Fermentation chamber heating relay

So what I basically have built is a "mother of a fermentation chamber".
However, I was looking to heat this thing during the winter when temps can drop pretty low at night.
I have modified a digital thermostat to turn on my circulation fan.

So my thoughts would be to purchase a small heat emitter lamp (that doesn't put out light), or a small heating pad and put that in one of the lower chambers where it'll get some decent airflow.

However, I'd like to wire my thermostat to a relay so that my 12vdc power supply can also flip a relay to turn on the heating element.

I'm assuming I need a 12vdc SPDT 120vac relay in the normally open position? However I have no idea where to find one of these. More less something that I can wire in a project box or the likes to keep the wire mess neat.

Any ideas?

ebay is loaded with SSR's. Many of them are trigger-able with a large voltage range which includes 12 volts.

an SSR for this application is a bit overkill. they aren't exactly cheap and depending on the current can require a heatsink (but probably not for this application).

A better idea would be to get a mechanical relay form RadioShack or your local DIY electronics store. Get one with a 12Vdc coil and contacts rated for 125V or higher and a current rating higher than what your heating element will draw.

Yes, one with NO contacts is what you want, but most off-the-shelf relays have form C contacts (a open and closed position that switch upon engergizing the coil)

Excellent, I'll head over to RadioShack and see what they have.
My next question was actually going to be if I needed a heatsink for an SSR, but I think the cheaper\simpler route is the way I'll go.

At the most, I'll probably only be pulling 60watts through it, but most likely far less than that.

Thanks!

60W is only 0.5A. you wouldn't need a heatsink, and that would also make for a very small relay.

Well, Radio Shack was a no go. They had some automotive relays, but nothing in the voltage range that I need. Plus the guy working there didn't even know what a relay was.
I miss the days when Radio Shack employees were actually knowledgeable on more than consumer electronics!
I think my next best bet for electronics supply is 30 min away, so I'll leave this for another day.

Thanks again for you help!

http://cgi.ebay.com/Brand-New-Solid...ultDomain_0&hash=item2a03f7362b#ht_2901wt_913

$6.75 shipped is pretty cheap to me.

I was referring to the ones without the chinese writting on them.

I know this Is my set up but it works for what we're doing, I had thought of the difficulty of dealing with both low and high voltage and went with this..
I will look for a relay for you, but i bet its made in china

analog array with built in 10amp 110v SSR in ea
1 Johnson A350 controller for cold fan operation (it controls set point for all)
2 s350 controllers for heat and heater fan operation(they have offset points)
1 y350 24v power supply
same "mother of" design but I am using all 110volt, heater and fans

the freezer has a watlow pid controller and 1 110v fan for recirculation (fan on w/compressor)
the upper box uses the same fan for both cool recirc and heat recirc. with a diode between the 2 s350 controllers.
using a reptile heating pad for heat source and possibility a heat lamp in the dead cold of winter here(have another s350 for this if needed)
similar fans to mine
http://cgi.ebay.com/120-VOLT-COOLIN...510?pt=LH_DefaultDomain_0&hash=item53d9418d86

http://search.digikey.com/scripts/DkSearch/dksus.dll?vendor=0&keywords=pb106-nd

If you're controlling it with 12V, put a 50 Ohm, 1W resistor in series with the coil.

EDIT: or even better, this one is a 12V coil.

That would work! How would I go about mounting one of those in a neat manner though?

If you want it super neat, I'd put it on perfboard and wire it to screw terminals, then put the whole thing in a small plastic project enclosure (available from Digi-Key or Radio Shack).

Krazydave

I'm planning on building "The Beast" and am looking for control options. I have a similar problem being in Minnesota....the need for heat. I'm trying to figure out a love controller that will work the fridge compressor part as well as a possible heating chamber all in one. Build day is set for next weekend. I'll post pics.

Good Luck!!

Wow, never saw "The Beast" before. It's name is certainly fitting!
I'd definitely be interested in seeing the pics once you have them.
You could modify a thermostat in the same way that I did by extending the thermistor. Then as long as you have air circulation, use a reptile heating pad, or like I ordered, a ceramic reptile heater that fits into a standard light bulb socket.
With a couple relays rated for your power draw and some wiring, you should be able to set your thermostat to either heat or cool depending on what you need and it should work for you.
I've also seen some cheap $20 aquarium thermostats from eBay that people have used for that. You may want to search the forums for it to see what I mean.

I just finished my "mother" a few days ago and have been running some tests with it the past couple of days.
At first I put two 6.5quart storage boxes (plastic shoe storage boxes from Target) of ice in there and set the thermostat at 70. I filled a carboy full of tap water to simulate wort. To my surprise, not only did it cool the chamber down from 86 to 70 quick, but within 3 hours I checked it again and it was at 63!
I took all of the ice out and within an hour it stabilized at 68, which also happed to be the temp of the tap water in the carboy.

So... what that meant is that the temp of the carboy definitely played a huge role in the chamber temp.
Once the chamber temp rose to 70, along with the water temp, I put one ice box back in there and it's been stable at 70 for about 30 hours now, with about 1/4 of the ice left in the tray.
So far I'm happy with it, but come winter I'll definitely need to wire the heating element in there.

krazydave said:

Wow, never saw "The Beast" before. It's name is certainly fitting!
I'd definitely be interested in seeing the pics once you have them.

Click to expand...

So I have The Beast framed in and in its new home. Working on the caulking and getting the insulation for her. My Brother in law has some tin foil thickness R60 insulation that will line the inside along with some 2" foam board. Thinking of using the TSS2-2100 Dual Love Controller to control the temps along with a few computer fans for circulating.

Sorry some pics on their side.

Wow, that thing is insanely huge! Looking good so far!
I gotta ask though, do you think the height of the top chamber is a bit of an overkill? Looks like you could probably fit a 1/2bbl keg in there though!
Makes me wish I had a bigger garage, thats for sure!

On another note, my first two batches are in my "mother" chamber and holding steady at 68 degrees during high fermentation. I'm pleasantly surprised!
Eventually I'll have to see about finding a better way to cool it though as changing the ice every day pretty much rules out any weekend trips. And Brewing around trips is already proving to be a chore.

krazydave said:

Wow, that thing is insanely huge! Looking good so far!
I gotta ask though, do you think the height of the top chamber is a bit of an overkill? Looks like you could probably fit a 1/2bbl keg in there though!

Click to expand...

Yeah we had planned on the top housing the cornies but changed our mind. I have the option of putting in multiple layers of foam to close off some head room. It all depends on the configuration.

Eventually I'll have to see about finding a better way to cool it though as changing the ice every day pretty much rules out any weekend trips. And Brewing around trips is already proving to be a chore.

Click to expand...

Hey how about running a flexible line up here. We have plenty of cold air coming our way in the next month or two. I plan on tapping into the ambient outside air to cool when needed during the winter. Have to figure out how to control all that though.

HopHead24 said:

Hey how about running a flexible line up here. We have plenty of cold air coming our way in the next month or two. I plan on tapping into the ambient outside air to cool when needed during the winter. Have to figure out how to control all that though.

Click to expand...

I wish I could! I'd put on in my bedroom also!
It's supposed to be in the low 100's here for the next 4-5 days. Certainly a test for my chamber, that's for sure!

Pulling outside air for you should be a cinch... just get one of those house dryer vents with the little one way air flap in it and hook up a fan. Or I believe they may even have ducts with a flap like that for exhaust fans.
Just wire the fan to your thermostat like you normally would, but make it so it sucks air from outside through the vent.
You may also want a second vent at the furthest point also for full circulation, but it may work just fine without that. The air will most likely find a place to escape anyway.

krazydave said:

Well, Radio Shack was a no go. They had some automotive relays, but nothing in the voltage range that I need. Plus the guy working there didn't even know what a relay was.
I miss the days when Radio Shack employees were actually knowledgeable on more than consumer electronics!
I think my next best bet for electronics supply is 30 min away, so I'll leave this for another day.

Thanks again for you help!

Click to expand...

I always make the drive down to Orvac in fullerton. The guys that work there are extremely knowledgeable. Just tell them what you want to do and they will set you up with the parts you need and draw a diagram so you can build it. It's only a block or two from Addison's homebrew provisions so you can get your brew supplies all in the same trip.

It's been a slow go but I got my "Beast" wired and had quick test run. I hadn't connected the probes and got the alarms blasting at me. Wired them back up and the fridge kicked on!!!! So far I have a layer of R65 paper that looks like tin foil, a layer of pink foam insulation and another layer of the R65 stuff. Gotta get more foam and install the circulating fans and doors. The doors are gonna be a pain I think. I'll upload pics later.