, no product and no refund and no more messages. I got ripped off, be warned.
 
I was sent the wrong one (220V instead of 110V, even though that's what was advertised on the eBay page) from Hong Kong. I asked for a full refund, with the intent of sending it back. Instead, they gave me a partial refund ($12 of the $18 I paid) and let me keep it. I ordered a 110V from the states next...

Which reminds me... Does anyone need to buy a 220V STC-1000?! I'll just sell it for cost ($6 difference) plus shipping (which I assume would be to Europe or somewhere else they use 220V) - not sure how much shipping would be...
 
I misordered one from Amazon - a 12V AC version instead of a 110V version. Amazon makes returning things like that easy, although I did have to pay the return shipping fees. Considering it was my error, I have no complaints. I have gotten 3 more of the right kind since then.
 
FatsSchindee said:
[...]Which reminds me... Does anyone need to buy a 220V STC-1000?! I'll just sell it for cost ($6 difference) plus shipping (which I assume would be to Europe or somewhere else they use 220V) - not sure how much shipping would be...
Click to expand...

I'd find out what the shipping would be to say London, because I suspect eating the $6 you're out will be the economical option.

In any case, there's a thread lurking around HBT on how to replace the STC-1000's internal transformer to convert from 220 to 110vac. It's not the all-time prettiest solution but if it ends up in a project box or poking through a keezer collar nobody's going to notice the hack job on the original case...

Cheers!
 
day_trippr said:
I'd find out what the shipping would be to say London, because I suspect eating the $6 you're out will be the economical option. In any case, there's a thread lurking around HBT on how to replace the STC-1000's internal transformer to convert from 220 to 110vac. It's not the all-time prettiest solution but if it ends up in a project box or poking through a keezer collar nobody's going to notice the hack job on the original case... Cheers!
Click to expand...

Not a bad idea. I have the first one in my chest freezer fermentor, but if I ever switch to kegging (which I'm sure I'll do at some point down the road), I'll want one for my keezer/kegerator too... Thx.
 
I'm sure this has been asked before but I couldnt find much in the way of a definitive answer. For those of you using a light bulb in a paint can as a heating source, is that method safe? I bought the stuff to make this and then started to question whether this is safe since there will be moisture inside the freezer where the paint can goes.

Any thoughts? Also, for the power chord to the paint can, do you just run it under the lid of the freezer and does this allow much cold/hot air to escape?
 
cincybrewer said:
I'm sure this has been asked before but I couldnt find much in the way of a definitive answer. For those of you using a light bulb in a paint can as a heating source, is that method safe? I bought the stuff to make this and then started to question whether this is safe since there will be moisture inside the freezer where the paint can goes. Any thoughts? Also, for the power chord to the paint can, do you just run it under the lid of the freezer and does this allow much cold/hot air to escape?
Click to expand...

The seal around the lid gives enough to let the cord under and yet still forms a good seal around it - I don't see it letting much air/temp out.
I had a similar thought about the moisture, and use DampRid inside to help with that. It helps some, but there is still moisture that builds up. One thing I noticed is that it caused a rust ring around the bottom of the freezer where it was sitting, so I put an old towel down underneath it now... Put something underneath it first - learn from my mistake!
 
FatsSchindee said:
The seal around the lid gives enough to let the cord under and yet still forms a good seal around it - I don't see it letting much air/temp out.
I had a similar thought about the moisture, and use DampRid inside to help with that. It helps some, but there is still moisture that builds up. One thing I noticed is that it caused a rust ring around the bottom of the freezer where it was sitting, so I put an old towel down underneath it now... Put something underneath it first - learn from my mistake!
Click to expand...

Thanks for the info.
 
glugglug said:
Has anyone used a strain relief for the temperature probe cord? If so, what size and where can I pick one up?
Click to expand...

I have built a dozen or so of these. I just use a small hole in the box to pass the probe cord through, and tie a simple knot in it on the inside of the box. I then pull the cord from the outside to snug the knot up to the hole. Works perfectly.
 
glugglug said:
Has anyone used a strain relief for the temperature probe cord? If so, what size and where can I pick one up?
Click to expand...

I picked mine up at Home Depot. I think it was 3/8th but I just got one that fit the cord.
 

Similar threads

B
eBIAB PID Controller Wiring Diagram - Feedback Requested
Replies
14
Views
1K
beerisambrosia
B
W
Power distro
Replies
1
Views
337
whoaru99
W
kotamoore23
120/240v DIY PID Controller Help
Replies
17
Views
1K
whoaru99
W
L
Building a potentiometer controller
Replies
25
Views
1K
doug293cz
doug293cz
A
BrewPiLess esp32 Build
Replies
4
Views
561
DuncB
D
SSBrew 300

Latest posts

Back
Top