A remodel (in the Pacific NW) we are considering would entail:

- Removal of a chimney that wastes precious space in our tiny kitchen.

- Replacing our _horribly loud_ and _stupidly placed_ gas forced-air furnace (combustion air supply PVC pipe actually blocks part of a doorway!) with a high-efficiency one that would be upstairs and hidden behind the living space's knee-wall pretty decent height there -- an old electric water heater used to be there till I removed it.

If moved there, the furnace would still be directly adjacent to the chimney's location, just a floor up. Therefore ducting should be fairly easy:

- hot air supply & return could go through a coat closet we'd gain in moving the furnace upstairs.

- exhaust venting could still go through the chimney's roof penetration.

I don't know if this is a "downside" of that location, but I'll mention that we had the house insulated last year, so there is a lot of blown-in insulation in the potential furnace location. I'd guess it's not a problem per se, but just an inconvenience during installation and we'd better just make sure that the insulation gets replaced/redistributed as well as possible after furnace install.

Alternately, the furnace could be moved out to the utility room, as we are considering replacing the (possibly dying) gas water heater with a tankless one which would free up space. The utility room is a walled-in breezeway between the house and the formerly unattached garage, thus it is outside of the foundation and I am wondering about the difficulty of furnace ducting through it.

I know my description lack a lot of context for y'all, but any advice (location & type of furnace, anything) is appreciated. Thanks.