That got me thinkin. Why not?
Initially I was going to drill holes in the lid, but I opted to skip that step and use foil to cover it up. Much less of an expensive modification this way.
I've used it twice now. Run #1: Pump controlled by temp with sous vide circulating at 170F. So if the temperature drops below the set point (~152F was the set point here) it would start circulating until it got back up to temp.
This was fine, but I lost out on a lot of the efficiency I gained by constantly recirculating. Not a huge problem, but also not ideal. Worked great, but I wasn't satisfied.
Run #2: Constant pumping, sous vide set 2F above set point (same 152F set point).
It wasn't particularly cold on attempt one or two, so heat loss in the tubing was minimal and the runs aren't particularly long anyway. Run #2 was far more successful, though I did eventually bump the sous vide to 5F above set point which resulted in a fairly consistent 152-153F reading. I imagine I'll have to work on it over a few more batches to get it exactly the way I want it, and that's fine. But it's way more consistent this way.
I also got back to my normal efficiency numbers, which was really nice. Makes life easier when you know what to expect, and though the first test worked fine, it added another variable in pump run time that just... wasn't what I wanted.
For good measure, here is the IPA I made on run #2:
Carafoam - 8oz
Citra, Galaxy, Mosaic @ 9, 7, 5, 2oz each addition for about 65IBU.
GY054 (Vermont IPA Gigayeast) fermented for 10 days @ 66F ramped to 72F for 4 days. Cold crashed and kegged. No fining. Gloriously hazy, hop juicy as hell and I love it. Simple is better.