Cutting takeoffs and proper attachment to trunklines (Mechanical Training # 104)

[@Tony-dk1bp]

I can't imagine a better teacher.

[@yodamanrulz176]

I have to applaud the teaching capacity, patience, and forthright giving the knowledge that this fellow is capable of. Your methodology should be taught to other teachers. So many are flawed. Thank you for your time sir. You’re one in 1 million. 👍🏻🤓

[@courtneywilliams9530]

I teach for a living and he is a natural born teacher. His companies website says they have 100 years of experience, so I’m guessing he came from a family of excellent teachers. But I’m sending this to a number of my HVAC oversight on projects I’ve volunteered for because it is so helpful. Please keep putting out more. I will watch them all!!!

[@Mr572u]

⁠@@courtneywilliams9530. Company’s

[@RealGame101]

Yeah he's good

[@Infowarrior-1776]

Just finished this one. Your attention to detail and quality is phenomenal. Definitely inspires me, as I am in my last trimester of HVAC school, to step my game up! Thanks again for the lesson!

[@RVCrazy]

Thank you for recommending and making this video. I know with your instruction that I’ll be able to do a better job than most anybody I’d hire. Thank you.

[@alexeilesukov6624]

My baby brother just recently got promoted to foreman at a hvac company and wants to bring me in. He told me to try to learn as much as possible about the trade by watching KZbin videos. He said that your videos are the most informative ones and that I should follow and subscribe. He also told me to lose some body weight. When you mentioned working in crawling spaces and uncomfortable positions, I understood. Thank you

[@erichorton1440]

Highly recommend starting your own hvac company. You'll make millions.

[@FcsstlHeatingCoolingPlumbing]

I use zip tie and 3 zip screws into the band of the zip ties.

[@markmartin6856]

You can always tell when you're being taught by someone with tons of experience. Great job dude!

[@derekw40]

This guy did a great presentation. Tons of real information very little filler. Thank you sir.

[@WOW_AQUATICS]

Best video on professional instruction installation I have ever seen. Thanks sir.

[@tantricsphinx]

When this piece ended, I thought, "Wow! That was the best..." 🫡

[@lmoore5264]

What a great video Andrew. I can't believe how much I learned in 36 minutes. You didn't stand there and babble for 10 minutes, you got straight to the point. In my book you are the definition of the word PRO. I wish we had more you tube creators like you. You didn't waste my time and I learned a lot. Thank you!

[@199randomhero]

This is hands down the best video I've seen for someone new to hvac and explaining how to do these connections and cutting, thanks!

[@patrickjoseph7726]

Andrew, that was fantastic ! I'm a professional handyman and this is probably the best video I've ever seen for conciseness, camera quality, knowledge, and voice presentation . Great job ! PJ

[@douglassmorris7375]

I'm a DIYer and started a register reposition out of frustration. Was really uncomfortable until I watched this video. I am now so ready to finish this job😀.

[@TAYLORD_Technologies]

I have to say... this is the first video I've seen of this guy and AGL Mechanical. This is hands down one of the best teachers I've seen on KZbin. A lot of relevant information and little simple tricks of the trade. 10/10

[@jamespurchase4035]

Jack Reacher does HVAC too? I'm impressed😂

[@76TomD]

My 1st thought as well.

[@ericviele4379]

Mine too! 😂

[@LokiandBjorn]

🤣

[@freddycarballo4248]

Man you are professional with no doubts.

[@pin_cushion]

Please keep making content! These videos put This Old House to shame. I just paid for a system design for my house with no preexisting duct and I'll be DIYing and this is the best advice for ducting i've stumbled across.

[@tantricsphinx]

Andrew, I wasnt familiar with your channel before watching this video. Just wanted to say that I love your communication style. So deliberate, detailed, well reasoned...no fluff all useful knowledge. That was 36 minutes of learning. A very satisfying experience. Thank you!

[@NotSoSmart32]

Took on the job of installing my own furnace/heat duct. Lots to learn, thx for all the in depth info!

[@JohnBehling-ek6ik]

Outstanding video- you are an excellent teacher. Thank you for taking the time to share some of your knowledge.

[@danurdahl4420]

I really enjoy these videos and he explains what he is doing so well.

[@JayMurrr]

I watched many videos and got bored AF. But for some reason yours got my attention and I watched the whole video. I’m trying to add a run to my garage so I’m sure this is what I need to learn.

[@ianhinkle4587]

2 years as an apprentice summed up in a 36 minute video. Great work. Keep them coming.

[@mikev.1034]

I seen a bunch of videos like this but, I think your method is definitely superior to other methods I seen. 👍

[@3dux128]

Pro! Pride in workmanship! Whatam I doing here. He had me hooked. Thanks.

[@colindgrant]

Fantastic video. Very well explained with no fluff.

[@jeremygattenby2183]

Thank you! Going to be installing my own ducting to save some money. This video really helps.

[@ebbiebob]

Man you make amazing videos! Thank you so much! I really appreciate the education! Bless you! 💪🙏💯💯

[@jdawes4403]

Keep ‘‘em coming bro- you’re helping people !

[@scottschweigert1657]

you gotta add a tip jar or something to your links --- this is such well done and high quality content

[@israelquintanilla2784]

Thank you for taking the time to teach us this very much appreciated

[@michaelohara2161]

I’m a Sheetmetal Local 80 commercial journeyman retiree. I carried that tool for years. I used it off and on. I never liked it much, because of the metal shavings everywhere. I always had my hammer, flat screwdriver and midwest aviation snips. Those flange taps are relatively new. Spin on and tab taps, and conicals, were way more common. Although I do like them.

[@absoluteidaho3767]

Excellent video and information! Thanks for sharing your knowledge!

[@ryansport33]

I'm hooked. OG methods shown here!

[@gabrielakerekes5844]

Amazing video,very clear and at point teaching. Love your video and too bad you are not servicing Florida. We need to connect almost all returns from rooms to the main line. Builder did run the flex tubs but didn’t connect them to the Trunkline and that cause us a great trouble with AC uneven in rooms having 6-7 degrees difference from main hallway in the middle of the house where the main return it’s hook up and the rooms around the hallway. Now after leaving 10 years in the house we discover the returns are not hookup to the trunkline. I would love to give you the job but you are in different state. But honestly your video couldn’t be more clear and having mechanical knowledge and education,I think we my husband we can do it. Thank you for your video and I already subscribed . I enjoy watching you valuable classes! 🥂

[@marcveuhoff1871]

Excellent Video! We'll explained. I've seen many duct tutorials and you are one of the best.

[@philiplacey5430]

God help me if I ever need to crawl up in an attic and do any of this - but if I do, I'm ready! Nicely done!

[@shellylynn899]

It's horrible in the dead of summer with this crazy humidity

[@monkeyfinger7949]

Really great tutorial. I learned a lot. Thank you!

[@RealGame101]

This video was so good thanks man. All I need to do now is figure out where to reduce the lines

[@Esiddik]

I watched like toooooo many videos of nonsense before I found you!!! and the only problem was because your title makes your videos hard to find !!!! 😭😭😭 ( for a beginner not knowing those are the terms to use) Amazing tutorial , you are an amazing teacher!! I wish I found you 16 videos ago 👏🏼👏🏼👏🏼👏🏼

[@gordonbramhan7520]

I have been in hvac for 30 years but installing ductwork is not my thing. Thanks for the information and detailed explanation I use zip ties and duct aluminum tape exclusively

[@thomasbessent3670]

sir I want to thank you for an outstanding presentation ! you have saved me thousands of dollars , you are very practical in your profession you have one good gift , and this one is needed in the HVAC community as a homeowner I will take out my 30-year-old duck board that has invaded my home . again thank you so much for your presentation ): God bless you and your family .

[@matthewray4637]

From a fluid mechanics point of view, adjacent takeoffs (or takeoffs on opposite sides of the trunk in the same area) are more efficient than having two side by side on the same side of the trunk (particularly when they are close together). Adjacent ones will evenly distribute the airflow to both takeoffs and create two opposing vortices in the trunk which creates a negative pressure in front of takeoffs leading to a forward turbulent flow in the trunk line which has better sheer properties and can actually improve performance over longer runs. Having them on the same side one after another will create two vortices with the same direction on the same side, this can cause two big issues. First, if they are too close, you will have flow separation and potentially flow reversal immediately after the second takeoff. Second, if they are too close the vortex around the first takeoff can create a turbulent flow over the outlet to the second one creating a drop in pressure in the second line.

[@tomhernandez1308]

I thought your cutting method for a takeoff hole was quite novel and effective. Given then chance, I'm gonna try that myself in my own DIY work. Thanks for the very helpful video.

[@Davidandgoliathhvac]

Great content Andrew! Keep showcasing your craftsmanship! It inspires guys like me to improve our skill set and quality of work.

[@yorkrojas1452]

Thank you Sir. Just started in the Trade!! Thanks a Million!!

[@terrygrant8126]

I have done it wrong and now I know thanks to you friend!

[@edwardsmith9256]

thank you for your excellent lesson on Flex duct work. I am currently replacing my old flex duct. I now see what I could have done better. Thank goodness, I have only just started. Hopefully, the fold back method will make things much easier. Thanks again for your video.

[@clemgray]

Thanks… You just saved me $4000. Awesome

[@briancarroll.]

Great video. Thanks for the lesson!

[@jerryc7016]

Excellent video. Very detailed. Easy to understand. 👍

[@annemoreno362]

I've looked everywhere for an adapter that would take and go from the register into the trunk line on both sides and continue down and across the transfer duct kind of a wonky T. They are nowhere to be found. I applaud you making your own

[@Lkom24]

I love the malco hole cutter

[@carlotodaro5052]

awesome lesson, I can't wait to see the workmanship I have in my attic. I'm going to finish a room upstairs and wanted to see how everything needs to be. That was a great how to and explanation on how it all works. thank you, Sir.

[@ArnettEducation]

man, thanks a lot for this! very helpful!

[@JackA2430]

Great video man

[@jamescollins8148]

Phenomenal! Great video Thank You Andy!

[@jamescollins8148]

Andrew sorry

[@tunaman2200]

Excellent Video! Thank you!

[@JonathanCamargo-q7c]

excellent explanation

[@The_Honcho]

Great way to connect flex, this is how I do it now, even had my boss try to pull the flex off lol

[@janerikborge]

Excellent presentation. Thank you.

[@markdarling7526]

Just watched all 36 minutes and loved it. You have taught me a lot about running and installing ductwork. Am about to tackle my house here in Florida. Original ductwork is 39 years old and I’m losing air and house stays dusty all the time. My house is only 1200 sq ft and replaced my unit from 1 1/2 ton to 2 1/2 ton just 10 months ago. The original ductwork is all flex , main truck line is 10” with 4” going to all the registers. Any tips or advice or other of your videos of yours you can tell me. Thanks again for taking the time to share your knowledge in this matter of HVAC ductwork.

[@Perly53]

Hi Mark. I'm in FL too with similar situation. Did you get this done? How did it go?

[@wdanderson1984]

Great information dude. Thanks for the video!

[@ansarhassan4]

Great video loved it, just wondering how to choose right duct size, I am planning DIY duct for my parents house. Please have video on this subject

[@kelturner5452]

When we do takeoff on insulated trunks we use the end of starter to cut thru by rotating back& fourth,like when you demonstrated dropping marker. Fantastic tutitor glad I' ve found your channel,subbed 1st. video before done. Great content no nonsense instructions! Keep them coming,love phrase quality is your reputation!! Permission to borrow sir? Thank you

[@aglmechanicaltips]

You can use that phrase all you want. I'm glad you like the channel.

[@Charlieman.]

really superb thank you.

[@aKumah.]

deserves a subscription 🤝🏼💪🏼

[@josesquiabro5819]

Great video

[@andranika6203]

Thank you for teaching 👍👍👍

[@WhiteWakedNProud]

TWIMC here in socal in commercial for flex tails, we use panduits with a strap gun and some people sink 3-4 screws into the zip tie. After using the strap tool, I've never had one snap or fall off with or without screws. As long as the strapping tool was used on a fitting with a rib, without a rib it'll forsure pull off but get it tight with the strap gun and fasten some screws through the zip ties, like 3 or 4 minimum even spaced out, then call it good. And the use of tape is unnecessary and air leakage will be minimal which imo makes the process easier, quicker, and prevents frustrations from working with tape. I'd also like to add that i think people snap the zip ties using the strapping tool and snap the zip ties which leads to frustration, causing them to hand tighten them or use linesman. Which is easily pulled off, however some screws into the zip ties can help without the strapping gun. However I believe this is due to mishandling of materials. If film tape, zip ties, or even the pookie get left in the sun it can degrade such materials significantly. Thank you showing how to insulate fittings, i spent hours google searching how to and such info was not available. Cant wait to wrap a 90 and it look tits

[@carloschacon3909]

Thanks for your video...

[@jimmyfavereau]

Gold! Thank you 🙏🏼

[@damianbenavides8653]

Thanks 👍🏻👍🏻

[@pastormartinez4676]

Branching is the best best method, it self-balances air pressure and velocity.gradually reduce the size from the plenum with wyes and always use angled take-off’s (unless you’re working on a tight area such as a basement) Also,make sure to use dedicated Panduit gun (semi or automatic) and keep duct stretched and turns smooth! As a side note,we always use manual adjustable dampers, (where access is possible) it pays off when customers call-back complaining about un-even airflow (trust me,they always find a problem in one of the rooms)! And last but not least… if you’re running over 25 feet duct,upsize diameter 2” for friction,remember air is a fluid and follows the rule of “Path of least resistance”! I keep learning and improving my methods every day and following others good practices I’ve seen when I get a chance(on service calls) and applying what I’ve learned over the years… I must say without bragging that the results are extremely satisfying! This video it’s a good introduction for the apprentice on “How to” do the work,but in practice wouldn’t perform at it’s best! Good enough it’s neither good nor enough! Don’t get me wrong,this is a good video,but it would be a great video if it further explained the above mentioned facts!

[@TonyNanni]

Why don’t you explain what your “branching” method is and show these “angled” takeoffs you would use on round pipe trunk line.

[@lawlissmml1]

Elon should hire Andrew to work at Space X. The prior comments nail it - he is an enigma. A rockstar instructor!

[@ericviele4379]

Fantastic teaching and incredible work. My only concern was that you kept mentioning duct tape, but I’ve always heard duct tape is no good in this application (oddly enough). What type of tape do you use?

[@rod00777]

What type of tape is he using?

[@gen-shynobi7939]

I just subscribed thanks for you r videos btw do you have a start to finish set of videos I /we can watch i want to install my own lines to my home im remodeling and this home 1950s didnt come with hvacand id like to install one im in need of this info asap thanks

[@nlh8162]

Well that's a great teaching sermon right there my friend the problem is you have to find the suppliers that will stock these parts I love those start collars not all suppliers have them

[@salzafar2030]

Great video, is this some special duct tape for hvac ducts? Thanks

[@aglmechanicaltips]

Yes, the tools and materials used are linked in the video description

[@scotthayes6946]

Hi Andrew. Great video. Great tips. Great techniques. One question: What is the duct tape you are using? Many thanks.

[@aglmechanicaltips]

In this video I used Nashua 365 a.co/d/fAO8lsM This is a really sticky tape though so if it is really hot out 90°+, you might want to use shurtape (I dont have the model at this time).

[@scotthayes6946]

@@aglmechanicaltips Wow.!! Thank you for the speedy reply. I will give the Nashua 365 a try. Many thanks.!!

[@thecurious6721]

Thanks for the great tips 👍 I am in Canada and we use rigid uninsulated ducts, which are (mostly) in conditioned space. But it is very informative especially as the flex ducts (as the manufacturers say) are gaining popularity here as well. Could you advise what kind of duct tape you are using and what will happen if you dont mastic over the tape at the take off? Do you use flexducts for 2 storey houses as well? We have difficulty moving air from the basement to the second floor with rigid ducts. I am wondering how it would be with the flexducts. Thanks 🙏

[@aglmechanicaltips]

I was using Nashua 365 duct tape but I will changeout the tape used based on the season and outdoor temperature (super sticky duct tape is hard to work with on hot days). Mastic provides air sealing when applied directly to sheet metal seams. When applying mastic over duct tape on insulation seams it just provides another level of durability to the tape and prevents the tape from coming up. If you didn't mastic it, it would probably be alright but if it's available I would apply it. Couple notes on flex ducts; In my region, we don't have basements and normally wouldn't "chase" duct up to another level due to the length of run and a couple other factors. Long lengths like that should probably be ran in hard pipe but flex can be used if you do a static loss calculation on the flex and upside the flex to a larger size to account for the static loss. Example: a 6" hard duct that is 20' long might be equivalent to a 8" flex duct that is 20' long (I didn't calculate this, I'm just giving you an example). Hope this helps.

[@thecurious6721]

@@aglmechanicaltips Thank you very much for such detailed answer. 🙏

[@hairlesscactus]

Do you ever have condensation forming on the uninsulated ducts?

[@thecurious6721]

@@hairlesscactus in normal situation - no. In my experience I had issue only once, when the guy closed basement registers and it was very humid there and airflow was slow, so that ducts where very cold. Sometimes plenums sweat a little bit. Other than that no issues. And we have 70% humidity in the summer.

[@hairlesscactus]

@@thecurious6721 thank you for the reply!!

[@jonc5152]

man - wish I'd found this sooner... I am on the tail end of redoing my upstairs (attic) ductwork. Not knowing how to handle rigid duct I opted to just do everything with flex. I basically made 2 straight headers down each side of the attic and tapped off to boots using wyes. I screwed the flex wire to the wyes with zip screws and sealed with mastic tape.... the inside air seals are durable but the jacket seals are not super great. I used canned foam to foam insulate the wyes but it makes the connection to the flex insulation odd. I think my way out to a decent quality is duct tape between the vapor barriers and foam. I am also considering zapping them with a coating of spray foam (2 part, not 1 part cans) as additional exterior sealant. If the duct taping goes well then I may just be able to mastic the whole joint instead. I leaned a lot on the attempt and I've also learned a lot from your great channel. If I redo my ducts in the future (if the ones I just did have an issue or maybe when I go to change out my new HVAC units in 12-15 years) then I will definitely go with rigid metal headers, hopefully I can just find pre-insulated spiral sections... I don't understand why those aren't more of a "thing".... pre insulated spiral with an array of pre insulated fittings... suspend, screw, foam seal together. Anyway... thanks Andrew!

[@johnkruesi9817]

Can you take offs like this on 8” round duct? Great video btw

[@aglmechanicaltips]

Yes they do work on 8"

[@Ageehvac]

Thanks bro...lots of info

[@davejohnsonnola1536]

F&B refrigeration guy looking to upgrade my 1940s cottage to central HVAC. Gracias.

[@elonmust7470]

Thanks for putting your heart into what you do. I appreciate your sharing of knowledge!

[@willowmoon4866]

Can you teach us to connect a downdraft for an evaporative unit 3000 c.f.I . House 2:29 is 40 length x 35. It has three room left house plus 10x10 bathroom and right side living ding and kitchen. Do we use aluminum duct work or that flex stuff. Please teach us. Need your advise

[@johndavidson5564]

Ok liked and subscribed first of all, second, I'm a commercial HVAC lead in Indiana and I have never seen anyone duct sealing the outside of insulation. Is that required in your area? we also never use the yellow formaldehyde insulation usually r-4 1/2 inch formaldehyde free, the white kind. Unfortunately, Panduit straps are commonplace here but I also tape the inner flex and then the outer after Panduits. Though after hearing your tear out experience with sweating I may stop panduit strapping the outer jacket. I am very curious to get your thoughts on some things as I am always trying to grow and learn. We typically wrap out pipes before installation, and then double back and duct seal all metal seems, then the next day we come through and piece out the missing insulation. We do not use staples as a matter of fact I have never seen staples be used here. Almost everyone uses Nashua FSK tape for holding the insulation together and some companies only use 3M Venture Tape UL181 which both does not adhere very well, and looks bad so I try not to ever use it. Also wanted to give you some video ideas since it seems that the channel is new. I would love to see you wrap a reducer and an end cap and some other fittings. thanks.

[@stephenzavatski8016]

Yeah, I actually need to see a reducer wrapped as well

[@jorgenorman8715]

I wonder if you can use mastic tape all around a magic boot or the straight boot instead of wet mastic

[@aglmechanicaltips]

Mastic tape is only good for metal to metal connections but it works awesome when it is stuck to metal...

[@ProfessorGilligan1]

I have flex duct that has disconnected from the main trunk in my crawl space. So, this is not clean, new vapor barrier. How do I get the old flex duct to attach back to the old and dirty take off and main trunk vapor barrier without just releasing? BTW, no mastic was used by the professional HVAC company. I’m wondering if I mastic over the properly attached vapor barrier release can be avoided.

[@cadamham]

How do you see taps with dampers and adjustable handle?

[@xmanprime3328]

Safety glasses???

[@RichardKirts-x7g]

1 thing I do is I put3 screws in the flex behind the wire spiral . That way it holds it tight. Rich.

[@TheFla904]

Pookie on the inner liner first, then panduit strap on the inner liner

[@themrmoy40]

why pookie the inside ?What's the point on that?

[@MFD541]

point is, no excuses for not knowing your job. well done.

[@devinfisher1815]

Is that tape 1402 mastic or something a little thinner? And I assume it’s not necessary to mastic over the take-off to supply line? Thanks for the info.

[@aglmechanicaltips]

It is 1402 mastic tape. If using "mastic tape" then it is not necessary to mastic over the takeoff but it should be sealed one way or the other if in non-conditioned space.

[@devinfisher1815]

@@aglmechanicaltips Ty!

[@TB-px6jk]

Do I need to paint the tape seams with duct seal on the supply and return ducts in a crawlspace if the crawlspace is encapsulated and has a dehumidifier installed?

[@aglmechanicaltips]

Yes, unless the space the duct is in is the space you are conditioning I would seal it as much as possible. Any leakage into the crawlspace is lost efficiency. I use a product called "mastic tape" on my ductwork seams instead of duct tape then mastic (just saves time). I also seal the exterior seems but that is a code that exists in my region and might not apply to you.

[@darrenaugustine6508]

Thats awesome! What is your method of insulating boots?

[@aglmechanicaltips]

We have been working on a video on insulating misc fittings which includes straight boots, 90 degree boots and endshot boots. We are hoping to get this video uploaded this week. Stay tuned!

[@BloominOnion1]

Hey man. At 30:00 let's say I have a damper in that collar with a threaded rod and wingnut sticking out. What 's the best way to get that flex over that without rips, etc?

[@aglmechanicaltips]

I understand the struggle here. I bend the damper handle out 90° from the takeoff. Make a VERY small slit in the insulation jacket and press the handle through the insulation and insulation jacket. I then stab through a piece of duct tape with the handle to prevent the slit I made in the insulation jacket from spreading. I then bend the handle back down. So in the end you have a clean piece of duct tape flat against the insulation with the handle sticking though it. I hope I explained this right, kind of difficult... Also, depending on the flex brand you might not have to make the slit and can actually pierce it with the damper handle itself.

[@BloominOnion1]

@@aglmechanicaltips you are the man. Thanks for the info. Top notch channel.

[@performancehvacr6629]

I have always done at least two wraps of duct tape and 3 screws. Do you find a need for screws? Awesome videos. I watched the first one a while back. Glad to see you back at it.

[@pete7960]

Your knowledge is amazing/impressive! I am working on a small 2 bedroom 1 bath home 880sq ft. The plan is to install a 2 ton unit with a square to round plenum that will include a 12" trunk 5-6' long. The trunk will have 6 takeoff saddles, (2) 8" for kitchen/dining and living room. (2) 7" for the 2 bedrooms and (2) 5" for the utility room and bathroom. From trunk to register boots there will be flex duct used 3' to 6' long max. I am wondering if this will provide sufficient air flow? The ducts will be in the unconditioned space with the intention of producing a compact system. Attic space is limited, the highest point is 24" Any advice will be greatly appreciated.

[@aglmechanicaltips]

Without me going to paper with what you outlined I believe this will work fine. I would run a 14" return minimum to lower the system static pressure but 12" supply should be fine.

[@pete7960]

@@aglmechanicaltips Thanks Andrew! I watch your videos over and over, you have made it soo much easier for me to insulate. I hope you were in south florida, I would hire you, down here quality and workman ship is soo poor. Its all duct board and flex. I am looking for a quality install that I can only achieve by doing it myself.

[@pete7960]

@@aglmechanicaltips After writing my question. I have decided to make it mostly sheet metal, except for the area that the ducts cross the attic opening, there I will run short piece of flex, so if I ever need to go in the attic, I can remove the flex for easy access.

[@pete7960]

@@aglmechanicaltips I am installing a 9" jump duct from room to room and in the bedroom I am placing a 14x14 return grille on the wall where the air handler is on the other side. For the rest of the house, I will be using a louvered door.

[@aglmechanicaltips]

Return will work great like that. Is there a reason you are using hard pipe for the branch lines? Sheet metal is technically better durability wise but if flex is strapped properly there is absolutely nothing wrong with it and your system will be much quieter at the vents as flex does much better acoustically. So hard pipe or flex but if it was my house I would flex those runs all day long especially with how short they are...

[@ludwig6332]

The guides state it is better to have opposite take offs at the same place for efficiency, as staggered close together reduces aire flow, static pressure.