Another view of the top. Notice that the coils are flattened to maximize heat conduction:
Here's the label on the unit:
Here's the newly-replaced drain system for the house (the old layout was a mess). 2 showers feed into this: one on the main floor (through a 2" wye that's on the backside), and one from the 2nd floor (which dumps into the 4" stack higher up):
And here it is once the DWHR unit has been installed. A ProFlex at the top, and a Fernco at the bottom (both supplied with unit). In hindsight, I should've ordered the next size up of DWHR (R4-48") and used a ProFlex both top and bottom -- it would've given me 10% better heat recovery (saved an additional $35/year).
Tomorrow we will finish up by connecting the supplies and wrapping it in insulation.
I have no affiliation with these guys. Just saw DWHR units mentioned in my Home Energy Audit (which outlines how much grant money is available for various house upgrades) and started doing my research.
I have yet to meet anyone in town yet (plumbers, inspectors, home energy assessors) who have ever seen one.
Once it's up and running (tomorrow), I'll re-measure the temperatures and post them here.