What size vent for reznor

[boostaholic1]

Ok fellow GJ members,

Needing professional help (not the couch kind). I am running the vent for my 170k btu reznor. I'm pretty sure it calls for 8" b vent as it is a natural type vent. It has proven to be difficult to find double wall 8", however I did locate some at a reasonable price, but it is 2 weeks out.

Which leads me to my question. If it calls for 8" natural vent, could I get by with starting with 8", putting a fan vent in and then reducing it to 6" the remaining 8 or 9 foot?

It is much easier to find 6" opposed to the 8". Thank you for all help.

 

[brewchief]

No you can't make a reduction like that, there are times when you can reduce one size but that would only be from 8" to 7".

You can't simply add a fan, there are power sidewall vent systems and inline vent systems that can be used but you could probably buy a power vented heater for the same price.

Simply running 8" b vent straight up through the roof is going to be the best way, you can use single wall pipe for the vent connector from the heater to the vertical vent in most cases as long as you can maintain proper clearances.

Sent from my SM-G965U using Tapatalk

 

[seanc_mt]

My Renzor 225k btu in new warehouse has 8" straight through the roof. Works good.

 

[Trapps]

We have UDAP 100s and 150s in a warehouse. The 100s use 4" B-Vent, the 150s use 5".

Go to page 6 in this document for specs:

https://www.alpinehomeair.com/related/Reznor Installation Instructions UDAS - UDAP.pdf

I'm not familiar with the 170 sized unit though.

 

[fitter30]

What size is on the furnace if its a oval measure the circumstance and compare that to round pipe 8"- 2 5.12, 7" - 22" , 6" -1 8.84"