What are these ducts?

Terminated in the attic, but there was no HVAC in the attic. Furnace was in the crawlspace with plenty of combustion air. The dampers were inoperable, both stuck in the closed position. I didn’t find the other end of the ducts.

They look like whole-house fans. The dampers stay closed unless-until activated. They will often include louvers to help prevent attic air from entering the house. If you didn’t see them in the ceiling, they haven’t been installed yet.

Does the yellow wire go to a damper motor on the side of the duct that looks like a bucket??? strange looking duct

I didn’t see any motor or any louvers. The home was built in '74.

black back draft damper connects in line with other component(s)
white plastic duct probably non-compliant for any usage
btw, none are correctly installed

Polly on to something there Bro Did I ever tell ya writing reports suck I am having computer problems with the connection between my chair and the key board:roll:

The positioning of the damper appears to be intake
and not exhaust
Was there an air to air exchanger in place?
a Hot Tub Room? Sauna?

No air to air exchanger in place.
The white flex duct was not connected to anything, it’s just debris.

I couldn’t tell what these things were connected to, but I’m thinking that maybe they’re from an old system that has been removed. Maybe the other end was hidden by the floor insulation in the crawlspace where the furnace is located. New furnace.