Thread: Vent tubes

I have 2 questions. I was at a 2 story home. Coming off of the HVAC supply trunk were four 2 inch flex lines (like the white dryer vent but smaller). They went up the wall between the back of the garage and the house. I could not find them in the attic. HVAC duct in the attic were easily identified. All second floor supplies were in the ceiling. I have an idea but looking for input. I should have put the home is about 15 years old.

A second thing was the attic had pink loose fill fiberglass. There was a granular material spread across the top. Kind of reminded me of corn meal. There was a can left from a bug bomb. I am thinking it is an insecticide. IS there any problem with that. Personally I wouldnt want it in my own home.

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As far as the flex lines it sounds like they may have used some Spacepak tubing to run a few feeds to difficult areas. If so, they probably won't get much CFM but maybe they don't need much. The small size of the spacepak tubes works because the system runs at higher velocity than a standard furnace.
As far as the attic insulation and insecticide I'd make a note in the report about it and suggest that testing might not be a bad idea. No much else you can really do.

I should add that the large master bathroom and master closet are over the garage. The master bedroom is above 1st floor living area.


The tubes are coming off a standard HVAC trunk line and would not be high volocity or pressure. Further I am sure there are not attached to a supply vent on either the first or second floors.

Since the master bath has a tile floor above a garage I am thinking this was someones dumb idea to provide heat under the floor.

As far as what I think could be insecticide is concerned. Since the house is not very air tight between the attic and living area would you consider it a possible health hazard. From anyones experience does this seem like an insecticide, possibly even something intended for a yard?

Originally Posted by Robert Hronek

... There was a granular material spread across the top. Kind of reminded me of corn meal. There was a can left from a bug bomb. I am thinking it is an insecticide. ...

Sounds like it may be ant bait

Originally Posted by Robert Hronek

Coming off of the HVAC supply trunk were four 2 inch flex lines (like the white dryer vent but smaller).

Originally Posted by Markus Keller

As far as the flex lines it sounds like they may have used some Spacepak tubing to run a few feeds to difficult areas.

Markus,

That was my first thought too, then I thought about the higher pressure for those SpacePak ducts and realized that they would not be coming off the main trunk line as that would not have the same higher pressure. The few (very few) SpacePak installations I've seen had those smaller high pressure ducts run all the way as the larger duct is not designed for that high pressure.

What are your thoughts on that?

The separation wall between garage and home, and the separation floor/ceiling assembly between garage and living space above shouldn't contain plastic flexible ducting communicating between garage and the residence, or between floors of the residence.There shouldn't be any plastic ducting in the attached garage either. 26 ga. metal for prescribed fire resistant construction (includes separation walls & structural floor/ceiling assemblies).

Not meant to be all inclusive, merely addresing the vaguely described situation (with admitted assumptions as to the descriptions offered) specifically the quoted & highlighted below.

Originally Posted by Robert Hronek

Coming off of the HVAC supply trunk were four 2 inch flex lines (like the white dryer vent but smaller). They went up the wall between the back of the garage and the house.

Originally Posted by Robert Hronek

I should add that the large master bathroom and master closet are over the garage

The trunk should be remediated.

Originally Posted by H.G. Watson, Sr.

The separation wall between garage and home, and the separation floor/ceiling assembly between garage and living space above shouldn't contain plastic flexible ducting communicating between garage and the residence, or between floors of the residence.There shouldn't be any plastic ducting in the attached garage either. 26 ga. metal for prescribed fire resistant construction (includes separation walls & structural floor/ceiling assemblies).

Originally Posted by Robert Hronek

Coming off of the HVAC supply trunk were four 2 inch flex lines (like the white dryer vent but smaller). They went up the wall between the back of the garage and the house.

Huh?

There is nothing wrong with having plastic air duct "between" (i.e., "within" the wall) the garage and the living space and/or "between" (i.e., "within" the floor system of the residence.

The separation requirement is that the separation be "on the garage side" of the wall and/or floor/ceiling system.

Once the 1/2 inch gypsum board is attached to the garage side of the wall studs and the underside of the floor joists, there is no restriction on having plastic air ducts in the wall, floor system, or in the attic.

You are correct that if a duct goes into the garage that the duct should be 26 gauge metal, 1 inch ductboard, or other approved material (i.e., does not have to be 26 gauge metal).

I should have elaborated on my 1st post. I wasn't implying that the tubes would work well on a conventional system. The small Spacepak tubes work on a spacepak system because of the higher pressures/velocity. I don't see them working well on a standard system, which is what it sounds like they have.
I'm figuring they used the tubes (whatever they are) because they didn't know any better, wanted to save space or money, etc.
Installed spacepak systems around here tend to have fairly limited length main trunklines and usually round pipe not rectangle. They are fairly common when people want to keep the boiler.
The idea they buried the lines under the floor to heat the floor sounds plausible. I've seen much weirder.

Materials exposed to the airflow in ceiling cavity plenums used for supply, return or exhaust air from the occupied area...Noncombustible, limited combustible, or have a flame spread index not exceeding 25 and a smoke-developed index not exceeding 50.Depends if the ventillation compartment is a duct, plenum or other defined area, and where (in what wall or structural floor/ceiling cavity, prescribed fire resistive construction) its located within, including load bearing or not exterior rated/insulated walls, or what may and may not penetrate required fire blocking, stops, etc. for a multi-level residence with attached conditioned or unconditioned garage space.The OP has not been specific enough to determine from his vague descriptions, despite Peck's asserted absolute conclusions/assumptions regarding membrane penetrations of prescriptive fire resistant constructed assemblies.

Originally Posted by H.G. Watson, Sr.

Materials exposed to the airflow in ceiling cavity plenums used for supply, return or exhaust air from the occupied area ...

Did I miss something in the post which said that was a plenum?

If so, please point it out to me.

If not, don't try another or your re-direction ploys for not admitting you are wrong - I thought you had out-grown those childish tactics.

Originally Posted by Jerry Peck

Did I miss something in the post which said that was a plenum?

If so, please point it out to me.

If not, don't try another or your re-direction ploys for not admitting you are wrong - I thought you had out-grown those childish tactics.

Saying "please" followed as you did obviously negates please, and frankly PECK it is obvious you are the only one displaying juvenile, infantile behavior.

NFPA 90B (Yep B, its a HVAC system in Omaha it supplies heat, the OP agreed/said so) includes Plenum in its Definitions:

Plenum:
A compartment or chamber to which one or more air ducts are connected and that forms part of the air distribution system.

He called it a "trunk", its a part of the Heating air distribution system supply side of the heating system and has four "ducts" connected to it.

He further said these "ducts" went UP (i.e. riser) and implied that they penetrated the ceiling or went UP in the WALL. The home has a second floor and some of the OCCUPIED space (MB closet and MB Bath) is above the garage. He said it was on the supply side. He further agreed the plastic/vinyl "duct" hoses were transporting HEAT and compared them with illegal dryer transition duct but narrower/smaller.

Coming off the HVAC supply trunk were four 2 inch flex lines (like the white dryer vent but smaller).

You even quoted that portion of one of his posts.


The system moves HEAT it is not a 90A system it is a 90B system. We know this because the OP said so.

Since the master bath has a tile floor above a garage I am thinking this was someones dumb idea to provide heat under the floor

In case you missed it again - that "floor" he's talking about is the second floor, above the "supply trunk" as he called it, on the first floor (questionable if in the home or attached garage). Obviously he wasn't technically precise (supply 'vents' not registers, etc.) in any of his descriptions, thus my reference to the vagueness of the 'word pictures'.

In the mean time Peck, knock off your vendetta, stalking, unprofessional, off-topic ad hominem.

WATSON,

Back to your so much crap ways again I see.

Originally Posted by Jerry Peck

Did I miss something in the post which said that was a plenum?

If so, please point it out to me.

Originally Posted by H.G. Watson, Sr.

Saying "please" followed as you did obviously negates please, and frankly PECK it is obvious you are the only one displaying juvenile, infantile behavior.

Yet again you did not point out where anything was said about a plenum, WATSON.

Your 'it's all about you' posts would be more helpful if you did not make stuff up when you respond to non-existent questions as though you were correct and then refuse to admit you were not, WATSON.

Here is just another example of it:

the ceiling or went UP in the WALL.

Correct - UP IN THE WALL ... which IS NOT a "plenum".

Not sure why you are the way you are WATSON, but your knowledge would be more helpful with fewer re-direction attempts when you are incorrect.

Originally Posted by Jerry Peck

WATSON,

Back to your so much crap ways again I see.





Yet again you did not point out where anything was said about a plenum, WATSON.

Your 'it's all about you' posts would be more helpful if you did not make stuff up when you respond to non-existent questions as though you were correct and then refuse to admit you were not, WATSON.

Here is just another example of it:


Correct - UP IN THE WALL ... which IS NOT a "plenum".

Not sure why you are the way you are WATSON, but your knowledge would be more helpful with fewer re-direction attempts when you are incorrect.

I pitty you Peck, you are having a days-long-tantrum and your own circuits are continuing to mis-fire. Take off your blinders. This is not a free standing cooled air only system. This 2-story home is in or near Omaha, Nebraska.

The OP referred to a "supply trunk" with "four ducts" plastic attached.

That TRUNK is a plenum. This plenum is obviously exposed.

That "SUPPLY TRUNK" as he called it is transporting HEATED AIR.

The uninsulated "white" plastic duct "that looks like dryer duct" is not permitted to be attached to the heated air supplying plenum.

It is not allowed to function as a "riser".

Even Air Connectors "shall not pass through floors".

See Chapter 4 of NFPA 90B.

Watson, if the OP was too vague for you, why don't you ask for clarification, rather than repeating again and again how vague it was?

In the mean time Peck, knock off your vendetta, stalking, unprofessional, off-topic ad hominem

That's rich, considering the number of times you've attacked me and others.

whoops!

Originally Posted by Kristi Silber

.
whoops!

.
But What About Me ?( pre whoops quote. )
.

I am not a fan of the high velocity air handling systems in a residential application, let alone a bastardized system attempting to incorporate high velocity duct with low velocity duct. It simply will not work and is a waste of money and offers nothing in the way of conditioning a home.

As far as the bug bomb and the granular stuff on the attic insulation, I don't think I would panic. Bug bombs are there to get rid of bugs, what home does not have bugs? If concerned have an exterminator come out and offer an opinion.

The OP wasn't too vague for me. It was PECK who had the comprehension, application, understanding, etc. melt-down.

Originally Posted by H.G. Watson, Sr.

The OP wasn't too vague for me. It was PECK who had the comprehension, application, understanding, etc. melt-down.

The original poster was clear to me apparently all but Watson in that the original poster was referring *ducts* passing through various areas, none of which were plenums.

When Watson erred, he went off on his typical tangent and started talking about what would be required when run through plenums - even though there was no plenum in the discussion.

Oh, well, that is Watson for you.