On Nov 28, 4:15*am, "spud42" wrote:
wrote in ...

On Nov 25, 1:07 pm, "spud42" wrote:





wrote in ...
I never said it was. And venting it out a side wall is the
most used option. But I was responding to those who implied
that the existing chimney is a viable alternative for routing the
PVC pipes. From all that I see and know, it's typically not an
option at all.....

There is significant variation between manufacturers and even models
But 3 elbows and Something like 65' or so. 8 elbows may only get you down to 40" not 35
The install manuals I've read cover using existing unused chimney as a option

As far as supports I don't know but typically support requirements for
almost everything are very relaxed when running say through a small chase.
Go take a look at the install manual for a typical gas furnace.
It's very specific, requires the PVC pipes to be supported every
4 ft. No exceptions for a 30 ft run up a chimney. Have you ever
seen a PVC pipe run of any kind the length
of an entire chimney that isn't supported every few feet along
it's run? One that passed a plumbing inspection that is?

it very well specific as in Horizontal runs of vent/flue piping must be supported
also
"The vent can also be run through an existing unused chimney; however,
it must extend a minimum of 12 inches above the top of the
chimney. The space between the vent pipe and the chimney must
be closed with a weather-tight, corrosion-resistant flashing"
Not the best choice But yes it can be done but it's a lot trickier to get right

Link for where that came from?

http://www.goodmanmfg.com/Portals/0/...s/IO-GKS9.pdf- Hide quoted text -

- Show quoted text -

Thanks for the info. Goodman is a lot more lenient in their
reqts than Rheem. The Rheem manual I have limits vent pipe
runs to probably half of what Goodman allows. And there is
no mention by Rheem of using an existing unused chimney.
I still wonder what an inspector would say about such a long run of
unsupported PVC vertical pipe. I guess if you properly secure
it at the top and bottom, it would be OK. The biggest
road block is probably a remaining gas water heater that could
be venting through the same chimney. I guess you could
potentially replace that with a power vent type and if the run
is within limits and it will all fit, use the chimney to run that too.
There is also the issue that for the allowed run lengths, you'd
have to stay at or below 70,000 btu to use 2" PVC. Above
that you'd have to use 3" to make it to chimney length. And
getting two of those in there could be a challenge in some
cases.