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Advice on Duct Vent

drock1212
drock1212 Member Posts: 3
edited July 15 in Chimneys & Flues

Looking for advice on Furnace Duct Replacement. Duct rusted out and existing connection strategy doesn't seem ideal to me. Considering a 10-7 or 10-8 reducer with high heat caulking or mastic at the flange connection and a 7 or 8 in dia stainless duct with rain cap.

Comments

  • mattmia2
    mattmia2 Member Posts: 10,817

    I am not the expert on these, but I think there is a listed transition that is part of that vent system that has to do the transition to plain stovepipe.

  • bburd
    bburd Member Posts: 1,023

    Bburd
  • Bob Harper
    Bob Harper Member Posts: 1,086

    Wow! What a goat rodeo! Whatever that mess is, I'd completely replace everything with a new listed system. Now, what is the equipment, BTU input rating, appliance collar, vent rise and lateral offset and same with any common vented appliances. You're lucky nobody died nor the place burned down. Scary. Pics inside of the equipment, rating plate data, and vent connection

    mattmia2GGross
  • drock1212
    drock1212 Member Posts: 3

    Hi - Thanks for the input. It certainly isn't a good setup right now.

    Furnace is Lennox SL280DF070V36A-05. BTU input is 66k/43k. Included more info in pictures below from garage.

  • mattmia2
    mattmia2 Member Posts: 10,817

    You need a competent professional. That rotted out because it isn't working right.

    GGross
  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 16,363

    You need to get rid of the 4 90 degree elbows on the furnace ven and connect that with a minimal offset. The double wall pipe needs to extend through the roof.

  • PRR
    PRR Member Posts: 226
  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 16,363

    @PRR offset the larger pipe above the filter with 2 45s and bring it down in line with the return duct

  • Bob Harper
    Bob Harper Member Posts: 1,086

    Keeps getting better. Switch to a CAT IV furnace so you can locate the intake and exhaust pipes clear of the filter and remove that abortion of a vent job. Still searching to find a single thing acceptable or correct.

    Foil tape is not a vent connector nor is it allowed on connectors

    Connectors must use shortest route possible to the common vent or chimney

    Must discharge into an approved vent or chimney

    Connector must rise 1/4" per LF w/ 3 screws per joint

    Must use listed connectors from single walled to B-vent

    Must maintain access 30" wide x 36" out x 6.5 ft tall

    Improper firestopping on disastrous factory chimney

    No fireblocking

    FSK tape within 6" of unlisted single walled vent connector

    Pull the chain and flush

  • pedmec
    pedmec Member Posts: 1,055

    that needs a whole redo from both appliances out. its worse than i thought. And im not even going to ask about combustion air because i dont expect an answer

  • drock1212
    drock1212 Member Posts: 3
    edited July 17

    Thanks for the advice. I knew the vent connection at the roof was not good but didn't realize the portion within the garage also had issues. Will look into having a professional fix the setup. Btw what is all the white dried stuff that looks like it's been dripping down?

    I don't know when the roof portion was done it maybe was completed before we bought our house in 2014 but was likely at least touched when we had our roof re-done in 2018. The vent portion "within the roof/attic area" is probably original to the house (60's build). The furnace and the venting on the inside within the garage is new though as of 2021.

    Is there any way we can still feasibly work with at least the existing furnace and just redo the venting? Is there any recourse or anything I can say to our HVAC installer (they are a major company in the area) about it to get it fixed properly? How do we ensure that work is done properly in the future - like do I need to hire an independent inspector when HVAC work is done?

  • mattmia2
    mattmia2 Member Posts: 10,817

    The white stuff is corrosion from condensation in the vent because it is not drawing right.