Fermentation Chamber- My Easter Present

Happy Easter!
This is my first post on the forum, and I'd like to thank everyone who contributes. I've learned a lot from all of you, so I figured I could share what I built with the few people who would understand how excited I am about this.

So I've been home brewing since about Christmas when my wonderful wife bought me the equipment I needed to get started, and I've completely fallen in love. About 4 weeks ago, I brewed up a hefeweizen and the temperature spiked to about 85 degrees, which made the house way to warm for my beer. I tried the T-shirt evaporation cooling method to no avail. I couldn't get the temperature down long enough consistently to keep the taste I wanted, and I ended up with a very very very fruity hefeweizen. So...I decided to build a fermentation chamber. Here it is.




The whole thing was loosely based on the plans found here:
http://www.wortomatic.com/articles/38DD-Mother-of-a-Fermentation-Chiller

I took the basic shape of the fermentation chamber in the link, but took off some height since I used a fridge to chill instead of ice.

For temp control used a $30 mypin PID controller. It was relatively easy to wire (even for a guy like me with no electrical knowledge) after I found a tutorial in a thread on this site. A thread which I can't find anymore, unfortunately. Here it is.



As far as results go, it'll hold Ale temperatures pretty easily, and I'm testing lager temperatures as we speak.

I mounted the compressor on the top of the chamber because I have very limited space in my storage unit

Welcome to the forum. I can't see any pics

Yeah. The pics didn't work. I'll try again.

Pics look good to me!

Very nice. Will it be big enough when the bug really hits?

Ahhh, now I can see them. Nice job!

kapbrew13 said:

Very nice. Will it be big enough when the bug really hits?

Click to expand...

I don't know if you noticed the amount of space in the storage unit, but I can't fit anything bigger in there.

Good job! And welcome to HBT.

Just after building this for cooling in the summer months, the weather dropped to lows of 30F and highs of 50F. Meaning, I may have to start heating my fermentation chamber rather than just cooling it. I was hoping to hold off on figuring this out until fall, but the weather did not help. Here's where I could use some help.

First, does anyone know of a cheap DC powered heat source that I could wire to the SSR to control the heating function. The SSR runs DC up to 24v and 20mA. I know it's designed to control a relay, but I'd like to avoid buying one.

Second, I figured out how to program the controller so it will turn the compressor on when it's too cool by setting it at Alarm 1. I'm not sure how to wire and program my controller so the SSR will switch on when the heat is too low. I'll put up a link to the manual with my PID controller, but I'll warn you...the manual is in very broken English.

http://www.agptek.com/software/PC5-2012-latest-manual.pdf

So here's how I programmed the unit. When alarm 1 goes off, it triggers the compressors and cools the chamber. The SSR is labeled "out". I'd like to get it to turn on my soon-to-be-purchased heat source.

Thanks in advance for the help.

It always bugs me a little bit when people refer to their temperature controllers for ferm chambers as "PID" since you aren't using the PID, you're using a basic on/off control. But that's just a little OCD coming out

Uziyahu said:

First, does anyone know of a cheap DC powered heat source that I could wire to the SSR to control the heating function. The SSR runs DC up to 24v and 20mA. I know it's designed to control a relay, but I'd like to avoid buying one.

Click to expand...

20mA at 24V is less than half a watt, there's no way you can get enough heating power with that. I'd buy an SSR and have it switch a few outlets so you can plug in, say, a light bulb and a small fan simultaneously. I have a similar box that I use to keep fermentors/bottle warm, and even with no proper insulation I can keep a fermentor at 75-80 degrees (ambient temp ~55) using a regular 60W light bulb that's cycled off a good portion of the time.

I'm an engineer and part of my job is setting up test stands in an electrochemical research lab, I haven't read through the manual for your controller but I've worked with lots of the lab grade Omegas.

In general I would avoid using the alarm outputs to control. Especially with a refrigerator, it will cause too-frequent cycling that'll kill the compressor. The alarm outputs I've used are either latched or unlatched (user selectable), if it's latched you have to reset manually and if it's unlatched the alarm shuts down as soon as the PV is within the "safe" range. You can't set a deadband on the alarm, so say you set the high limit to 70 degrees, at 70.0 the compressor will kick on, turn off at 69.9, turn back on a second later at 70.0, etc. The compressor won't last long doing that.

I'm not sure if your controller has two outputs and if they're both SSR outputs, if they are you can use two relays and run output 1 as cooling, output 2 as heating, etc. and use it as a dual stage on/off output. That way you can set proper deadbands on the on/off and give the two outputs slightly different setpoints so they aren't fighting each other.

Let me know if you need more help! I can check out the manual if you need me to. Either way this looks like a nice setup

I need to buy some insulation and make mine a proper heating box, I've been OK so far using a swamp cooler for cooling.

zachattack said:

It always bugs me a little bit when people refer to their temperature controllers for ferm chambers as "PID" since you aren't using the PID, you're using a basic on/off control. But that's just a little OCD coming out

Click to expand...

Sorry about the PID mislabel. Since I don't know much at all about this sort of thing, I just used the terminology I found on the box. I actually tried looking up what PID means and the explanation only confused me more.

In general I would avoid using the alarm outputs to control. Especially with a refrigerator, it will cause too-frequent cycling that'll kill the compressor. The alarm outputs I've used are either latched or unlatched (user selectable), if it's latched you have to reset manually and if it's unlatched the alarm shuts down as soon as the PV is within the "safe" range. You can't set a deadband on the alarm, so say you set the high limit to 70 degrees, at 70.0 the compressor will kick on, turn off at 69.9, turn back on a second later at 70.0, etc. The compressor won't last long doing that.

Click to expand...

I was worried about using the Alarm function for the compressor, but my controller gives me a range that the alarm works in once it kicks on. For example, I set the hysteresis on Alarm 1 for 1.5 degrees, so it allows the chamber to warm up to 1.5 degrees above my target and then cools it to 1.5 degrees below the alarm. Admittedly, I haven't sat around and watched the compressor much, but I've never heard it turn on for just a second and then turn off.

I'm not sure if your controller has two outputs and if they're both SSR outputs, if they are you can use two relays and run output 1 as cooling, output 2 as heating, etc. and use it as a dual stage on/off output. That way you can set proper deadbands on the on/off and give the two outputs slightly different setpoints so they aren't fighting each other.

Click to expand...

My controller has only 1 SSR output. Hopefully I'll be able to set that up so I can heat with that while I cool with the alarm function. Please let me know if I've misunderstood my controller and it's functions as I am completely and utterly new at this sort of thing.

It sounds like you've got it mostly figured out! I was just kidding around about the PID thing, btw.

I've never really used the alarm outputs for more than a safety alarm or an e-stop, but if you can set a deadband you should be all set.

The Omegas I've worked with let you set the alarm range as a relative value if you want, but I think that's just to trigger the alarm, not stop it. So for example if I set the high alarm to setpoint + 10 and my setpoint is 60 degrees, it enters the alarm state at 70 degrees but once it's at 69.9 again the alarm is disabled. So it's not really a deadband. Maybe yours is different? I'll check out the manual and post again in a minute.

How is the alarm output interfacing with the fridge? I'm just curious.

Haha wow, that manual's a real piece of work, I can't figure out how the alarm works. Mine come with a 70+ page manual! But I think you're right, there's that "section inside alarm" so you could use it as a deadband. As long as you keep an eye on it the first few times to make sure it's working the way you want everything should be good.

By interfacing do you mean how I wired it? If so, I sketched up a diagram and attached it to my post. Sorry about it being sideways and a little simplistic.

Oh ok, so it has a built in relay, got it. It says in the manual that relay's only good for 3 amps, so make sure you aren't drawing much more than that with your fridge! That's actually not a bad little controller for $20 or whatever you paid for it.

The controller's great. I checked out buying a thermostat and modifying it to run everything, but the cheapest one I could find was $20, plus I'd have to buy a relay and learn to solder. This was less money and much easier.

Well for someone that doesn't have much experience with wiring you did a great job.

Thanks! I did a lot of searching through many different forums to try to figure it out.

I did some searching and I might have found a heat source that would work. What do you think?
http://www.amazon.com/RoadPro-12-Volt-Portable-Stove-Black/dp/B00030DLEE%3FSubscriptionId%3D15HRV3AZSMPK0GXTY102%26tag%3Damznf-us-tbsearchsea-20%26linkCode%3Dxm2%26camp%3D2025%26creative%3D165953%26creativeASIN%3DB00030DLEE

or
http://www.amazon.com/RoadPro-RPSC-818-Defroster-Folding-Handle/dp/B000BHQ5JC/ref=sr_1_1?s=automotive&ie=UTF8&qid=1334263783&sr=1-1

They're made for cars cigarette lighters, so I'd need switch the cigarette lighter attachment with a wall power supply. I know I have a 9v supply at home but I could buy a 12v one. Am I crazy or would something like this work?

This is unclear from those poor instructions, but is there only one internal relay? From the instructions it looks you have the 3A "relay" option for both outputs/alarms, can you program it to use that? I know you mentioned before that you're stuck with the SSR output, is that right?

If the only option for that output is the SSR output (24V/20mA) then you need to buy a separate solid state relay to use it, that's what it's designed for. Those devices you linked to will draw much much more than 20 mA.

If you are able to use the second internal 3A relay, I would suggest just using a lamp.

Thanks for the advice. I'll just have to get a relay. I don't think I'll have to do that for a bit, though. It seems like the fermentation process is generating enough heat to keep everything where it's supposed to be.