Son of Fermentation Chiller

So I am going to build a fermentation chiller this week/weekend. The box seems pretty easy & straightforward. My question is about the thermostat. I am going to use an electric thermostat and take the thermistor out, attach it to a longer wire so I can apply it to the side of the fermenter. It seems like a lot of these builds are measuring the ambient temperature in the inside of the box. I want to tape the thermistor to the outside of my bucket to get the temp of the wort, as I know it is usually hotter than the ambient temp. Any thoughts or recommendations? I will be brewing my third batch this weekend, so I am still a noob. Just getting tired of the ice bottle waterbath in the cooler (plus it has huge temp swings).

I am going to build one this week also but I am going to allow the thermostat to measure the ambient air temperature. I will have a fermometer on the outside of the bucket/carboy and I will adjust the thermostat to get that in the correct fermentation range. It just seems a lot easier to me.

You have huge temp swings with a water bath and ice bottles? Mine is pretty stable. I think you just need practice with it.

FWIW, taping the probe to the side of the fermenter should be fine; you might want to stick a kitchen sponge on there to sort of isolate the exposed side of the probe from the ambient air.

I wouldn't try to measure the fermenter's temperature. Since it holds so much heat, from 72 degrees, you'd have the ambient down to 48 long before the fermenter reached 68. Then as the fermenter stayed cool, the ambient would climb way back up over 68 until the fermenter caught up, then you'd have to drive the ambient way back down. With those wild swings, you'd be horridly energy inefficient. You'd be far better off monitoring the ambient air and using a fermometer. If the ambient is 68 and your fermenter is 72 and you want to be at 68, just drop the ambient to ~64.

I'm thinking about building one as well? Can you link to the plans your using?

This is the one I am going to build this week.

http://home.roadrunner.com/~brewbeer/chiller/chiller.PDF

Just built the mother of fermentation chiller this past week. Posted a thread on it somewhere in the DIY section if interested. I actually have a thermometer with a temperature probe taped inside the box. Since I have the stick-on thermometer on the outside of my fermenter I think it'll be fairly straight forward to square the temp away inside the box.

Use an indoor outdoor thermometer taped to the frementer to monitor the. brew temp. and adjust the thermostat.

I use this one and tape it to the side of the bucket with some foam over the top to get just the temp of the bucket.

http://http://www.amazon.com/gp/product/B001H1LTME/ref=pd_lpo_k2_dp_sr_2?pf_rd_p=486539851&pf_rd_s=lpo-top-stripe-1&pf_rd_t=201&pf_rd_i=B001F0RBI8&pf_rd_m=ATVPDKIKX0DER&pf_rd_r=0Y8546QATMVAJ69QEKXR

I am using these plans as well.

http://home.roadrunner.com/~brewbeer/chiller/chiller.PDF

I think I will take the advice and measure the ambient temp inside the chiller. Off to HD to get the rest of the materials for the build.

Built the box last night. That polystyrene is not the easiest material in the world to cut. Ended up scoring it on both sides with a utility knife and got a pretty good break. It is all glued together, should be able to finish up installation this weekend and then get some cherry wheat in it. Kegging my Chico Ale this weekend as well.

Good deal, mine was a pretty complicated build since I used plywood as my base, lined it with the polystyrene and then sheeted it with Red Oak. Has a Cream Ale inside it right now and is holding it at 66 degrees. Pretty happy so far *knock on wood*