I just read about something that had never occurred to me - not heating your sparge water. Denny Conn waded into a thread on homebrewtalk.com and blew my mind. Others chimed in and a couple of folks confirmed that was their practice.
I have deep respect for Denny - he wrote the most concise and clear approach for the new brewer who wants to batch sparge. When I was transitioning from extract to all-grain, before I knew anyone else who brewed, I read a bunch, got really confused, then read Denny's primer. The heavens parted and I knew what to do. You can read his batch sparging primer here. Since then, I've gotten to visit with Denny a few times and judged with him at a competition in St. Louis last autumn. Like I said, I respect him tremendously.
In any case, here is the thread on homebrewtalk about it. I don't know if I'm going to try this or not, but with our super-dooper double water heater, using water straight from it is certainly an option. pH isn't as much an issue with batch sparging as it is with fly sparging, so that's not an issue. Increases your time to reach a boil, perhaps, and *might* decrease efficiency, although it shouldn't if you've got full conversion.
I suppose a bunch of you are going to say "of course, I do that all the time" but for me, it was new info.
Old dog, new tricks.