Yes, it is more like a HERMS than a RIMS. Thank you. The main difference is that hot water is pumped through the coil not hot wort. Also, the coil is in the mash tun not the HLT.
I have been batch sparging for awhile now with 1 burner, 1 keggle, 2 coolers and no electronics. I would like to step mash (only 2 steps) and fly sparge without getting any additional equipment.
I just read an article in BYO Jan-Feb 2013 by Walter Diaz about pumping hot water through a copper...
Heres another version of an inline T. Sorry about the bad picture but you can see all the air being pulled in below the T. I think it helps to have an 8-10 foor drop into the basement.
I used 2x10's so I could fit a keg on the hump. I think a good seal on the top and bottom are more important than extra insulation. Insulation is always something you can add later when your DIY list gets shorter.