Duct Board or Duct?

[gonekuku]

For residential, what are the pros and cons of using duct board in unconditioned space? Obviously you need at least 1.5" to meet R6 and 2" for R8. Both probably have equal leak potential unless the workmanship is high.

Is it safe to say duct board means more labor, therefore it's more expensive and less used?

[Shophound]

Let's just say that in the real world, more often than not when you see duct board used, it's slapped in...and I'd say it's a safe thing to say it has a lower skill set requirement than sheet metal. Go to the Wall of Shame section of this site and see how many pics of hacked systems have fubar duct board plenums vs. sloppy sheet metal work.

Personally, if the unconditioned space you're referring to is an attic, it's the dumbest place to put HVAC ductwork, regardless of type and R value. The building construction or budget does not always allow for ductwork in the conditioned space, but I'd sure fight for it over an attic any day if I were making design decisions.

[ChitownTech]

I just moved back to Chicago from Florida were 95% of all installs are done with duct board and in the attic. It is very easy to install but also very easy to screw up. It is more forgiving than metal so therefore can be put in much easier with staples and metal tape. The 1.5 inch thick duct board will give you the r6 rating which is adequate for attic installations. Also duct board over time does deteriorate and once dirty from use can never be trully cleaned, just something to think about.

[sadlier]

Cons: Ductboard costs more than metal; Installed with iron-on tape, ductboard takes longer to make and install; 1.5" and 2" ductboard is hard to find, especially the black ductboard (1" can be insulated with bubble wrap for R-8); Ductboard is prone to damage whenever someone crawls across it; Taps are typically limited to only straigt pipe rather than high efficiency fittings; It is easier to hang metal than ductboard ducts.
Pros: Ductboard systems are quieter; Ductboard is easier to field-fabricate; Properly installed ductboard has less leakage than metal duct; Ductboard is easier to cut and repair than metal duct (in case you have to get inside the duct).

[Carnak]

Ductboard will be a lot more air tight. If you are used to working with it it is a lot faster than galvanized that you have to insulate.

The guys here make angled take offs for rectangular branches and they are working with hand tools.

[gonekuku]

Thanks for the feedback.

It's obvious that there is a cost/quality/efficiency relationship.

Because the builder has to remain competitive, it is common that a low bidder with the least geometrically skilled workers gets to cut and tape the ductboard....and then the homeowner pays 25% more for heating and cooling for 30 years.

I'm not complaining, just observing marketplace supply/demand.

[coolguysfl]

Thanks for the feedback.

It's obvious that there is a cost/quality/efficiency relationship.

Because the builder has to remain competitive, it is common that a low bidder with the least geometrically skilled workers gets to cut and tape the ductboard....and then the homeowner pays 25% more for heating and cooling for 30 years.

I'm not complaining, just observing marketplace supply/demand.

25% more for heating & cooling?

Not sure where you're collecting data... but that's nonsense. PROPERLY installed, be it board or metal will not vary in performance.

If you want to save on heating & cooling DEMAND your duct work be in the conditioned space - not the inferno & freezer of an attic or crawl space - then you can take 15% right off the top of your demand needs.

[gonekuku]

You said it "Properly Installed".

I was wrong, the average ducted system leaks only 20% according to the government.

http://www.energystar.gov/index.cfm?c=home_sealing.hm_improvement_sealing

[voleye]

Just my preference. We dont use ductboard for anything. Do a search on yahoo or google about fiberglass litigation. I know that if it installed properly it is not supposed to break down and become airborn. But as a company we have choosen not to expose our company to the asbestos of the 2000's. Just a company/personal choice.

[Green Mountain]

Our business is in a small town. If you don't do good work word gets around very quickly.

We have been selling ductboard systems for 20 years. However the systems we sell are all shiplap cuts by a machine. The seams are stapled and taped and squeegied. If it is below 50°F the taped joints are heated and then squeegied.

If you want to do a ductboard job correctly then get a hold a copy of the "SMACNA Manual for fiberous duct construction."

[dajw02]

from my experience on things, most 2" DB here in florida are used in Commercial apllications, 1.5" is approved for residential. But exposed metal is cheaper than Db, but when you put the cost of insulating the metal- in which you have to do, and add the extra lobor needed to install metal then- do a metal system is more expensive by far. Plus to add more flame to the fire it is difficult to find a residential crew in florida that knows how to install metal duct.

David W.

[Carnak]

knauf koolduct is the best of bothworlds. Very air tight, just costs easily as much as commercial galvanized, installed and insulated by true pros, niot hacks slapping the stuff in and collecting a fast pay cheque.

[gonekuku]

Just looked at the specs for knauf koolduct - It's faced on both sides so blowing fiber particles or growing mold should not be an issue. Their R8.5 is only 1 3/32" thick. Good stuff. Funny thickness, so proper tools and planning are obvious requirements.

Voleye, I looked at the fiber litigation - scary stuff.

[Carnak]

The commercial system of joints is up there with ductmate in my books. I scoffed at the residential joint system, but gave it the torture test and was stronger than cleats.

[voleye]

[QUOTE=acefurnacefixer;1325219]Thats the outright dumbest thing Ive ever heard anyone say about ductboard.


Maybe so. But Ill bet that asbesto's was popular when it was being put in. Dosnt mean its right. Just look under fiberglass lawsuits. Why would you install something like that.

[comfortairtech]

Thanks for the feedback.

It's obvious that there is a cost/quality/efficiency relationship.

Because the builder has to remain competitive, it is common that a low bidder with the least geometrically skilled workers gets to cut and tape the ductboard....and then the homeowner pays 25% more for heating and cooling for 30 years.

I'm not complaining, just observing marketplace supply/demand.

If you don't mind inhailing microscopic fiberglass particles go right ahead and install ductboard.

[gfp777]

Let's just say that in the real world, more often than not when you see duct board used, it's slapped in...and I'd say it's a safe thing to say it has a lower skill set requirement than sheet metal. Go to the Wall of Shame section of this site and see how many pics of hacked systems have fubar duct board plenums vs. sloppy sheet metal work.

Personally, if the unconditioned space you're referring to is an attic, it's the dumbest place to put HVAC ductwork, regardless of type and R value. The building construction or budget does not always allow for ductwork in the conditioned space, but I'd sure fight for it over an attic any day if I were making design decisions.

I Agree give me ductwork (metal only) prefferably round spiral I know , hard to install in Residential

[cra]

hello to all i have a ? what should be your frist cut when use 1.5 duct board

[Special Ed]

I'll install metal ductwork in an existing home IF the HO is willing to rip-out their ceilings, they move out for a couple days & allow me to do my thing. Then the HO's should be willing to pay for the ceiling repairs & to re-insulate the attic.

OR....

The HO can allow me to properly install a combo ductboard/flex duct system. It'll cost less & it won't be necessary to demo a ceiling.

Their choice.

[Kevin O'Neill]

Properly designed, sized and installed, ductboard is a wonderful thing. The new stuff is coated on the inside with a biocide to retard mold. It is also smoother than the old duct board and less likely to shed like the old stuff did.

[ArtieNJ]

http://koolduct.knaufusa.com/nolonger/

[Southern Mech]

I rarely use ductboard, 90% is round pipe trunk with flex, 7% rectangle metal and 3% ductboard. I don't want it in my house and won't sell to someone, I only use in rarity for a loud short return, or on C/O to tie in exhisting DB system.

[genduct]

Ductboard is a COMMERCIAL PRODUCT used in a residential system, So your question is??

Too bad untrained people are allowed to buy the material, butcher it up and give the material a bad rep.
We have fabricated millions of Square Feet of material for 2X millions of square feet of schools, churches and mostly office or retail space in our 30 years of business.
Ductboard is 1/8 the leakage of a SEALED residential supply duct and 1/16 of the expected leakage of a SEALED residential return.
If you doubt that look up the leak class standards for duct in Man D or J Sply 48 and return 96 vs DB 6
Hey Southern that the same leakage as flex with 1/2 the friction is flex installed correctly or 1/4 the friction if installed as usual. Also consider the surface area and heat duct transfer of the flex home runs vs a DB trunk with flex branch runouts and tell me that the customer is not better served with the trunk and branch layout

[ga-hvac-tech]

The 'old' ductboard (not lined inside) could shed fibers... not a good thing IMO. I generally use the new ductboard (inside is sealed and bio-treated) for return plenums and occasionally for transitions when the job price is tight...

I prefer metal duct after the air filter if the job has the $$$ to do so.

[genduct]

Hello GA, I have been hearing about fiber erosion for 30 years and have yet to see an example. Am going to do a field visit to a NJ Schools we fabricated in 1993 right after the new year. Usually if there is any duct on the inside of the duct, it clearly shows there is no eroison.

If you see a job can you get some pics of better a sample. I'll pay for the postage.

Mike

[hivacer]

round metal pipe, tape the joints and seams, slide foil flex over for insulation, mark saddle locations cut and screw over flex into round pipe, flex for branch runs, only way to go everything is prefab and goes together quick and easy

[the dangling wrangler]

Ductboard is a COMMERCIAL PRODUCT used in a residential system, So your question is??

Too bad untrained people are allowed to buy the material, butcher it up and give the material a bad rep.
We have fabricated millions of Square Feet of material for 2X millions of square feet of schools, churches and mostly office or retail space in our 30 years of business.
Ductboard is 1/8 the leakage of a SEALED residential supply duct and 1/16 of the expected leakage of a SEALED residential return.
If you doubt that look up the leak class standards for duct in Man D or J Sply 48 and return 96 vs DB 6
Hey Southern that the same leakage as flex with 1/2 the friction is flex installed correctly or 1/4 the friction if installed as usual. Also consider the surface area and heat duct transfer of the flex home runs vs a DB trunk with flex branch runouts and tell me that the customer is not better served with the trunk and branch layout

Hey Mike, isn't this deja vu all over again?

[genduct]

Well Cowboy, seems some things never change, do they? Probably need that beating a dead horse icon.
How's by you? Hope Christmas and especially the new Year is good to you and yours

Best from Mike and like our license plates used to say
" You got a friend in Pennsylvania"

[the dangling wrangler]

Well Cowboy, seems some things never change, do they? Probably need that beating a dead horse icon.
How's by you? Hope Christmas and especially the new Year is good to you and yours

Best from Mike and like our license plates used to say
" You got a friend in Pennsylvania"

It's not worth the horse icon anymore. So, if you see me post this, you'll know what it means then.

Did "they" really pull that saying? To be PC, I suppose.


http://i52.tinypic.com/2qle2bq.jpg

Happy Festivus Mike.

[ga-hvac-tech]

Hello GA, I have been hearing about fiber erosion for 30 years and have yet to see an example. Am going to do a field visit to a NJ Schools we fabricated in 1993 right after the new year. Usually if there is any duct on the inside of the duct, it clearly shows there is no eroison.

If you see a job can you get some pics of better a sample. I'll pay for the postage.

Mike

Back in 2006, I did sales for a HD (Trane) contractor. One of the 'tricks' they taught us was to have a piece of 'old style' ductboard in a sandwich baggie available. If the existing system had any ductboard, I was supposed to take out the piece and discuss it... while handling it over a dark surface... all the while there were little fibers falling on the dark surface. Then show the dark surface to the customer and ask them if they thought it was a good idea to breathe that stuff... Or play the guilt trip of asking if it was a good idea for their kids to be breathing the stuff...

I fully realize this is an old 'sales trick'... and there are no hands rubbing the ductboard in an installed system. Around my area, folks generally think of ductboard as 'bad'... Metal ductwork tends to 'sell itself' so to say.

I have seen numerous installs where the ductboard became water-logged, and moldy... Not a good thing IMO.

My company policy is to not use ductboard after the air filter unless the budget will not allow metal. Most of my customers seem to agree, so that is the way I do installs.

BTW: If I get some pictures and you want them, I could Email the files to you... however with ductboard not being popular... I probably will only see older installs.

[ga-hvac-tech]

It's not worth the horse icon anymore. So, if you see me post this, you'll know what it means then.

Did "they" really pull that saying? To be PC, I suppose.


http://i52.tinypic.com/2qle2bq.jpg

Happy Festivus Mike.

:deadhorse::deadhorse::deadhorse::deadhorse::deadh orse:

[supertek65]

in 1988 we had an explosion that killed 6 firemen!
It was terrible!

I have an account 40 miles from the explosion!
All duct board about 20k sq ft

every single piece of duct board and every ceiling tile fell down!!!!!!!!!!!!!!!!!!!!!!!!

nice repair!



http://3.bp.blogspot.com/_oLCtkQVQO-M/TPRd-0w1xVI/AAAAAAAACQ0/mjNN4PT33AU/s1600/1988Explosion1.JPG

[supertek65]

hi Ga
hi DW

[ga-hvac-tech]

hi Ga
hi DW

Hey ST65,

How's it goin' up your way?

Weather down here is about normal for the season.

Did you guys/gals decorate the bar for Christmas?

[the dangling wrangler]

in 1988 we had an explosion that killed 6 firemen!
It was terrible!

I have an account 40 miles from the explosion!
All duct board about 20k sq ft

every single piece of duct board and every ceiling tile fell down!!!!!!!!!!!!!!!!!!!!!!!!

nice repair!



http://3.bp.blogspot.com/_oLCtkQVQO-M/TPRd-0w1xVI/AAAAAAAACQ0/mjNN4PT33AU/s1600/1988Explosion1.JPG



So, where can a man buy some of that there explosion proof metal duct these days?

[the dangling wrangler]

hi Ga
hi DW

Howdy Franklin.

[supertek65]

things are good! I worked 6 hrs today, just enough to ruin my day!

I know your weather is about 100 degrees!!!!!!!!!!!!

it is like 10 degrees here!

My beautiful daughter decorated the bar, Hell I just got our fake tree up yesterday!







Hey ST65,

How's it goin' up your way?

Weather down here is about normal for the season.

Did you guys/gals decorate the bar for Christmas?

[supertek65]

well you have to pay alittle extra for it, but I got some!









So, where can a man buy some of that there explosion proof metal duct these days?

[supertek65]

have you guys seen the 23 year old Big chiller mechanic/ lead technician that nobody has ever out troubleshot yet???????????????????????????????

[supertek65]

by ANTHONYAC1


people argue with me about why i dnt get my journeymans lisence. i tell them i rather keep studying and get better at trouble shooting. im 22 years old with 3 years field experience. everyone braggs about their journeyman techs. dont get me wrong its a good accomplishment and sumthn to be proud of. I worked with several journeyman that there age range is plus or minus 40 years old and still have not ran into 1 that can out trouble shoot me. it looks to me people buy there journeyman card these days.. Dont know how but i here its possible.. my question is whats more valuable a skilled tech or a journeyman tech.

[supertek65]

i went to tech school for about a year and a half. Got an interview with this commercial company the guy interviewed me he said he will call me by saturday he has a few others to look at. saturday came i called to follow up he said he liked my drive for the opening position and he will give me a chance. now i have been wrking for the same company 3 years being the lead tech at 22 years young we do ice machines, chillers, cooling towers, a/c, and refrigeration. #1 thing like you have already stated you must get the field experience. go out there like a sponge and absorb it all. once you know sumthn no one can take it away from you.

[ga-hvac-tech]

things are good! I worked 6 hrs today, just enough to ruin my day!

I know your weather is about 100 degrees!!!!!!!!!!!!

it is like 10 degrees here!

My beautiful daughter decorated the bar, Hell I just got our fake tree up yesterday!

I wish it was 100D outside, I would be buried in AC calls... :)

Check the weather channel for zip code 30071, that will tell you what it is here.

And as for the bar: :worthless:(Just HAD to do that... :LOL:)

[ga-hvac-tech]

i went to tech school for about a year and a half. Got an interview with this commercial company the guy interviewed me he said he will call me by saturday he has a few others to look at. saturday came i called to follow up he said he liked my drive for the opening position and he will give me a chance. now i have been wrking for the same company 3 years being the lead tech at 22 years young we do ice machines, chillers, cooling towers, a/c, and refrigeration. #1 thing like you have already stated you must get the field experience. go out there like a sponge and absorb it all. once you know sumthn no one can take it away from you.

Tell you what ST; this kid will go a LONG way if he keeps his head on his shoulders. I wish more folks in the trades had this good of an attitude.

[supertek65]

34°F | °C
Current: Partly Cloudy
Wind: N at 0 mph
Humidity: 87%Sat

42°F | 29°FSun

48°F | 27°FMon

52°F | 34°FTue

55°F | 38°F

[supertek65]

where I work he would get a blanket party!







Tell you what ST; this kid will go a LONG way if he keeps his head on his shoulders. I wish more folks in the trades had this good of an attitude.

[supertek65]

LOL!!!!!!!!!!!!!!!!!!!

I am cursed with being surrounded by beautiful women!!!!!!!!!!!!!!!!!!

ofcourse with 5 sisters, 5 daughters, 13 neices and a grandaughter?

A bar full of women, usually biker babes and 12 bartenders!!!!!!!!!!!!!!!!!!

my life sucks!!!!!!!!!!!!!!!!!!!!!!














I wish it was 100D outside, I would be buried in AC calls... :)

Check the weather channel for zip code 30071, that will tell you what it is here.

And as for the bar: :worthless:(Just HAD to do that... :LOL:)

[ga-hvac-tech]

34°F | °C
Current: Partly Cloudy
Wind: N at 0 mph
Humidity: 87%Sat

42°F | 29°FSun

48°F | 27°FMon

52°F | 34°FTue

55°F | 38°F

Give or take, this is about normal for around here this time of the year.

We had COLD weather last week, broke a record low on Mon the 13th... Old record was 15, new record is 14, at my home was 13. My DF system never missed a beat and the house was comfy the whole time.

[ga-hvac-tech]

LOL!!!!!!!!!!!!!!!!!!!

I am cursed with being surrounded by beautiful women!!!!!!!!!!!!!!!!!!

ofcourse with 5 sisters, 5 daughters, 13 neices and a grandaughter?

A bar full of women, usually biker babes and 12 bartenders!!!!!!!!!!!!!!!!!!

my life sucks!!!!!!!!!!!!!!!!!!!!!!

You aint got nothin to complain about dude... :patriot:

And I understand if you do not post any pics with all that scenery to protect... :)

[supertek65]

LOL!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!:bsing:




You aint got nothin to complain about dude... :patriot:

And I understand if you do not post any pics with all that scenery to protect... :)

[Lash]

34°F | °C
Current: Partly Cloudy
Wind: N at 0 mph
Humidity: 87%Sat

42°F | 29°FSun

48°F | 27°FMon

52°F | 34°FTue

55°F | 38°F



Dang. That looks like a heat wave compared to these parts.

[supertek65]

yeah! that would be a heatwave in kc too!!!!!!!!!!!













Dang. That looks like a heat wave compared to these parts.

[genduct]

Yes they did! Too bad i thought it said a lot about "Us Guys" from PA.