I was wondering when putting in a 92+ furnace in place of a 80% furnace should I use PVC for the vent pipe? The old furnace has hard pipe for the vent. Why use PVC? I would like it if someone would explain this to me.
Thanks, Brian Coggin
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I was wondering when putting in a 92+ furnace in place of a 80% furnace should I use PVC for the vent pipe? The old furnace has hard pipe for the vent. Why use PVC? I would like it if someone would explain this to me.
Thanks, Brian Coggin
The flue gases on a condensing furnace are well below 212F, usually around 100 degrees. You will have water running out the joints in the flue pipe and the acidic vapor chewing up metal vent pipe in no time. That's why it has to be PVC. On the 80s and lower, the flue gases are 300-500 degrees and much less moist so they can properly vent in metal. Now, there are many 80% jobs vented in single wall pipe that shouldn't be...any garage for example should be double wall by code and many other installations as well.
Thanks for the info.
I'm trying to be carefull with my answer, no offence intended.
In a previous post you mentioned you are new to the site but have been doing HVAC for 2 1/2 years. Welcome to the board.
Now I'm having a little difficulty with understnding how one in his 3rd heating season doesnt know the difference between 80 and 90% furnaces yet wants to take on the job of installing one.
Where are you buying the furnace?
You do have an installation manual and are using it for more than a knee pad, right?
Havn't got the unit yet buddies so I havn't read the installation manual. Live in the south. Don't ever put in Gas furnaces either. This one farther up north. Im use to Heat Pumps. I change a gas furnace its usually to a Heat Pump.
You do have some one with gas expereince helping you.
Someone to set it up, right?
I know how to hook a gas furnace up. I've worked on a many of one. Just never put in a 90% furnace. Not a big demand for them where im from. I have no problem installing it. Only question I had was about the flue pipe. And one of you kind fellows answered that for me. Thanks.
Hooking up and setting up are two completely different animals. Good luck
Where in the south u from ???
Doc, we're old and bald, we never never had that atittude,LOL...Quote:
Originally posted by docholiday
Hooking up and setting up are two completely different animals. Good luck
Coggin, so what meter do you use for combustion set up on the gas furnaces you installed.
Used a Kane 250.
Ok, now don't the instructions for your meter tell you to drill a hole in the pvc pipe for 90+ furnaces.
LOL...
Just jerkin your chain, thats a nice tester.