Results 1 to 10 of 10
  1. #1
    Join Date
    Apr 2009
    Posts
    9
    Post Likes

    Smelly return vent with brand new flex duct

    We have a park model trailer in Maine that is seasonal. Only open May to October. This past offseason the damn mice got into the ductwork. So just for some background on the trailer. There is one return vent that is flex duct that runs from inside of the trailer to underneath the trailer to I believe what is the air handler? The supply comes out of the air handler and goes into the bottom of the trailer, again this is flex duct. Those are the only two exposed ducts. All the other ducts are buried under the floor of the trailer and are made of some type of duct board. So I had a company come out and crawl under the trailer and replace the flexible return and supply ducts. I have also hired a company to come in and vacuum out the rest of the ducts that are buried under the floor. Somehow they will get to them from the supply vents. So we have not been able to use the AC/Heat because the duct cleaning company can't make it for another week. But I know the flex duct is new because I have crawled under the trailer and inspected it. No holes in it.

    But when we sit by the return vent in the house it smells like fish! That is what made me crawl under the trailer and inspect it. I figured the damn mice chewed another hole through it. But nothing. So is it possible that the lining of this
    flex duct stinks a bit until the unit actually runs for a while? The only other thing I can think of is that there was a mouse still in the house and when they replaced the flex duct it got trapped in there and died. But I have no way of telling this unless I crawl underneath, unhook the duct, and somehow inspect it. It is kind of a long return. Or I am hoping the duct cleaning company will have some sort of camera they can snake through to check?

    Has anyone else experienced this?

    Thanks,
    DB

  2. Likes DavidDeBord liked this post
  3. #2
    Join Date
    Mar 2015
    Location
    Hamersville, Ohio
    Posts
    2,442
    Post Likes
    First, ... Flex Duct is not designed for Out-door use, & it will quickly fall apart. And, "Flex Duct" as well as Metal Duct requires an adjustable "90", at both connections, & the Flex should be ran as evenly as possible, with very little sag in it.

    Second,... If the flex is coming from outside, ... then it should not be connected to a "Air handler" indoors, but instead a Floor Return.

    As far as the "odor", .. Some Flex pipe does have an odor, but, ... that odor generally quickly disappears.

    Perhaps you should have the air conditioner "Tuned & Cleaned", for if mice got in the Old flex, then it's also possible that they worked back to the Outdoor Unit, & made a Nest there.
    Hos 4:6 My people are destroyed for lack of knowledge. Because you have rejected knowledge, I will also reject you, that you may be no priest to me. Because you have forgotten your God’s law, I will also forget your children.


    "You've got to Stand for Something or You'll fall for anything" (A. Tippin)


    We are on a "Man-made Highway to Hell", Our so called "Leaders", Political & Religious, are encouraging The Mushroom like Sheeple to go faster.

    (AC-DC Lyrics)

  4. Likes kdean1 liked this post
  5. #3
    Join Date
    Apr 2009
    Posts
    9
    Post Likes
    Thread Starter
    Thanks for the reply. Ya I figured the flex duct wasn't designed for outdoor use. But all the trailers in the park are built this way. I wish I knew more about these things before buying it. I would have told them to not bother with the ducts and put in ductless splits. But too late for that right now. I wasn't sure what you meant with the adjustable "90" comment. I know coming out of the bottom of the trailer is some sheet metal thing where they zip tie the flexible duct to. And up they run it right on the ground under the trailer. The trailer
    is skirted so no rain/snow gets to it.

    I was also confused about your second point that the flex from outside should not be connected to an "Air Handler" indoors, but instead a floor return? I am a novice at this stuff so maybe I am using the wrong words. So under the trailer there is a metal large metal box that the flexible duct that runs on the ground goes to. So we have a floor return in the trailer. The flex duct is connected to that and run to the metal box. There is also a flexible supply duct that comes out of the metal box and goes into there trailer where I assume it hits the main trunk of the duct board ducts. In that metal box is where the AC coil is and something that looks like a hampster wheel. Is that the air handler or blower motor?

    In any event I need to check in that box and see if the mice made a nest in there. As you had suggested.

    Thanks,
    DB

  6. #4
    Join Date
    Mar 2015
    Location
    Hamersville, Ohio
    Posts
    2,442
    Post Likes
    " But all the trailers in the park are built this way."

    Many Wrongs, collectively do not make A Truth, nor something Right. That's what is wrong with th' World now.

    I recommend having Your Contractor install 26 G Metal, at the least Outside, & then applying Weather resistant Insulation over the Duct at the least.

    The 90 is adjustable,& it can be adjusted from a 90, to a straight fitting & it is attached via several sheet metal screw to a Metal collar that is anchored to your Duct. One Problem is that this has to be done carefully, & with the proper "Collar" due to your Duct being fiberglass.

    The 90s, ensure that the Flex-pipe doesn't collapse on itself while making the upward turn, as well as the full volume of conditioned air passes through.The Flex Pipe is connected to this 90. Also, depending upon the Local Building Authority, .....Sheet Metal Screws may be required to be installed in to the "Slinky" of the Flex, with the insulation Pulled up tight to the 90/ collar, then the outer cover, upon which the Zip Ties, or hanging wire, are then applied.

    Flex Pipe, is Not Approved for laying on the ground, ... It Will Rot Through, which will cause your having the same problem all over again. IT has to be suspended up from the ground by using a webbing, made for that purpose.

    "There is also a flexible supply duct that comes out of the metal box and goes into there trailer where I assume it hits the main trunk of the duct board ducts. In that metal box is where the AC coil is and something that looks like a hampster wheel. Is that the air handler or blower motor?

    Are You saying that Your Evaporator is not in the Outdoor Unit, that the Flex pipe is coming from?
    Hos 4:6 My people are destroyed for lack of knowledge. Because you have rejected knowledge, I will also reject you, that you may be no priest to me. Because you have forgotten your God’s law, I will also forget your children.


    "You've got to Stand for Something or You'll fall for anything" (A. Tippin)


    We are on a "Man-made Highway to Hell", Our so called "Leaders", Political & Religious, are encouraging The Mushroom like Sheeple to go faster.

    (AC-DC Lyrics)

  7. Likes kdean1 liked this post
  8. #5
    Join Date
    Mar 2013
    Location
    Billington Heights, NY
    Posts
    19,120
    Post Likes
    Fish is often the smell of new fiberglass. It should pass as time goes on.
    This forum requires that you wait 20 seconds between posts. Please try again in 50 seconds.

    Experience - knowing when to get the hell out of the way and plug your ears. "Don't be a sissy. Turn it on!"

    Pecmsg - "NEST should only be used with 3-M filters to guarantee total destruction of the equipment!"

    Poodle Head Mikey - "the world is well populated with the unknowing and the uncaring and the stupid."

  9. Likes DavidDeBord, JeffWil liked this post
  10. #6
    Join Date
    Apr 2003
    Location
    St. Louis
    Posts
    376
    Post Likes
    My house had about the same set up when i bought it. package unit, return 16" flex and i hard pipe the supplies from a metal trunk line to the grill s. Had the same problem with odor. After pulling out all the lined trunk line and runouts found mice had been everywhere. Problem solved- all the duct is gone package unit gone put in two mini split systems with three evaps each. From a 4 ton package heat pump to two two ton mini heat pumps. Zoned heat and ac quiet and the electric went down. Plus no stinking mice!

  11. Likes DavidDeBord liked this post
  12. #7
    Join Date
    Apr 2009
    Posts
    9
    Post Likes
    Thread Starter
    So it turns out that the smell is not only from the return. If you stick your face down by a supply register it stinks too. We opened up the outside unit where the "mouse wheel" thing is. There was no mouse turds or nests. So we are thinking it is coming from the ductwork under the floors in the trailer. That is the duct board, or whatever you call it. I'm not sure how do describe it. It is sort of like styrofoam, but that's not what it is. Looks like insulation that has some sort of thin membrane on it. So the theory now is that the pee soaked into this stuff and that is what stinks. I already had a company setup to come vacuum out the ducts this coming Tuesday. So I am going to go ahead with that. But I may be sealing off the registers and putting in a ductless mini split on the wall. What a nightmare. These little snots cost me a lot of money.

  13. #8
    Join Date
    Nov 2006
    Location
    Athens, Ohio
    Posts
    5,106
    Post Likes
    Has the unit been opened to inspect the coil?

    Additionally, does the flex duct size match the opening on the package unit? Or has the unit opening been covered with metal (or ductboard) and then a round collar installed for the flex duct? Ask yourself why the manufacturer makes a big opening? And what will happen when smaller duct is used?
    AOP Rules: Rules For Equipment Owners.

    Free online load calculator: http://www.loadcalc.net/


    There = not here. Their = possessive pronoun. They're = they are
    It's = contraction of it is. Its = the possessive form of it
    Too = also. To = expressing motion. Two = 2
    Then = after that, next. Than = indicates a comparison.
    Questions should end with a question mark "?" Statements end with a period "."

  14. Likes DavidDeBord liked this post
  15. #9
    Join Date
    Mar 2013
    Location
    Port St. Lucie, Fl
    Posts
    5,908
    Post Likes
    Quote Originally Posted by kdean1 View Post
    Has the unit been opened to inspect the coil?

    Additionally, does the flex duct size match the opening on the package unit? Or has the unit opening been covered with metal (or ductboard) and then a round collar installed for the flex duct? Ask yourself why the manufacturer makes a big opening. And what will happen when smaller duct is used?
    Undersized ducts - the number one cause of mouse pee odor?

    Sent from my Moto Z (2) using Tapatalk

  16. #10
    Join Date
    Nov 2006
    Location
    Athens, Ohio
    Posts
    5,106
    Post Likes
    No. I did say additionally because it is a different subject.
    AOP Rules: Rules For Equipment Owners.

    Free online load calculator: http://www.loadcalc.net/


    There = not here. Their = possessive pronoun. They're = they are
    It's = contraction of it is. Its = the possessive form of it
    Too = also. To = expressing motion. Two = 2
    Then = after that, next. Than = indicates a comparison.
    Questions should end with a question mark "?" Statements end with a period "."

  17. Likes DavidDeBord liked this post

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  

Related Forums

Plumbing Talks | Contractor MagazineThe place where Electrical professionals meet.