Need some HVAC guidance (furnace flue venting)

[kenmac]

change it back now like you wanted it to begin with and go with a 95% eff. furnace. If you don't, you may regret it the rest of the time you are in the home.
Terminate the 95% out side the wall, or go through the roof. Your choice

 

[Sigarms]

change it back now like you wanted it to begin with and go with a 95% eff. furnace. If you don't, you may regret it the rest of the time you are in the home.
Terminate the 95% out side the wall, or go through the roof. Your choice

+1

And ensure you go with a two stage gas valve.

 

[rbstern]

Follow up: HVAC company's field supervisor was here this morning looking at the install. They're going to correct it all. The furnaces can be installed in the mechanical room, as originally intended in the blueprints, and the flue routing to the existing, rear roof line stack is achievable with the existing units, without power venting. One extra elbow and a rising 12' horizontal run.

They're sending a company employed crew leader and crew out to handle the work, rather than the screw-ball sub-contract crew they used for the initial install.

A lot of waste in the way this was done, but it's gonna get corrected and we're not on the hook for any of it. I could tell the supervisor was frustrated with the way the farmed out work got handled. He was biting his tongue, but it was obvious he was frustrated; he was finding numerous examples where he had made notes for the install that they didn't follow.

 

[prof fate]

Maybe...
I had a furnace isntalled and he ran 2" pvc out the side wall...fine for 2 years then the furnace started short cycling and not producing heat. Called in a repair guy and YOU GOTTA READ THE MANUAL!

Yes, 2" works but the max run is 28'. the smaller print (or maybe what you should learn in school) is a 45 degree turn is equal to 4', a 90 is 8'. So the total run with the bends was 35 feet. Why it worked for 2 years isn't clean, but changing to 3" pipe fixed the issue.

Most effecient placement for ductwork would put the furnace in the center of the house.

What a screwed up contractor not to mention HE furnaces ahead of time. 2" PVC in and out the sidewall is the way to go. Try to get it changed back weven if you need to send the units back, if you can. HEs are more expensive though but have a neat installation/

 

[rbstern]

And the wrap up: The company-employed crew was here on Friday and today. They undid everything the original sub-contractor did. Removed all duct work, moved the furnaces to the proper location, and proceeded to neatly and professionally do a proper install, with the ducts neatly and efficiently routed.

A happy resolution.

 

[BrokeFarmerJohn]

And the wrap up: The company-employed crew was here on Friday and today. They undid everything the original sub-contractor did. Removed all duct work, moved the furnaces to the proper location, and proceeded to neatly and professionally do a proper install, with the ducts neatly and efficiently routed.

A happy resolution.

Good deal, I’m happy it all has worked out, what could have been a nightmare situation for years to come has been avoided by the sounds of it.

 

[rbstern]

Good deal, I’m happy it all has worked out, what could have been a nightmare situation for years to come has been avoided by the sounds of it.

Thanks. Me, too. Appreciate yours and everyones helpful feedback.