Running Wires in Conduit inside a wall
Here is the situation.
I am in the middle of remodeling a bathroom on the upper floor of a split-foyer. It is right above the unfinished laundry, where the electric box is situated (the lower level is the basement and above the first floor is an unfinished attic). I have taken everything off down to the framing. In the corner of the bathroom there is a roughly 3x4 enclosed passageway that runs straight from the laundry to the attic. In it, the builders ran the main A/C air duct to upper floor, as well as the flue from the Gas Water heater and Furnace. This chase is enclosed by framing all around and has metal sheeting on the top (to attic) and bottom (to basement).
I had this idea about running 2 conduits from Basement to attic to “future-proof” the place and get ready for future remodel ideas! Conceptually, I would use one to fish electric wires (I was thinking of the usual 14/2 NM-B and 12-2 Romex NM/B which have been ran elsewhere) and the other to run low-voltage wires (RG-6 and Cat 5e. perhaps speaker wire). The purpose of the conduits would have been to simply have a path (it will be about a 9 foot run) between the attic and the basement) to simplify future wiring.
As I look into this, there seems to be more to it than the electrician at the local home improvement store conveyed. I am hoping readers here have better ideas:
1. What other approach would you use (if not what I am trying to do) to accomplish the same purpose? (note: the rest of the house if finished and I won't get the same straight shot to laundry on any future project)
2. If going the conduit route, I was recommended to use 2 x 1inch PVC 10 foot conduits.
a. Would the scenario be OK for low-voltage wires;
b. I have come across things like fill % (seems to be 40% for 1” pvc pipe) for NM wire in conduit. Apparently, there is danger of overheating. But this would barely give me 2 runs and defeat the purpose of what I had in mind! Ideas?
c. If I run a conduit, what could I do at the two ends for:
i. Fire protection;
ii. Prevent Insects from crawling it;
iii. Preventing heat loss from basement to attic