Click here to Find a Contractor in your area.
Welcome! Here are the website rules, as well as some tips for using this forum.

If you've found help here, check back in to let us know how everything worked out.
It's a great way to thank those who helped you.
Need to contact us? Visit

Who still is doing duct work ?

As time goes by I see less and less real duct jobs and see more and more flex w distribution box set up .this does not seem limited to the trunk slammers as I ve recently seen a few larger older companies doing there jobs this way . I realize that it s faster and cheaper is utmost aside from profit and seems to be the new way,am I wrong to think it a little amateur and hacky or am I just set in my ways and old fashision becoming a old timer and just can’t see the quality in that style of layout .Or could it be that it’s the slop that people want at the price there willing to pay I mean what do they know expect price and what ever the contractor tells them and of course it’s all bubble wrap who wants to work w fiberglass wrap the help hates it .lol peace and good luck clammy
R.A. Calmbacher L.L.C. HVAC
NJ Master HVAC Lic.
Mahwah, NJ
Specializing in steam and hydronic heating


  • ratioratio Member Posts: 2,447
    Sounds like you're one of those Old Guys, who likes to do it the best way & not the cheapest way.
  • HVACNUTHVACNUT Member Posts: 3,371
    Spider system. A short supply plenum and flex everywhere.
    Its definitely a hack job. Cheap and quick. The main trunk needs to reduce due to the loss of static pressure from the upstream branch ducts. Expelling CFM accordingly.
    It's been going on for years. Low bids on condo's and tract homes. Now I hear arguments that with an ECM motor it doesn't matter. Really? When 1600 CFM gets pulled in, 1600 CFM wants to get out. All that turbulence in a short plenum makes for an extremely unbalanced and very loud system.
  • clammyclammy Member Posts: 2,501
    Yeah I m not that old but always take a hint from old timer tin knockers always loved the old branch duct systems with duct transition after each take . Some where extremely thought out ,the craftsmanship displayed on the install is a far cry from what I see of a new .i believe the extended plenum is quite popular these days w a lot of flex , that aside from the distribution box system w possibly some larger diameter flex aside from all the other flex . Funny how as time goes by what hides in attics and drop ceiling are a far cry what was once . Peace and good luck clammy
    R.A. Calmbacher L.L.C. HVAC
    NJ Master HVAC Lic.
    Mahwah, NJ
    Specializing in steam and hydronic heating
  • Jean-David BeyerJean-David Beyer Member Posts: 2,663
    I do not know who does duct work now, but I know who used to do it around here. They fabricated all the ductwork, and the inside of the ducts were lined with about 1/2 inch black foam rubber. I do not know what it really was, but its main purpose was to reduce the heat loss through the ducts (that ran through a crawl space).

    But there must be a lot of completed duct work out there because I get several robocalls a week warning me to hire them to clean my duct work before my house burns down. They are pretty ignorant. What duct work? My house is heated with hot water. I have no AC, so the only duct is the one from my clothes dryer to the outside.
  • clammyclammy Member Posts: 2,501
    Yuk lined duct my old boss had a saying when ever we encountered anD It was ,you use that stuff in people who u don’t like homes .lol never seen rubber based usually it’s a fiberglass product w not much r valve usually us3d to quite as a sound dampener as for real insulation for duct work it’s usually ensuffecent in attic jobs .i m old school foil faced fiber glass stapled taped w reenforced scrim tape then bailing wire and of course all joints mastic taped and sealed ,I seal the snap lock seam if it’s pre fab always loose .the only time I get lined stuff is for duct drop through curbs but we usually have a roofer insulate the outside of the curb and add cantors before they seal it up no Karnak curb fills here ,old school is the only real way on some things espically curbs .i laugh every time I see the adapter curb on adapter curb then you need a ladder to service a small package unit crazy Peace and good luck clammy
    R.A. Calmbacher L.L.C. HVAC
    NJ Master HVAC Lic.
    Mahwah, NJ
    Specializing in steam and hydronic heating
  • Mike_SheppardMike_Sheppard Member Posts: 657
    I’d imagine more people would do ductwork if the customers weren’t selecting the lowest bids.
    Never stop learning.
  • STEVEusaPASTEVEusaPA Member Posts: 4,143
    My brother is still doing it the old fashion (good/right) way.
  • HVACNUTHVACNUT Member Posts: 3,371
    Down south and I'm sure in other places, they use duct board so that doesn't count. Except for the end user who gets to breathe fiberglass directly. Insulating ductwork taught me how to wrap presents like a pro.
  • mikeg2015mikeg2015 Member Posts: 1,178
    We have a lot of old home with unuseable, damp stone foundation basements plus crawl spaces. In this case, flex tends to work a lot better, quicker ot install. You just need to size it right, which means going up at least one diameter in most cases. I have flex on my own house, but it’s a 2 ton system with 5 8” supplies with oversized 6x14” grills. It’s dead silent and low static. Flex is very quiet when sized right.

    Of our installs, we do a mix. Most commonly we use a metal truck then flex runs to the registers and size it using duct calculators.
  • Steve MinnichSteve Minnich Member Posts: 2,540
    Up until 8-9 months ago, I still had all the sheet metal fabricating equipment needed to make anything. If you could dream it, I could make it. #tinman
    PHC News Columnist
    Minnich Hydronic Consulting & Design, LLC
    Jean-David Beyer
  • unclejohnunclejohn Member Posts: 1,554
    Still use sheet metal in the few jobs I do. Luck enough to have a guy that can make it if you can draw it. If steam heating is a lost art sheet metal will also soon be. I have seen supply plenums that are one piece and have 8 take offs. Mostly I'm working on whats best, part C, G, F, or N.
  • tim smithtim smith Member Posts: 2,313
    All metal except last few feet to register boots. Been our game for decades. Still fair amount of rec duct jobs too.
Sign In or Register to comment.


It looks like you're new here. If you want to get involved, click one of these buttons!