Added water for dead spaces?

[BrewHogDeluxe]

I was wondering???
I have a 3 Keggle set up planning on running a one pump set up and I was wondering how much "extra" water I needed to add to account for the dead spaces? Meaning the wort that is left in my mas tun heating coil 25', the bottom of my mash tun, the bottom of my boil kettle, my various lines etc.

 

[Yooper]

I was wondering???
I have a 3 Keggle set up planning on running a one pump set up and I was wondering how much "extra" water I needed to add to account for the dead spaces? Meaning the wort that is left in my mas tun heating coil 25', the bottom of my mash tun, the bottom of my boil kettle, my various lines etc.

Well, the amount in a HERMS coil is pretty insignificant, but if you don't like leaving wort in there you could always flush with water through the pumps and the HEX at the end, to get out all of the wort. I have a HEX in the HLT, two pumps with some lines, and a CFC, so at the end I just switch over to water from the HLT to flush out all the wort into the fermenter.

I tend to mash with 1.5 quarts of water per pound of grain, and don't use extra for dead spaces under my false bottom and it still gives a thin enough mash to work with and pump.