ebay aquarium temp controller build

Not sure just found this setup when searching and liked the idea of using the 3 gang box with decora plate.

 

Just finished mine this weekend. Took quite a bit longer than I thought it would, but projects always do. Told SWMBO I'd be working on this for about an hour or so, but shopping + wiring took me about 5.5 hours hehe. Here it is!



To be fair, the last hour or so was me fretting the cooling power supply wasn't working (thus, disassembling and testing), but it turns out I'm a moron and I forgot that the cycle delay stopped the cooling outlet from being powered until the set-time passed. Doh! Works fine and I need to retract my email to mixtea :/

8x6x3 box from RadioShack, with the outlet in the back. Very basic build, no indicator lamps or anything. I don't really see the point when the STC1000 already displays when it's heating or cooling. I'm most pleased about the rubber grommets around the cables as they exit the box... make everything look professional and fancy! Power cable goes out the back (which you can't see), and that's the temperature probe in the lower left of the photo.

Making one of these is like a rite of passage for a brewer. Happy to join y'all!

 

I was freaking out that my compressor went out because the controller was showing work, and the temp was up. Spent a ton of time with thermometers and tinkering before looking up and noticing the fridge was on its defrost schedule. Whoops.

 

I got my setup finished today. Currently have two gallons fermenting inside. Everything seems to be working however it overshooting the cooling by alot. F1 is set to 17.8 and F2 is .5. The probe is taped to the side of the youngest carboy, insulated with some cloth.

The cooler turns on at 18.3 and then off again at 17.3. The issue is ambient temp in the cooler reaches to 12.2 before the carboys temp reaches the cutoff. This causes the carboys temp to continue to drop causing a large variant in fermenting temps.

Any suggestions?

 

What are you using as a heat source?

If its a brewbelt type deal I could see it taking a while to overcome the cold, try using a small personal heater or something that would warm the air more quickly.

 

I would tighten the cutoff temp band to no more than 0.3 degrees.

I would also make sure the probe is well insulated from the ambient temps. I use a combination or insulating tape (used to keep outdoor pipes from freezing) and reflectix and that seems to work quite well.

Place your probe halfway up the level of liquid for the best approximation of the average temp in the fermenter.

Make sure you have a fan circulating the air.

Also remember a new fermentation pumps a lot of heat into the beer and is harder to cool down.

And last, relax, don't worry.....

 

Thanks for the suggestions. I found that I had freezer temp control was set to the coldest setting. Turned that down and it smoothed the transitions out a lot more. Also set the cutoff temp to .3 degrees. I am currently not using any heater inside. I will put a fan in though to circulate the air some.

Too bad you cant have the cutoff temp being measured by a second probe because by the time the fermenter reaches the cutoff the ambient temp is cold enough to keep driving the fermenter temps down.

 

I think if you stood there and watched the temp for another few minutes, you would see it climb back up once the ambient diff was absorbed. You are not seeing ferm temps, but a combination of ambient and ferm. The cloth you are using for insulation doing almost nothing to insulate the sensor from ambient, so you are seeing mostly ambient during the cooling cycle. Even closed cell foam has a hard time not being influenced by ambient.

This influence is actually helpful in shutting of the cooling a bit early. Although, shutting off early isn't really that important because the amount of thermal mass of the ambient air, freon, walls, etc. is fairly small compared to ~50lbs of beer, especially if it is active and generating heat, unless your chamber is oversized for the small batch sizes you are doing. A small computer fan going full time will help with temps.

You can also put some additional thermal mass in there, which you already have with your second carboy. You do have to watch out using a late stage beer as a thermal mass because its temp will be colder than the setpoint for the active beer. This could stall the cleanup of the inactive beer.

 

These are 1 gallon batch sizes so, it is a 5cu freezer and only 2 gallons of liquid. Maybe I will add another couple of gallons of water off to the side.

The first beer is 2 weeks and waiting on the third week before bottling. The newest is 1 week old, waiting another 2ish weeks. I plan on keeping the carboys in use for most of the time. So there will (should) be an active fermenting one and one that is cleaning up. My understanding is that temp should remain consistent through the fermenting and cleanup process.

So maybe the best option for me would add a bucket of water and drop the temp controller probe in it. Then it would be keeping that thermal mass temp steady while the other two do their thing. Then I just need to watch the actively fermenting one. Should I place the actively fermenting on in a bucket of water to swamp cool it? Or would the fan circulating the air be enough.

 

You can't control 2 things with one controller and one control input. You might look into second controller and a DIY ferm wrap for the inactive one, or even for both, and another controller to keep the freezer ~10F colder than ferm when active. The heat wraps should provide more consistent temps, since there will be virtually no overshoot.

Since you are doing such small batches, using a swamp cooler setup in the freezer might give better results, but you still need another controller for the inactive batch if you care about its temp. Give each their own bath, and maybe use an aquarium heater on a controller for the inactive one. Control becomes more complex with the bath, but maybe not enough to matter. Shouldn't cost you anything to try it, as long as you have a tub sitting around. Personally, I would just brew larger batches. Going from 5 to 15 gallons adds some issues, but going from 1 to 5 gallons shouldn't add that much more work, with more beer to share. Your temp control issues will largely disappear, except for the 1 controller per vessel issue.

 

I've looked for two days and cant find a good wireing diagram with a fan on all the time for my coffin box if any one can help I would be grateful thanks

 

This worked for me

 

Just finished my controller build. This site rocks.

 

thanks but its it my garage and gets down to freezing at times so i need the heat side too any thoughts

 

Just wire a second duplex next to the switched one. Run a hot, ground, and neutral from the first wire nut when the extension cord enters the project box.

 

Thanks that should work

 

This is what I was thinking. Just get a little bit bigger project box. Note: I am obviously no electrical engineer.

 

That is perfect thanks

 

This is the fan I got i bought four of them will they work

 

Any old computer fan will do. Just find an old cell phone charger that has the same output voltage and splice them together. Looks good.

 

i used a UL listed box for a professional look.

 

Finished mine up Sunday. Looks good. Can't wait to get my freezer from the garage to the basement to ferment some beer!

 

cant one of the wire nut take all the hot wires and eliminate the other one and thanks that is what i wanted to hear :rockin:

 

Yeah, just drew it that way to look simpler. As long as you have the right size wire nut that would be fine.

 

Thank you Pablo

 

Do any of you fine gents happen to use your temp controller with a mini-fridge? If so, I'd love to know the make and model.

I'm wanting to build up one of these temp control units to regulate a mini-fridge capable of holding a 6.5 gallon better bottle w/blowoff tube/bucket, and I don't have the slightest idea which fridge to begin looking at, since they all seem to have weird bumps or ledges to make things difficult.

 

I have 2 on minifridges. One will only hold a 3 gallon BB. The other will hold 5 and 6 gallon BBs. I did have to trim the door shelves down to make it fit though. Look for units that spec a "full floor." It probably won't be advertised, but will usually be in the specifications list on your big box website.

 

Sanyo 4912M with the door trimmed works well, though I think it's discontinued. You just want one like this with a flat floor, like jeepin said.

 

Or get the cheapest one you can find on Craigslist and build a chamber from it. You could then fit 2-3 BBs with ease.

 

Make sure you inspect it thoroughly if you do. There was a crazy thread here last week about a guy whose CL chest freezer ended up full of bugs. Nasty.

 

Yeah, I'm digging the chamber idea, but I'm in a pretty small apartment, so space is at a premium. That's why I'm hoping to find the smallest mini-fridge that will get the job done.

 

You could get something like a 5 or 7 cu ft. chest feezer and modify my ferm chamber idea to your likings. (see my sig line for link) If you could fit just one malt drum in there, you could ferment 11-12 gallons of beer in pretty much the same footprint as a 6 gallon carboy. Why waste the head height in a ferm chamber?

 

I picked up this tiny ceramic heater today at Walmart. It was like $14.82 at the store.
http://www.walmart.com/ip/Lasko-Products-My-Heat-Personal-Heater/16503222

200 watts, 2 amps

I'm hoping it works out well for my ferm chamber.

 

It works for mine.

 

I'm using a couple of the Visanni 52 bottle wine coolers (search this DIY forum). Just adjust the screw in the stock controller counter clockwise and then plug into your ebay controller. I have a 12" wide heat tape attached with velcro to one of the side walls for heat.

 

i use a hair dryer i got from dollar general for 4 dollars. on the low setting it draws 3 amps. it only runs for 2 or 3 minutes to warm up my fridge by 3degC, controlled by a stc 1000.

 

I did this, using SIPs (Structural Insulating Panels) and it works great. But it more than doubled the floor space used by my GE mini-fridge. I got the mini from Craig's List for $50.

Make sure when you buy it is a real refrigerator with a condenser so it can lager.

 

Don't they all have condensers? I know some are exposed on the rear and others are built into the sides and top.

 

Just wanted to join this thread as I am getting ready to build my keezer with a new GE 7.0 Cubic feet freezer from Sams ($198).

Frys electronics has Sanyo 4912Ms for about the same price if you do in store pickup.

My wife suggested the 4 kegs on tap vs the 1. God bless her heart.

Also thanks for posting about these controllers. For that price ($22 shipped) I bought two. I just hope there isn't a 220v that they are shipping because it didn't specify on the feebay ad. (http://www.ebay.com/itm/320938934030?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649) <~~the two I bought look like the ones everyone else using.