Nice set up

For two furnaces located within a basement one feeding the first level and one feeding the second story both units with a common return air duct leaving the basement. Never seen a residental unit set up this way just commercial.

Then in the last pic from in the attic they were trying to kill themselves CO from both furnaces and the WH discharging into the attic

nice find red hat…

I have seen tons of HVAC set-up from commercial and residential but I know and see that it is a great set-up.