How to insulate Metal Ductwork with foil insulation - for HVAC installers

If you have been doing this successfully in a more efficient way with better results, please let me know in the comments. Let's make this resource useful to others and make their work easier!

[@peterjacobs9078]

I started w foil bubble w/o spacer, glad I saw your vid. now using spacers - quality work takes time. Would like to see how you do the elbows. Great job thank you!!

[@cleanairheatingcooling4105]

I have a video here on how I do the elbows.

[@cleanairheatingcooling4105]

How to insulate ductwork around elbows. kzbin.info/www/bejne/gqHWaGiIbKyXY7ssi=atWwrBzWBOwKPLBP

[@grambeege]

So glad I watched. I didn't realize you needed special tape or about the spacers. Thanks for this video!

[@grambeege]

I have square ducts. Would all of this apply to square too?

[@cleanairheatingcooling4105]

@@grambeege Yes. The same principal applies to square ducts! We actually installed this type of insulation in rectangular ducting and the processes the same. In this video I was just on a job with round ductwork so I use the example that was in front of me.

[@patrickobrien8851]

Thanks for the useful info, and the clear presentation. The unintended error was most helpful in showing what can go wrong, and how to remedy the wrong. Keep up the good work.

[@cleanairheatingcooling4105]

Thank you for your encouragement! It's motivating to see when people appreciate the content. I will surely upload more! 🙏😀

[@DonTruman]

Great video, thanks. Adding those strips to the duct seems like a good idea regardless local building codes. Cheap and easy insulation bonus.

[@carolinashagman]

Wonder if the spacers have to be purchased separately or does it come with the sheets?

[@DonTruman]

@@carolinashagman probably separate. I expect it's just a difference in the width of the roll, of the same kind of insulating material. The big one being about 4' wide, the "strips" being about 4" wide.

[@toddhare8225]

I work for the company that manufacturers the product that you used.. nice job!

[@cleanairheatingcooling4105]

@@toddhare8225 oh hey that's an interesting introduction! You picked my curiosity. I think there are some comments on this video asking about the specifics of the product. Would you mind sharing what it is?

[@JP-xp4om]

No comment other than to say I appreciate the information that you're sharing, thank you

[@cleanairheatingcooling4105]

🙏

[@brettbarager9101]

I like that you mentioned putting a tab after ripping a piece of tape off. Can't count the number of times I forgot! Lol

[@cleanairheatingcooling4105]

Thank you for understanding the pain of that inconvenience. 👍🏽😁 it’s never fun, gloves, no gloves, long fingernails, short fingernails, in a hurry or not. 😂

[@josephpatrow]

Thanks, very helpful, Sir! I especially value your insights and finer points from your experience working so efficiently.

[@AaronPowellvox]

I like insulating the ducts before I install them folding back at the ends to allow for mastic. Makes the job so much easier and less time consuming. I guess people still like to do it the hard way. Squeegees are free by the way.

[@cleanairheatingcooling4105]

Oh man,.... you're so right. 🤦🏽‍♂️ Honestly in our company we do such a variety of installations from heat pumps to boilers to ductwork and wood stoves that once we develop a process we kind of stick to it if it works for us. But I think what you're saying might be actually even faster especially if we do this on a daily basis. Here's a question for you. If you pre-insulate the 5 ft pieces do you still have to figure out some of your layout while you're assembling the pipes? And if so, do you still have to insulate some of it while you're in the crawl?

[@AaronPowellvox]

@@cleanairheatingcooling4105 I like to plan everything to the tee when I do the installation. At most there might be a small strip needed here or there. I’ve hade plenty of jobs where I’ve had to go in and re-insulate old ductwork. In those cases I do it pretty much just like you did but I squeegee my tape. Lol

[@cleanairheatingcooling4105]

@@AaronPowellvox ok. That makes sense. I will definitely try something like that soon. I might end up liking your way of doing it. If I end up being faster doing it your way I'll have to remember to come here and thank you publicly for helping me 😀

[@tomfromtacomas7249]

Excellent video! Thanks for sharing your method with us

[@cleanairheatingcooling4105]

Haha! You're welcome! 😀👍 Are you guys from Tacoma Wa?

[@tomfromtacomas7249]

@@cleanairheatingcooling4105 Yes, we live in NE Tacoma in the Browns point area

[@cleanairheatingcooling4105]

@@tomfromtacomas7249 nice! 😀👋 Good to talk to someone local on this world wide KZbin. 😀. Tomorrow we have a tech in Tacoma, Fife, Puyallup servicing several clients. Let us know if you want him to stop by.

[@zechariahhambone3841]

Thanks for the vid. I have some free foil bubble wrap that I'd like to use for a 26 gauge dryer duct, one side white the other foil. The duct runs inside the ceiling of the garage which is the floor to living space above. There will be insulation in this cavity below the duct and the rim joists sealed. The garage will be insulated but not heated full time, and 2 of the walls are concrete as it's partially in ground. The heat from the duct would serve the floor well in the winter and help keep the water lines warm too, but, I worry about condensation. If I insulate the duct then I'd lose any benefit of the heat. Once this cavity is closed up I don't ever want to open it up again.

[@cleanairheatingcooling4105]

You're right about what you said. I'd need to know more about what the temps are to be able to answer. But so far you're on the right track.

[@zechariahhambone3841]

@@cleanairheatingcooling4105 I ended up wrapping the duct how you did, using the strips to create an air gap. Really not necessary in my case as it won't be inspected, but it made me feel better. Also used the Dryer- Ell 90 degree elbow and the rugged Dryer Wall Vent which are both awesome products.

[@cleanairheatingcooling4105]

@@zechariahhambone3841 thank you for the update! It makes me happy that this information was useful for you!

[@tunthura9349]

Hello, Excellent video. Thanks for sharing of your method & appreciate it. Could you pls advise brand name and specification of the insulation wrap & tape.

[@phadeon]

Thank you for this video.

[@kyleklakamp8595]

Nice to see a true air gap 👍

[@cleanairheatingcooling4105]

@@kyleklakamp8595 haha. Thank you. You seem to speak from experience.

[@Sean-Aviation]

excellent video! thanks

[@cleanairheatingcooling4105]

Thank you so much! I'm glad you found it.

[@cathyknoop]

Thank you for this!

[@cleanairheatingcooling4105]

My pleasure!

[@toddhare8225]

All insulations work the same way. To achieve R value you have to "trap" an air space. Think of it this way - Let's say that you have a 3" thick piece of fiberglass insulation (duct wrap) rated at an R8 when installed correctly. If you take that same piece of 3" fiberglass and wrap it so tightly that it is reduced to 1" thick it is no longer an R8. Why?? You didn't remove any material right? What you did do was remove the air that is trapped within the fibers of the material. This reduces the R value. Reflectix reflective duct insulation doesn't have any fibers to trap air so you have to build an air space against the duct to raise the R value. The material used in this video is an R4.2 wrapped direct the the duct and an R6 when installed with a spacer. It is a double bubble, double reflective product that acts in three ways. 1. It is an insulation (as explained above.) 2. It is a radiant barrier reflecting back radiant heat at 96% which means that the air in the duct stays cooler in the summer and warmer in the winter. 3. It is a vapor barrier which helps prevent your duct work from sweating. We also offer a big bubble material HVBB48075 that is an R6 applied direct to the duct and an R8 When installed with an air space.

[@cleanairheatingcooling4105]

@@toddhare8225 hey, you know your stuff. You're hired. Thank you for the great explanation! Do you work for the manufacturer or are you an HVAC guy like me? 🧰 👨‍🔧

[@toddhare8225]

@cleanairheatingcooling4105 thanks.. I work for Reflectix, the manufacturer.

[@cleanairheatingcooling4105]

@@toddhare8225 wow. What a connection. Right here on KZbin! Where is this stuff made?

[@toddhare8225]

@@cleanairheatingcooling4105 We are located in a little town north of Indianapolis , In called Markleville

[@cleanairheatingcooling4105]

@@toddhare8225 very cool sir! Sometimes you should send me a text or give me a call so we can talk about this product. It's nice to make connections in the industry.

[@melvingranados388]

Great video!

[@cleanairheatingcooling4105]

Thank you sir! 😃👍

[@kishorchhajed1]

Hi, I have a fiberglass insulation on my duct which is a bit dirty looks a bit ugly ? Can I just put an insulation foil on top of it so that it looks a bit shiny and better ? Also can you let me know the link you bought this insulation Wrap ?

[@cleanairheatingcooling4105]

Yes, you can do what you said. To tell you the truth, typically when you see dust or discoloration on the insulation it means that you're leaking air either in or out of the ductwork and both are not good for the efficiency and air health of your home. If you have the time you should remove the insulation and seal the ductwork so all of the joints are air tight then rewrap with insulation. We purchased this at a local supplier so you can probably find something generic online or maybe home Depot. Or you can talk to a local HVAC contractor if they can sell you some.

[@Inkling777]

Another option is to buy flexible, insulated ductwork, remove the stiffening steel wire, split it along the length, and wrap it around the existing duct. It can be taped in place, but I find cable ties every foot or so are quicker. Choose the correct diameter, and there's no need to measure and cut.

[@cleanairheatingcooling4105]

This is definitely a creative approach and I haven't seen that before I'd be curious how much quicker this is and I'm sure if done correctly the look would be great

[@justinrichard4190]

that would be a waste of money, flex duct isnt that cheap

[@MAGAMAN]

Cable ties compress the insulation reducing the effectiveness of it.

[@cleanairheatingcooling4105]

@@MAGAMAN true. This has to be accounted for during design so with all the airflow issues caused by that the output of the duct is still sufficient for the job. Unfortunately too many jobs have ducts that were just a guess and this leads it discomfort for the occupants.

[@214chopsticks214]

Hey nice video. I have a problem with sweating ducts under my mobile home.. they are aluminum and don’t have any insulation. What kind of insulation do you recommend I wrap it for no condensation?

[@cleanairheatingcooling4105]

You can use the bubble wrap and staple it to the floor with appropriately sized staples. You may also use a 2in R8 insulation. Or even 4in R11 or R13. Up to you.

[@jaredzanelli7867]

Do you have to remove the hanging straps and insulate below them then reinstall?

[@cleanairheatingcooling4105]

@@jaredzanelli7867 you don't have to. If you do so the hanging straps will crash the insulation that's reducing the auto value just below the strap. It's better to insulate around the strap as shown in the video.

[@lourdescotto8603]

Question ....can you do this to dryer vent ducts that go through an attic or does the foil have to be insulated?

[@cleanairheatingcooling4105]

@@lourdescotto8603 you can do it!

[@carolinashagman]

What are the spacers called and do they come with the sheet insulation? Why are the spacers needed?

[@cleanairheatingcooling4105]

@@carolinashagman it’s actually called a spacer. There is another comment here where a viewer who works for the manufacturer gave a really good explanation. He is the expert. 😀

[@benjaminmartin7702]

I thought you use the spacer so the pipes doesn’t sweat.

[@cleanairheatingcooling4105]

@@benjaminmartin7702 that is a secondary benefit.

[@joshsbluecollarbuildsdesig7427]

Could I use this technique for my a/c unit in my attic? My unit in the attic is use for a/c only, we have radiant heat, so they install a a/c unit in the attic with flex duct and it’s the worst most on efficient installation I’ve ever seen! So I’d like to redo the job and make it more efficient. I live in Wisconsin and my attic is a unconditioned attic I think? Lol. It’s a vented roof with ridge vents. I was thinking of doing some type of rigid duck work and wrapping it with insulation, so any tips or better ideas would be greatly appreciate it. Oh and by the way great video. Thanks for any help you can give this way. .

[@cleanairheatingcooling4105]

Of course man. Could you send some love this way and promote our channel 😁 Now to answer your question. Yes you can do exactly what you said. I'm surprised that wasn't required by code or caught by the mechanical inspector. Please comment below with further questions. 👍

[@njsongwriter]

Where can I get that insulation?

[@cleanairheatingcooling4105]

@@njsongwriter HVAC suppliers. If you can't get it we're happy to supply some.

[@almann5798]

How would you wrap duct work that is a square box under my mobile home my duct work is a flext tube from ac to metal box that runs the floor of my home

[@cleanairheatingcooling4105]

@@almann5798 usually that metal rectangular trunk runs the length of your mobile home. You may have one or two of those if it's a double wide. Typically those are already pre-insulated along with a subfloor and the membrane. Is another case for you? If they are exposed you can wrap them exactly the way I showed here. You may also use a different technique where you use a fiberglass insulation and staple the insulation to the subfloor after wrapping the duct so basically forming a u-shape.

[@almann5798]

@cleanairheatingcooling4105 yeah few of my vents are sweating and water is getting into the duct work so i was going to wrap them to see if that helps and see if it helps lower my bill some its a 92 mobile home ive own it for 5 years so do not know how it looks under there

[@cleanairheatingcooling4105]

@@almann5798 does my answer help you at all? If not you're welcome to send me a picture from under the house so I can see the ductwork and I can give you more accurate advice by text.

[@almann5798]

It helped thank you

[@paula7256]

The ducting in my crawl space is wrapped with fiberglass insulation only. I want to wrap the ducting with foil insulation over the top of the fiberglass insulation, is that okay. Thanks.

[@cleanairheatingcooling4105]

Generally speaking, yes! Under normal circumstances I would totally go ahead with that plan!

[@samterracina]

Our camp has ductwork in the space under the camp. The camp is on a slope. Squirrells have ripped the fiberglass to shreds. Would replacing the fiberglass with foil eliminate this problem?

[@CDX825]

Yes it should.

[@cleanairheatingcooling4105]

From my observation having worked in many homes and commercial buildings The fiberglass insulation seems to be attractive to rodents. That doesn't seem to be the case with the bubble foil insulation. I couldn't guarantee it but I expected to be less of a problem if you were to use the foil insulation.

[@Sean-Aviation]

where do i get the same insulation used on this video?

[@cleanairheatingcooling4105]

We get it from a local HVAC supplier. There are so many different kinds. You may be able to get it at home Depot or Lowe's or some other hardware store. Let me know if I can help you further.

[@presto25100]

Thanks for the informative video. Do you use the same product on rectangular main heat runs as well or is there a ridged product for that?

[@presto25100]

Also, what was the width of the product you were using? Lengths also 50 or 100 rolls? Thanks!!

[@cleanairheatingcooling4105]

@@presto25100 thank you for watching. Please like the video and subscribe to strengthen out chanell. Much appreciated! 🧡 Yes, we use this for rectangle and round duct. And the width is 4 ft. I don't recall the length. I'm guessing it's about 100ft. It might be 75 ft.

[@PaulMillerMI]

Thank you!! Liked and subscribed.

[@lifeisbeatiful404]

great video, what is the thin insulation strip you used? I cant seem to find that anywhere?

[@cleanairheatingcooling4105]

The thin strip of insulation comes in the package with a big roll of insulation and is used to create an air gap so the rating goes up from R6 to R8.

[@lifeisbeatiful404]

@cleanairheatingcooling4105 thank you so much for replying so quickly. Can you please share the link or brand of the large insulation roll? TiA 😊

[@cleanairheatingcooling4105]

@@lifeisbeatiful404 I don't know nits a pretty nondescript roll of insulation that comes in a cear plastic bag. If I come across any specifics or brand name next time I work with it I will let you know.

[@justinrichard4190]

you can just cut and make your own strips from the roll

[@cleanairheatingcooling4105]

@@justinrichard4190 true. I use the rolls that come already pre-made for us to save time but yes we could just get strips out of the roll.

[@richardwhitmarsh5702]

What foil product is that?... Reflectix? rFOIL? Other?

[@craigdeluhery2276]

Looks like a metallized film tape. His looks like Flexfix but any 181 UL rated film tape can be used.

[@cleanairheatingcooling4105]

@@craigdeluhery2276 💯 ✅

[@alcapone3481]

Why didn't u insulate befor you hung it ?

[@cleanairheatingcooling4105]

Honest answer? I learned that option after I developed this habit. So currently I like the freedom to run the doctor however I want and I'm just assembling duct and zipping it together. Then I go through with mastic and then I go through with insulation I guess it's just like a three-step process that I learned. I would have to try it your way several times in a row to see if I pick up speed doing it that way. Actually a lot of people in the comments have been suggesting that so I'm taking it very seriously 🫡

[@JimmyWheeler-b6k]

getting from the basement to the attic, do i use rigid steel duct and transition to foil flex insulated duct once i get into the attic space? Or do i go from my air exchanger right to the attic with foil insulated duct? Thanks!

[@cleanairheatingcooling4105]

You have to use rigid duct to pass through the floors. Anything enclosed must be had pipe. Attic and crawl are the only places where you can use flex. Can you clarify your second option? IDK if it was a typo

[@NagaPope]

Why do you use the slim strips of insulation before the large strip? Can you just use the large insulation to insulate?

[@danielleSolomo]

He explained @3:15 why

[@cleanairheatingcooling4105]

Great question! Currently in the state of Washington ducts have to be encapsulated in condition space. Prior to this code, ductwork had to be insulated to the R8 value to meet energy code. The bubble insulation in most cases is either r4 or R6. When you add the strips of insulation and the air gap it creates, it's rated at R8.

[@roysimpson2126]

Were you not listening?

[@joshuaseaton4526]

Or just buy the R8 bubble wrap. You will save on labor. That strip cutting is a joke and whoever invented that needs to go pound sand.

[@American-BadAss732]

I just double wrap the smaller bubble insulation because the R8 has bigger bubbles and when it pops there goes the r value..and id jus use foil tape .that shit he's using is used for line sets I thought

[@joshuaseaton4526]

@@American-BadAss732 Better yet, double wrap with the R8 and you get about R12 with it. Spendier though of course.

[@pattognozzi]

That is actually the correct you install R8 bubble wrap. The sheet is two layers of bubble with strips in the middle to create an internal space. Before you put that on the duct you have to apply the spacer strips of 2” wide bubble wrap. If you put the sheet directly on the duct without the spacers you will only have R6.

[@frankgiovannetti3077]

If you What do you think of foam spraying the ducts?

[@cleanairheatingcooling4105]

I've seen it done. I don't have a strong opinion one way or the other. The benefit of spray forming the ducts is they get insulated and with closed cell from insulation it's also going to be airtight. The drawback would be if you need to do a repair or anything has to be modified the foam will add an extra level of complexity in dealing with the ductwork. So there are pros and cons to it. I would love for spray foam professionals to share their opinion on this.

[@cleanairheatingcooling4105]

kzbin.infofS84nRaBSJA?feature=share

[@cleanairheatingcooling4105]

The link above is for an example of ductwork encapsulated in spray foam

[@nzfalcon6578]

way easier to insulate ducting before installing it

[@cleanairheatingcooling4105]

True. We've done this on some jobs. Do you mind sharing if you always do this or are there certain scenarios where you just want to get the duct installed and route it the way you want and then going back to insulate? The reason I'm asking is there are times when even if you pre-insulate the straight pieces you still have to go back and insulate smaller pieces that you have to cut on the spot or elbows. I'd love to get your input on that.

[@bholtslander]

I'm watching this video because I live in a house that is almost 40 years old and it has all metal ductwork. the insulation is falling off in spots so I was going to reinsulate it. Point being, it is obviously already installed so this video benefits people like me. Not everyone is installing new ducts.

[@cleanairheatingcooling4105]

@@bholtslander absolutely! I'm glad this is useful for your situation. Maintention in the video is not to come across as if this advice only applies to new ductwork. The concept applies across the board. Hopefully your job goes smoothly reinsulating your ductwork.

[@tma-1704]

Can this procedure be applied to metal duct work or is there a better method for metal? Thank you.

[@cleanairheatingcooling4105]

Yes. This is shown on metal ductwork. This is the most efficient method for us. There are other ways to do it. Different materials, different methods.

[@HARVIELL1]

These guys use more gloves than a proctologist......

[@cleanairheatingcooling4105]

😂