outside air - pipe size and type?

[bag of hammers]

on my to-do list is an outside air feed for my stove (Osburn 1800). The mfg says to use a 5" pipe for this. In my setup I have to go about 15' horizontal thru the crawlspace to get to where I can push thru a rim joist (stove is centrally located so straight out the "back wall" is not an option). The mfg says I can block off the air intake on the back of the pedestal and feed air up underneath thru the floor if I want. The kit they sell is the adapter for the stove and the outside air vent, with a couple gear clamps, all sized for 5".

So I picked up 5" galvanized duct pipe, elbow, etc. - marked where I can cut the floor - but haven't started the job yet. It's pretty straightforward but looking at it now I have a couple of questions:

Is a 5" air pipe a bit overkill or pretty typical for outside air?

Is standard metal ductwork the best option? My crawl is enclosed and insulated on the walls so it's much warmer than outside in the winter - I'm worried about condensation on the pipe when as it's moving cold winter air thru that space to the stove. Maybe I should have just run PVC or something like that? Or maybe I have to insulate the pipe (hence the preference to use a smaller pipe if I can - it's just a bit easier to manage).

Any thoughts appreciated

Thanks

 

[fossil]

4" or even 3" would probably be just fine. Lots of folks just use flexible dryer vent for OAK piping, real easy to work with. It could be wrapped with insulation if you wanted to do that. Can prob'ly find adapters to fit it to the fittings in the stove kit. Rick

 

[bag of hammers]

thanks Rick - that does seem a lot easier - not sure why they recommend such a large size pipe. Appreciate the feedback