# PEX in Plenum Spaces



## Plumb488

Our company is bidding on a new school in Ohio. We have done many in the past 20 years but this is the first that the specifications are allowing PEX pipe for domestic water, 1" and smaller. I am wondering if anyone has had code issues with using PEX in a plenum space? I have contacted Nibco and they say theirs is not plenum rated. Does someone make plenum rated PEX?

Thanks for any info I can get on this!


----------



## nhmaster3015

No. And the mechanical code won't allow it either


----------



## Ghostmaker

Plumb488 said:


> Our company is bidding on a new school in Ohio. We have done many in the past 20 years but this is the first that the specifications are allowing PEX pipe for domestic water, 1" and smaller. I am wondering if anyone has had code issues with using PEX in a plenum space? I have contacted Nibco and they say theirs is not plenum rated. Does someone make plenum rated PEX?
> 
> Thanks for any info I can get on this!


Are the plans your using for a quote been approved by the state of Ohio or the local code authority yet?

In my area of Ohio all piping in the plenum for the schools had to be fire resistant materials. Inspected 3 elementary and 1 High school this past year. Plastic did not meet that requriement for schools. But maybe the code has changed regarding this matter. I would suggest you call the engineer and get a response in writing.

Schools have different requirements then other buildings for fire code etc..


----------



## deerslayer

http://www.uponor-usa.com/Header/Systems/Plumbing/Homeowner/EIR-Vote.aspx

Uponor is supposedly plenum rated and they are using it in Hospitals around Cincinnati, not that I agree but they are doing it


----------



## Gettinit

deerslayer said:


> http://www.uponor-usa.com/Header/Systems/Plumbing/Homeowner/EIR-Vote.aspx
> 
> Uponor is supposedly plenum rated and they are using it in Hospitals around Cincinnati, not that I agree but they are doing it


Nice grab. Nobody uses that type of pex pipe here. I had no clue.


----------



## Ghostmaker

Learned something new today CPVC is good in Plenums....


----------



## billwestrick

most school construction today does not allow return air plenums. they are banned in indiana.
vanguard canpex has a plenum rating up to and including one inch. BUT. it has to have an 18 spread between pipes to meet this rating.

its good pipe. we use SS side crimp bands. no issues. just buy new tools for every job.

bw


----------



## Hoozycoozy

billwestrick said:


> most school construction today does not allow return air plenums. they are banned in indiana.
> vanguard canpex has a plenum rating up to and including one inch. BUT. it has to have an 18 spread between pipes to meet this rating.
> 
> its good pipe. we use SS side crimp bands. no issues. just buy new tools for every job.
> 
> bw


You buy new crimp tools every job? Seems wasteful.


----------



## grandpa

On the Uponor website, I see that it is return air plenum rated IF covered with 1/2" fibreglass insulation.


----------



## Plumb488

Thanks for all the posts. Since my original post I have learned they are changing the spec on the project and are only going to allow it in the walls, not the ceilings. I did learn quite a bit though. Many of the PEX piping systems require insulation to meet the flame/smoke ratings. Also, the project called for heat trace temperature maintenance system and that presented a problem due the the thermal conductivity of the PEX being so low. The inspector for that area said no way! Truthfully I would prefer to just stick with copper. I guess I am pretty old school. Thanks for everyone putting in their experiences. I'm old to the trade but new to the site so it's nice to know you can go somewhere to get other opinions.

Plumb488


----------



## 6th Density

Yea, I've ran across the issue before... to use plastic or metal pipe. Like you just said, it all comes down to the insulation. Plenum wrap insulation is not cheap (if I remember correctly around 5.00 to 8.00 dollars per foot). But if it means that you can haul 8" to 10"PVC pipe (instead of cast iron) 30 feet up into ceiling (job for a movie theater) for roof's storm drainage system, sometimes the plenum wrap has its advantages.


----------

