Help with fermentation chamber build

[oldbullgoose]

I picked up large chest freezer off Craigslist for $75 bucks. I was looking for an upright about the size that it is so that I don't have to lift the 1/2 barrel sankes that I use to ferment in and out of the freezer. The price was too good to be true though and I went for it. Eventually I'll rig up something like an engine lift to help me lift in and out, but for now my brew team and my strong back will have to do.

It works like a charm and I've currently got it rigged up to a Ranco dual stage temperature controller and set at 35 degrees. The thing is ancient, American built, and insulated like a tank, so it rarely turns on. Right now I've just got some beers conditioning in it and two beers serving via picnic tap:

What I'd like to do with this is turn it into a fermentation/conditioning vessel with an ambient temperature of right around 40 degrees and the capability to individually control 2 fermenting sankes at lagering temps (~55) or lower-mid range ales (up to 65). My basement stays around 68 in the summer, so I don't have to go up above that.

My idea was to pick up a few feet of reptile tape to wrap around the sankes, build some sort of insulation jacket perhaps out of HVAC duct wrap, rig up individual cheap temperature controllers for each fermenter, and have thermowells for each fermenter.

I have a few questions that I'm hoping you all can help me with.

1) Is there a more efficient way of doing this in the freezer?

2) Will the heat mess with the freezer? I'm hoping the insulation will insulate the heating element on each fermenter so that it doesn't radiate heat and affect the cooling of the chamber. Anyone have experience otherwise?

3) Will this be a huge power suck? If the freezer is at 40 degrees, will the heating elements be on constantly and spike my energy bill?

4) Is this a huge fire trap?

Thanks. I'm looking forward to getting temperature control down. Over the winter I lagered with a 25 year old heating blanket wrapped around a keg in my stairwell. Talk about fire trap...

 

[mmeadows24]

To answer your questions:
1) Yes, there are many other more efficient ways to do this but it comes down to cost benefit analysis. If you aren't looking to spend a ton there is always the light bulb paint can DIY. Although personally I think that is a less than ideal setup. I bought 9 ft. of heat tape from Reptile Basics Inc. ( http://www.reptilebasics.com/heat-tape ) with their clip set and it was about $56 with shipping. I had them cut and wire it for me in 27 in lengths giving me 4 heat wraps (essential the same as Fermwrap). I think that is a great price for the setup. The benefit with this is I can ferment at least 4 different batches at different temperatures ( I have a 3 in 1 stc-1000 control panel plus a single one).

2.) No, I don't think the heat will mess with you freezer. Although, truthfully I can't speak from experience as I have never used a heating blanket in this sort of application. While modern heating blankets have several safety measures I personally have found them fickle in their use they were designed for, so placing them in an environment with shifting temperatures and moisture (in the form of humidity) I wouldn't do it. That said there are many people on here who have used them successfully so take my input merely as an opinion.

3.) Your power consumption will be depended on the efficiency of your freezer (they use a bit) and the wattage used by the blanket. It would very difficult to give you hard numbers but it should be ok and depending on where you live and the weather the cost will be manageable. Your dual controller should not run your freezer at 40 F and run the blanket full time. It is designed as a relay that will cut power from one socket as it powers the other. So at any given time one one will be running.

4.) Dunno. The blanket should have safety features. Many guys have done this and never had a problem. My feeling is that blanket (not the heated one) is a torch waiting to happen. If the heated blanket is damaged and if you get a spark it could be bad news. A lot of if's there but there are setups out their that are similar in cost and have less risk involved. To each his own but I would rather go safer than the easy/cheap route.

Good luck and hope my opinions are helpful.

 

[mmeadows24]

Btw, your potential setup you have said you would like to do is EXACTLY what I use. My only thing is I ferment in corny kegs. They are lighter, easier to move around, no need to cover from light, and have muti-application in brewing. I have never owned nor will own a glass fermenter and I am WAY to anal to use plastic because in my mind it's limited life and larger footprint out-weight its benefit. I have a completely closed system so there is virtually no air introduced (even when transferring) as I push from keg to keg with nitrogen/cO2. The heat wraps use about 50 watts but at far more efficient than just about any other heat setup out there in the price range (unless you are blessed and live where you have an average temperature that stays in ideal fermentation temps year round).

 

[freelunch]

I don't have an illustration available, so I will try to use words to paint a quick picture of my recent thoughts on this matter.

As you mentioned, you need insulation to keep colder air away when trying to hit two different fermentation temps in a single freezer. 10F or more of difference is where it gets challenging.

My scenario: ferment a lager and an ale at the same time.
My plan: build a cube using foam board insulation material to separate the ale fermenter from the walls with cooler lines, an the cold air.
Set the freezer temp controller for lager fermentation temps, and attach to lager fermenter (insulate well).
Install a second temp controller for the ale fermenter with cold relay attached to a blower fan to pull in cold air from freezer, and hot relay to power a heating element in direct contact with fermenter.

Hope that made sense.

One more thought - think outside the box. Since my freezer also hosts 5 taps for serving beer, I don't always have room for fermenters. I am considering building an insulated cube next to the freezer, and creating an air duct (x2) out the side of the freezer collar, and into the insulated cube to allow a controller to circulate cold air from the freezer as needed.

Let me know if you want more details, or if a drawing would help. I am still a week or two away from modifying my set up, so I don't have pictures yet.

 

[freelunch]

If you like the 'outside the box' concept, it looks like a new discussion on the topic just popped up in another DIY thread.
https://www.homebrewtalk.com/f51/keezer-powered-external-fermentation-chamber-403530/

 

[oldbullgoose]

Thanks everyone for the help. I've got the reptile tape and reflectix tape on two sankes in my freezer and the controllers holding it at 55. The ambient temp is 38 and they seem to be holding up. Success!

It looks like I will have to get 1-2 more of the reptile tape for extra sankes to do fermentation for ales in my basement. I can't be happier with how they perform though.