[Gar1]

I have a 30L AIO, and I've made twenty brews with it, maybe more. I make mini sparges with 5-6 liters of water, sometimes even at room temperature; it doesn't seem to make much of a difference. Efficiency is always around 70%. I stir every 15 minutes during the mash and chop the grains 2-3 times during the mini sparge. I generally make 18-25 liter brews with medium OGs.Beautifulideas.in
What makes a big difference is the pH control (I use stabilizer and very rarely need to adjust with a little lemon), not the temperature of the sparge water. I'm a bit of a slouch; I use litmus paper because it's as good as a Chinese pH meter, if not more (I worked in a research lab for a few years and remember the problems calibrating a "serious" pH meter or measuring a "real" temperature to the nearest tenth of a degree...).
Hi
Mario.

@Mario61, regarding room temperature sparge: I've always read that the water should be warm (~78°C) to make the wort more fluid and facilitate sugar extraction. Using cold/room temperature water, have you ever noticed filtration problems (such as "stuck mash") or differences in the final flavor compared to traditional sparge?