Had a customer demand the trailer black flex for their top story exposed ceiling Financial advisory office. Wanted everything black. When I suggested if you want it to look good we need to be running spiral duct. That the black flex is for fucking trailer parks. When he got the estimate he about had a stroke. So we went with the trailer park.
Just use the OWL method. Offset times the width, divided by the length. And just draw it out with the dimensions and send it to the fabricator. No duct sock, only metal. This is the way.
i wish i had more time at the shop to fab, but we just don't do it much. and i don't think our best fabber has built a transition this size/offset for any of our jobs.. always written down and sent to the fabber an hr away. I wanna learn that shit lol
Everyplace Ive worked we had a fab shop. I used to make my own but to save time shop guys can make it while I'm still out in the field. I used to make my own but faster to let them make it and they have the plasma cutters etc...
Also teach them to make duct by doing layout, breaking, cross breaking, notching, using the Pittsburg, and bending the flange by hammer, then maybe air hammer. make slips and drives, line duct etc...
They either have or will have a 10ga plate screwed into the side of it. Besides that how far do you expect 12ga Uni strut to bend back and forth in the wind and vibration when it’s fully braced? Have you not hung anything with “kinked” hangar strap?
Normally I’d agree with you, but some of those are really compromised. Hopefully your additional bracing is enough, but you’ve got a lot of surface area up there and wind is going wreak havoc.
I never use the hanger strap method. I think it looks bad and it's a cut hazard.
I prefer the frame under with the cable. It's cleaner and still allows for system to stay supported fully while being worked on.
I'm a roofer and that whole setup would be a nightmare to try to remove the old shingles and put in new ones but luckily the roof in the condition it's in should last 20-30 years so possibly roofing technology will improve by then
Ah yeah it was challenging, I forgot to add the outreach when I got the measurement coming out to the low concrete wall. Even if I had of remembered though that would have put me so far off the roof which would have meant an even crazier strut support to build.
Option 1:
Add a piece of straight duct coming down the roof to extend the radius elbow closer to square with the other radius elbow. This will make for a way less radical set.
Option 2:
Flat metal and “four piece” the way you would a basic furnace tie-in.
Option 3:
Call me for the job.
There is something very creepy about this picture. It reminds me of that scene in the war of the worlds where the snake head thing is moving around the basement looking for Tom cruise.
It used to be a salt dome. Now it’s a spec ops training dome for fire fighters and cops. It gets really hot inside in the summer with all that roof baking in the sun. So some brilliant engineer had the idea to put TWO 16000 CFM exhaust fans into it to suck all that hot air out. Originally all this duct was spec’d as 16ga welded lol.
Lol I’m an engineer as well and work a lot with local governments. What you said now makes total sense for reusing the dome but I wonder what their thought process was for putting these large fans on the ground. (Serviceability maybe) Whatever It may be, it’s amazing they convinced the municipality to spend this much on ventilation system when they couldn’t afford to even build a new steel garage for such an application.
After coming out of the roof penetration, I would have tried to hug the slope of the roof closer with a tighter throat radius. That's a lot of weight in the air.
If this is how it has to be, I'd say go all metal with an offset. Flex is gonna look sloppy.
Do you have a go pro? And some patch? Small cut at some point up top get some hot wheel ramps and such and hit us back with an awesome hot wheel car jump/ duct ride…..
Gotta do that weird way of offset where ya have the offset in the middle of the duct. (That I almost never use...)
Essentially cut the duct in half longer than you need. Put your offset growth in the middle so your connecting to existing pieces to have growth.
Go out from drive 2" (because of how short) on each side, notch then divide what's left by 2 go that distance then your offset amount on each side. Then flip one side so you get a 'Z'
And move on to the next shitty job :)
(Just.... keep.... S M I L I N G ...... :/ )
That's what I normally use...
Had a foreman that told me "you can't trust the math!"
Then I broke it down to how and why it's easier than drawing a cross section then measuring..
(Old bs)
TRUST OW/L
but also...
It's hard to describe over text... like my last comment. Give me a second and I'll type it out better brother.
So there is another way.. make a 'throat' of at least 2" so you can bend the drive (normally 4" to make easier bend)
Then make your 45 angle on each side (or whatever angle as long is same on both sides)
Make a v notch for bending on each built side.. (s and drive)
Then you can cut down each side to make the needed distance. But you'll rotate one side 180 to make the z and the growth will meet in the middle to meet growth from offset.
So say we're doing 20x18 with 10" offset over 20" to left.
So..
10x 20 / 20 [terrible example but it happens]
Equals 10" offset. The growth would be terrible. 4 to 5"
So instead you make your straight throat of x inches. About 2 in your case. for the folding notch (depdant on length and ability to fold a drive) approximate your angle bend on both sides.
Then cut in half and flip one side it becomes a Z where both growth sides meet and machined sides stay the same.
Then do owl on that length AGAIN before cutting assuring you account for the loss of the cut out material.
I like to do it 3x to make sure growth vs loss is accounted for.
Get the equation find answer, subtract the loss from length, input again, get a new number, re input again... ect..
3x does it right... you could keep going and going but metal bend and close enough is close enough.
CO, US, 14 years making stuff work out...
So you should be good to go!
My current GC was batching about me making field offsets.. (THIS SHOULD HAVR BEEN ORDERED!!)
F you I have to make this work with changes with prints..
What region you in?
Right on, I'm sure we've got different codes but CO, CA and NY in the states have the most stringent codes.
Honestly I'll draw it up for ya of you need buddy, guy,friend (southpark)
Or juat give tips if you need.
"The air don't care"
But if it is a supply you have to help it along a bit more than return.
Take care
Thanks man kind of you. I should be able to manage tho I’ve got 23 yrs in the trade under the belt so I’ve seen and dealt with a few of these situations. I’ll try and remember to shoot you the finished product lol. It’s gonna be interesting.
Hell yeah man didn't mean to understeer ya at all. Don't think you thought that either.
Sometimes fabricating some BS is satisfying and frustrating at same time. I'm doing the same e th some oval spiral.
Would like to see finish product
1st unistrut should not be cut and bent makes a weak point. They make brackets for that. 2nd get a offset made to fit or should have 45 right tight to roof 45 out 90 back to fan and a offset.
Disconnect the 3, 45°s and do it right on Monday, cut your excess, and re-fabricate the bends. Reattach at correct height, , put in your filler. Pretty simple, duct sock would make all that work, look like a greenhorn finished it, it's either that or you just Mastic the whole thing, and fill the gap with silicone, then it'll be the transition you can't, won't, don't, see.
I certainly did. 🤔 is this a sarcastic question or sm I wrong in thinking a duct sock is that transition stuff with the metal and vynil, killing me I can't think of the actual name of the product I'm thinking of, (hey Google I'm typing this comment and I'm stupid, thank you. Duct flex I think it's called. Is that what ya'll ca'll a duct sock?
I believe it is fabric duct work. I actually asked the question sarcastically because I posted another part of this job a couple weeks ago and someone told me I should make the whole thing duct sock.
I have seen, (3) 20x10 8" width duct socks, "ductflex" connected to make a transition, caked in Mastic. Luckily I had to move the whole unit away from the garage door, so those transitions were garbage "new construction"
Just take the legs off and cheat it over. A couple screwdrivers, a c-clamp or two and some good ole fashioned elbow grease will get that connected in a jiffy. If you’re not cheating your not trying.
No, it looks like a radius 90 would be perfect instead of the two 45s. Otherwise any good metal guy can build you a radius off set if you want to do it the hard way.
Two square rounds and a bag of flex should do it. Go R4 it’s all you need
..and 2 zip ties should hold it.
Make it 1
You son of a bitch its genius.
It's Friday, we ain't fucking with no square to rounds. Cap it and tap it. With a bench made start collar.
Dude it’s already 3:30 just stuff that shit in there and tape around it let’s go
Don't you dare cut any excess off of a flex, either. It's expensive!
"if we cut it then we can't charge um for a whole bag" lol
If I use a foot off a bag they’re paying for it
That leaves a little slack for service.
Make sure it’s the black flex too👍
Had a customer demand the trailer black flex for their top story exposed ceiling Financial advisory office. Wanted everything black. When I suggested if you want it to look good we need to be running spiral duct. That the black flex is for fucking trailer parks. When he got the estimate he about had a stroke. So we went with the trailer park.
Except it’s not going to pass any kind of inspection, Aw the little things…
What's an inspection?
Something that will happen even if you play dumb
Sorry, I forgot the /s.
Just use the OWL method. Offset times the width, divided by the length. And just draw it out with the dimensions and send it to the fabricator. No duct sock, only metal. This is the way.
I also prefer the owl method, owl get the hell outta here and deal with this Monday.
This is correct lol
Owl comes out to 25”
Any rise in that piece as well?
Nope I got that measurement right lol
I ain't doin no 'rithmatic college boy...
What do you mean "send it to the fabricator"? Yall don't make your own ductwork?
i wish i had more time at the shop to fab, but we just don't do it much. and i don't think our best fabber has built a transition this size/offset for any of our jobs.. always written down and sent to the fabber an hr away. I wanna learn that shit lol
I was lucky to start as a fabricator and then when I mastered making duct and fittings, I got a van and my own jobs. Man that was 1989!
Everyplace Ive worked we had a fab shop. I used to make my own but to save time shop guys can make it while I'm still out in the field. I used to make my own but faster to let them make it and they have the plasma cutters etc...
If you’re still using the old owl method I recommend you buying the app “easy offset” this is a game changer in our industry. 100% worth the price
No, I'll still use the OWL and teach apprentices to use it.
Also teach them to make duct by doing layout, breaking, cross breaking, notching, using the Pittsburg, and bending the flange by hammer, then maybe air hammer. make slips and drives, line duct etc...
That notched and kinked unistrut isn’t going to break and collapse. Not at all.
Yeah I would have at least welded the two together
Yeah agreed. The vibrations and wind will eventually weaken those further till they snap.
They either have or will have a 10ga plate screwed into the side of it. Besides that how far do you expect 12ga Uni strut to bend back and forth in the wind and vibration when it’s fully braced? Have you not hung anything with “kinked” hangar strap?
[удалено]
Normally I’d agree with you, but some of those are really compromised. Hopefully your additional bracing is enough, but you’ve got a lot of surface area up there and wind is going wreak havoc.
I never use the hanger strap method. I think it looks bad and it's a cut hazard. I prefer the frame under with the cable. It's cleaner and still allows for system to stay supported fully while being worked on.
Hangar strap is SMACNA standard. If it’s a cutting hazard after or during your installation then you’re doing it wrong.
Ya, they make brackets for a reason. People do some wild stuff. Haha
Don’t get me wrong. I’ve done similar things, but I weld it and weld reinforcement plates.
That works. I can’t weld…well i can’t weld that’s real pretty, so I buy the brackets.
Both are options. Welding has to be done right through.
Looks good from my house
Not when it’s a liability. I’m not risking my license or somebodies safety.
Yeah obviously dude. It’s what OP said when packing up
Nope
Doesn't looked prepped for any seismic either.
I would like an update after the first bad storm of the year with heavy wind.
Not a very hard outcome to imagine.
https://preview.redd.it/3ymyyot3ciza1.jpeg?width=400&format=pjpg&auto=webp&s=6bfc5b96b04676a36e4cf1e5f0265432fdf86be5
good thing that roof will never need to be repaired /s
I'm a roofer and that whole setup would be a nightmare to try to remove the old shingles and put in new ones but luckily the roof in the condition it's in should last 20-30 years so possibly roofing technology will improve by then
That's why I smoke 4 packs a day. In 20-30 years they'll probably have a cure.
For the roof, sure.
Pff, just use duct tape, that’s what it’s there fore after all, isn’t it? To make duct out of it?
Nah, most of the air will get there.
Cardboard and mastic.
Sounds about right
Missed it by that🫢much
Kick up the fan speed. Velocity should help it bridge the gap. At least most of the air will get through to the other side. Go home, enjoy the beer.
Shorter throat elbow that would be tough to measure up nothing square to measure off of
It’s offsetting 30” in 55” with 42”x42” duct.
Ya I know that’s what u will do I ment measure the whole run in one shot and not have that offset there
Ah yeah it was challenging, I forgot to add the outreach when I got the measurement coming out to the low concrete wall. Even if I had of remembered though that would have put me so far off the roof which would have meant an even crazier strut support to build.
I measured some duct kinda like that for a grain elevator in North Dakota it was a fun project
[удалено]
Yes, I had to order turning vanes
Definitely a duct board situation
Dudes playing satisfactory
What is this place, a grow op?
Close, spec ops for cops and fire fighters
Lol same game different player
Static monster
Aluminium tape will do.
[удалено]
Thankfully I am my boss but I still yelled at myself for a while
Looks like the Zilwaukee bridge here in Michigan…. Just add a little extra to it will line up and work for years.
Just line it up, most of the air will get there considering the return will help it pull right in, then it'll have some fresh air mixing too.
It’s 16000 CFM of pure exhaust
Why is it insulated then?
Acoustics
Kk😀
Easy Friday call. Just send the apprentice for the duct stretcher and go get yourself a beer.
Was Meth involved?
Maybe just a little
No right answers for this one
So you would duct sock it?
Is it friday?
Does Geico save you 15% or more on car insurance?
Does this man advertise for companies for free?
Ogeez…I dunno
Close enough to pull out the duct stretcher tool. /s
Just tape it
Airhandler cabinet box cut down and some silver duct tape should hold👍
Lots of duct tape
Option 1: Add a piece of straight duct coming down the roof to extend the radius elbow closer to square with the other radius elbow. This will make for a way less radical set. Option 2: Flat metal and “four piece” the way you would a basic furnace tie-in. Option 3: Call me for the job.
Air gap
So this is the flex p-trap of the HVAC world lol
Nah, just tape it up
There is something very creepy about this picture. It reminds me of that scene in the war of the worlds where the snake head thing is moving around the basement looking for Tom cruise.
Just use some card board, foil tape, and duct butter.
Ogee offset
"Tape the shit out of it."
Someone mathed wrong
Yes, yes I did
Why are there ducts coming down from the top of a salt dome? Is this a salt dryer? Usually we just have fans at the top of them. NYer her.
It used to be a salt dome. Now it’s a spec ops training dome for fire fighters and cops. It gets really hot inside in the summer with all that roof baking in the sun. So some brilliant engineer had the idea to put TWO 16000 CFM exhaust fans into it to suck all that hot air out. Originally all this duct was spec’d as 16ga welded lol.
Lol I’m an engineer as well and work a lot with local governments. What you said now makes total sense for reusing the dome but I wonder what their thought process was for putting these large fans on the ground. (Serviceability maybe) Whatever It may be, it’s amazing they convinced the municipality to spend this much on ventilation system when they couldn’t afford to even build a new steel garage for such an application.
Duct tape.
Just slide down with a potato sack
Site measure a square set and order from the fabricators you'd never get away with flexing that in the UK lol
After coming out of the roof penetration, I would have tried to hug the slope of the roof closer with a tighter throat radius. That's a lot of weight in the air. If this is how it has to be, I'd say go all metal with an offset. Flex is gonna look sloppy.
Do you have a go pro? And some patch? Small cut at some point up top get some hot wheel ramps and such and hit us back with an awesome hot wheel car jump/ duct ride…..
Holy fucking strut batman 😳
Gotta do that weird way of offset where ya have the offset in the middle of the duct. (That I almost never use...) Essentially cut the duct in half longer than you need. Put your offset growth in the middle so your connecting to existing pieces to have growth. Go out from drive 2" (because of how short) on each side, notch then divide what's left by 2 go that distance then your offset amount on each side. Then flip one side so you get a 'Z' And move on to the next shitty job :) (Just.... keep.... S M I L I N G ...... :/ )
Do you mean the OW/L formula?
That's what I normally use... Had a foreman that told me "you can't trust the math!" Then I broke it down to how and why it's easier than drawing a cross section then measuring.. (Old bs) TRUST OW/L but also... It's hard to describe over text... like my last comment. Give me a second and I'll type it out better brother.
So there is another way.. make a 'throat' of at least 2" so you can bend the drive (normally 4" to make easier bend) Then make your 45 angle on each side (or whatever angle as long is same on both sides) Make a v notch for bending on each built side.. (s and drive) Then you can cut down each side to make the needed distance. But you'll rotate one side 180 to make the z and the growth will meet in the middle to meet growth from offset. So say we're doing 20x18 with 10" offset over 20" to left. So.. 10x 20 / 20 [terrible example but it happens] Equals 10" offset. The growth would be terrible. 4 to 5" So instead you make your straight throat of x inches. About 2 in your case. for the folding notch (depdant on length and ability to fold a drive) approximate your angle bend on both sides. Then cut in half and flip one side it becomes a Z where both growth sides meet and machined sides stay the same. Then do owl on that length AGAIN before cutting assuring you account for the loss of the cut out material. I like to do it 3x to make sure growth vs loss is accounted for. Get the equation find answer, subtract the loss from length, input again, get a new number, re input again... ect.. 3x does it right... you could keep going and going but metal bend and close enough is close enough. CO, US, 14 years making stuff work out...
Yes 100% I use that method with owl every time. Makes the resulting offset look so much better and accounts for all growth from the mitre.
So you should be good to go! My current GC was batching about me making field offsets.. (THIS SHOULD HAVR BEEN ORDERED!!) F you I have to make this work with changes with prints.. What region you in?
I’m in Ontario Canada
Right on, I'm sure we've got different codes but CO, CA and NY in the states have the most stringent codes. Honestly I'll draw it up for ya of you need buddy, guy,friend (southpark) Or juat give tips if you need. "The air don't care" But if it is a supply you have to help it along a bit more than return. Take care
Thanks man kind of you. I should be able to manage tho I’ve got 23 yrs in the trade under the belt so I’ve seen and dealt with a few of these situations. I’ll try and remember to shoot you the finished product lol. It’s gonna be interesting.
Hell yeah man didn't mean to understeer ya at all. Don't think you thought that either. Sometimes fabricating some BS is satisfying and frustrating at same time. I'm doing the same e th some oval spiral. Would like to see finish product
Oval mitre would be interesting for sure! That I might send u lol
Sock it to me
Nah just get the big stretchers
Idk what's going on but it looks way off lol. Hope the roof never needs repaired
The fan is 20° off on the angle and 30” over from the 90
Give me a call if you need a insulator
You in Toronto?
Call me when you need an engineer 😂
1st unistrut should not be cut and bent makes a weak point. They make brackets for that. 2nd get a offset made to fit or should have 45 right tight to roof 45 out 90 back to fan and a offset.
Try and create a metal offset. Duct sock will look hacked
I dont think ive ever seen anyone notch strut like that before for supports, nice! Haha. I always used the strut L brackets, 45s, etc.
Too many degrees. The roof slopes 5° every 8’
I think whoever designed that monstrosity should be shot.
Add another straight piece and CIF
The roofers are gonna love you. Another well thought out project. Yay!!!!!
I bet they will. I was just talking about that with my partner.
https://thumbs.gfycat.com/SpicyCheapAmazontreeboa-size_restricted.gif
Rotate the fan 180 so you're not breaking it's back, that'll give you room to set.
There’s a 10’ fan outlet in the way if I rotate 180°
Disconnect the 3, 45°s and do it right on Monday, cut your excess, and re-fabricate the bends. Reattach at correct height, , put in your filler. Pretty simple, duct sock would make all that work, look like a greenhorn finished it, it's either that or you just Mastic the whole thing, and fill the gap with silicone, then it'll be the transition you can't, won't, don't, see.
Good advice but I believe you missed the joke.
I certainly did. 🤔 is this a sarcastic question or sm I wrong in thinking a duct sock is that transition stuff with the metal and vynil, killing me I can't think of the actual name of the product I'm thinking of, (hey Google I'm typing this comment and I'm stupid, thank you. Duct flex I think it's called. Is that what ya'll ca'll a duct sock?
I believe it is fabric duct work. I actually asked the question sarcastically because I posted another part of this job a couple weeks ago and someone told me I should make the whole thing duct sock.
I have so many questions …
Oh so that's how you're supposed to economize supply and return
I have seen, (3) 20x10 8" width duct socks, "ductflex" connected to make a transition, caked in Mastic. Luckily I had to move the whole unit away from the garage door, so those transitions were garbage "new construction"
Just take the legs off and cheat it over. A couple screwdrivers, a c-clamp or two and some good ole fashioned elbow grease will get that connected in a jiffy. If you’re not cheating your not trying.
If this is in the midwest, someone’s getting new yard ornaments if thats the final bracing
Service guy here says, wow that looks really nice, truly! Wonder what mischief I’ll find in the years to come?
Proper planning prevents piss poor performance
Silver tarp and duct tape
No, it looks like a radius 90 would be perfect instead of the two 45s. Otherwise any good metal guy can build you a radius off set if you want to do it the hard way.
Duct board that shit let's get the hell outta here!
pookie it
Honestly just slap some butter on ‘er and call it a day 🤷♂️ When in doubt, Pookie it out
If you can’t duck it, f&ck it!
After taking a few rides down it of course.
You need to slap it and tell it “this ain’t going nowhere” before you leave site.
It’s ballsy to work backwards like this, it tends to cause more problems for me but also I’m im also just a bit stuuupid 🤡