I currently use the system that Nathan sells, which is the 10G BIAC and the Lindr chiller. Got to say that the setup is pretty awesome except that mash temperature control is somewhat inconsistent in that actual mash temperatures varies significantly throughout the mash even though the temperature controller says it is at a specific temperature, ie. 152F. I have a 2 foot long temperature probe sold by Thermoworks where I can measure the temperature at all depths in the mash. The temperature can be 154F at the surface, 147F at the base of the mash-tun, and all temps in between. With 18 gallons of water, 32 pounds of grain, and 2 pounds of rice hulls, getting a consistent 152F throughout the mash-tun is difficult. Just because the temperature controller says 152F and the recirculation looks good, doesnt mean that the entire mash is at 152F. The variation in the mash temps have not effected the amazing quality of beer I can make with this system.
What I have been doing is mashing in with 168F water with the 34 pounds of grain and hulls, and keeping the temperature controller at about 157F to get a grain temperature near 152 (BTW, 18 gallons of water and 34 pounds of grain maxes out the 10G BIAC). I stir the mash about 4 times during the hour. After an hour, I start raising the temperature by a few degrees every 5 minutes or so until I get to 174F on the controller. The grain temperature never gets past about 167F all the while I am raising the controller temperature. I have done thirteen 10 gallon batches now in my BIAC and the results are consistent.
Temperature control with the chiller and during fermentation is excellent, within 1 degree. I normally chill the wort with Chicago city water to near fermentation temps, then hook it up to the chiller. Precise fermentation control is achieved by using the chiller, and using the heating probe set to 3% power setting. I only use one or the other, but because my basement is near 66F, I have to switch to the heating element near the end of fermentation to raise the temps to 67F and above to finish off.
When fermentation is done (I usually wait for 2 weeks), I set the temperature controller to chill the wort to 37F. After a day or two, I generally fine with gelatin and leave it for 2 more days at 37F (this is the lowest setting I can achieve with the water chiller). Then rack the clear beer to 2 corny kegs.
I recently had a problem with the chiller that confused me. My chiller sat on the floor and for the first 11 batches the system worked as advertised. Then I started getting back-flow from the jacket into the chiller through the input hose when the temperature controller shut off the chiller. The result was 2 gallons of water into the overflow bucket, then icing of the coils in the chiller the next time the chiller was turned on. The fix (Nathans advice) was to elevate the chiller to be at or slightly above the jacket so the back-flow does not happen. That fixed the problem.
Have any of you experienced the same things I have???