HVAC EXPERT Shares 5 Tips on DUCT Insulation!

Homeowners give a lot of thought to the efficiency of their HVAC system but very little to ductwork or the insulation. In this video, Joshua shares 5 tips on ductwork insulation that may help you make a decision when the insulation starts to have issues and how to come up with a solution. Choosing the right duct insulation and having it installed properly could make a huge difference on utility bills and overall performance of your HVAC.

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-----------Chapters-------------
0:00 Intro: HVAC Expert Share 5 Tips on Duct Insulation
0:16 Does it make sense to reinsulate the ductwork?
2:00 Different R values on insulation
3:00 Conditioning the area ducts are located
4:39 Can you do this?
5:55 New Ductwork insulation technology
6:40 Future of Duct insulation

#hvac #hvactips #ductwork

[BESTFORYOU]

With prices of HVAC Professionals nowadays, DIY is a necessity!

[marlonsly]

Great video. I love your straightforward explanation. I live in south Florida and I feel like my AC unit is struggling to keep up. I’ve had one company tell me that my AC handler (installed in 2019) needs to be replaced. While another company told me it was fine. They recommended adding more air flow pass through for each room. But as you mentioned in this video, my attic is a hot box. None of the contractors I brought to my home have suggested examining my ductwork and or insulation.

[scubajim]

Good video. I'm working on air sealing and reinsulating the ducts in my 80's home. The upstairs air handler/furnace (original to the home) is in the attic and it struggles to keep the upstairs at a liveable temperature. I mean 89* F while on full blast in the summer on a hot day. My HVAC company just said "it is what it is" and "your A/C is running fine." In the process of reinsulating the existing ducts (round metal), I've found tons of air leaks, which I think is probably my main problem. Some vent boots had inch+ gaps around them. There was an inch gap along the bottom of the supply plenum where it met the air handler. No mastic sealant was used on the ductwork. Most of the old fiberglass was brown from dust sucking through the air gaps. Huge amounts of cool air have been blowing out into the attic, hot dusty air coming into the system, and cool air from inside escaping via the attic. I don't want to spend a fortune on a contractor, so I'm doing bit by bit over my weekends (trying to get it done before summer!). Just my luck, the system will go out in a month and I'll have to get it all replaced anyway 😆 But the R8 foam insulation I'm using and the mastic paint have been a pretty small investment (around $250), so I'm not too worried about it. At this point, it's more about liveability and air quality than just pure energy savings, which I'm hoping to see but not betting on being all that significant.

[MrSki-tyvm]

Yes, I got hit by trees from Helena that caused roof, shingle and branches punched through my duct and ceiling. The insulation on duct was original from 1964 on ridged ductwork. My solution was simple because I did it myself. Flex duct comes in 25 foot lengths which is much cheaper and faster because removing the inside duct gives you a perfect insulation sock to just slide on to the ridged pipe. It's easy to stripped off old insulation used a grill scrubber to clean exterior, disconnected lines to the main trunk. Then I brought flex duct and pulled the inside flex duct out using the rest as a sock that I could cut into good lengths. I simply, cleaned all joints, retaped and brushed on mastic over the tape to make sure it would never peel. Let it dry and slid on the insulation sock, cut out the holes where branch lines attached, screwed, tape, and mastic brush on all branch connections. The branches were pretty easy, just got more flex duct, pulled the inside tube and slipped it onto the branches. They too were retaped, and mastic sealed. I received 3 quotes all over 6k-7k for replacement and repair. I did everything much cheaper and with better materials and installation measures for only $1, 300. Using sales and veteran discounts I got better R value and used today's sealing practices. So, I strongly disagree that a professional should do something that any handyman can easily do. Lastly, I have seen really bad professionals, all the good ones charge higher prices and still cut corners.

[williamgrissom]

I didn't know that insulating ducts is life-threatening, but only step on wood in an attic and watch for nails thru the roof (ow), or in a crawlspace don't touch a bare electrical wire while lying in a puddle. Good lighting helps a lot.

Step one is to seal all joints, which means cutting open the insulation at each connection. In older days (and even gomer techs today), they didn't coat joints with duct sealant, so many leaks. Doesn't matter inside the house envelope, but much waste if the ducts are in a crawlspace or unconditioned attic. Then tape the old insulation back and best to cover that with new foil-covered insulation, taping the joints.

[fastrivers]

I have a square/rectangular return air duct in my attic and I believe that it's sucking attic dust/fiberglass insulation particles into our home and causing our allergies to become inflamed. It's around 15' - 20' in length and not something I feel comfortable pulling out to tape. The main reason why is I dread trying to refit it back to everything that it is attached to as it has a few intakes that it's attached to.

The duct sits between two joists that run alongside it so I cannot get mastic or butyl tape on the sides and bottom. Can I just cover the venting w/ plywood, attaching it from joist to joist so it stops sucking in fiberglass insulation particles and dust? I figure I could put some type of dry gasket sealer between the plywood and joists to prevent air from getting vacuumed in.

[MyMule]

Hey Thanks for teaching your
JOURNEYMAN SUPERINTENDENT

[Inkling]

You're right about adding duct insulation being a pain. I lack the skill to replace the flexible ductwork in my attic and it was still in good condition. So I bought some in a larger size, removed the metal coil, and wrapped it around the existing flexible ductwork with nylon ties. That turned it from a pitiful R7 to a slightly less pitiful R14. Throughout the messy process I kept thinking, "Why doesn't someone make flexible insulation designed to be placed around what is already there?" Leave it open at the bottom and have a series of steel loops that would let it snap around the existing insulation. It'd be cheap and quick to install. It would certainly better than what I had to do in that blazingly hot attic. There's a business opportunity there for someone.

[Perly]

Thanks so much. I have 1130 sq ft CBS 1973 one story home in East Central Florida. The ductwork is in the attic. There is a package unit on the east side of the home that the duct runs up the interior wall (using part of a bedroom closet) into the attic to a plenum that splits into 8 ducts (2 bedrooms, 2 baths (between the bedrooms), entry, dining, living and kitchen (all open to each other). The ductwork is original (R4) and truly needs replacing. A local a/c company suggests a man that would come out and do an entire evaluation for $800. But I was thinking of just getting the duct work replaced (R8?) and hope that will make a big difference. I can't do it myself but I wonder what you think.

[wstt]

Is a plenum box needed for the supply side of AC or could metal Y’s be used? About 10’ from my handler is a plenium box that comes in with a big foil duct (maybe 16”) and exits the box at a right angle and exits with 3 different sized foil ducts (10”, 6” and 4”). Couldn’t i just use a Y into another Y to keep the air flow running straighter instead of a right angle and eliminate the box? I assume making right angles slows air flow. (The rooms with the 6” and 4” ducts don’t get as cool. I Was going to install in line booster fans for them too.). (Hawai’i so AC only, no heat).

[bigpapparay]

I'm dealing with extreme sweating in bend new mobile home duct work from AC in this extreme humidity in South East tn and they don't wrap them at all and now I have water damage and even worse mold growing around for Joists! Gone wrap it but not sure what kind I would need! Help?! Lol

[cosmoscarl]

I have a safety and air quality questions. We moved from one old apartment complex to another old complex and my wife has had increasingly severe allergic reactions since we moved here. We moved from the old apartment for multiple reasons but one was her allergies, which have become much more severe since we moved. I usually have i higher tolerance than she but I've been increasingly sick and tired since we moved. She has missed increasingly more work from her illnesses. My questions are, 1. Is inside duct insulation still a common product used? 2. Is old inside duct insulation more prone to breed mold and mildew and cause problems with allergies and illnesses? (I'm thinking, yes, to that question. )3. What are the apartment managers responsibilities to tenants, (especially ones without renters insurance), to remove old duct works that may be full of toxic mold or mildew, or to hire experts to mitigate the probles? I can clearly see that the ducts are old and most likely riddled with mildew and mold. The original color under the surface of the insulation is yellow, which is visible in ducts farther from the central unit, but are black nearer the central unit. The apartment we live in now was said to have sustained smoke damage from an apartment fire in the unit behind it some time last year and the manager told my wife that it was completely remodeled, including new sheetrock, cabinets and carpet. However the ducts are obviously original. Our past experiences when we were younger were that apartment owners usually do as little as possible because of budget restraints and owner politics. (They're trying to save money at the renters peril.) Especially in old apartments like these where the rent is cheaper than the newer, more upscale apartments. My wife and I are in our 50's and we seem to be more sensitive to these issues than we were when we were younger. I'm thinking there isn't much we can do about this except ask if they can have the unit checked by professionals, but I doubt they would even do that. They would probably send a makeready to inspect it. And from what I've seen of maintenance men and makeready's here, they're not very skillful or intelligent. I noticed that ducts with insulation on the inside are still being sold but these are obviously old, full of poison and that it would be a very expensive and extensive fix if they would even consider doing that at all. Probably the best we could hope for is to be moved to a different unit but I doubt they would even offer that. There's always the question of availability of a similar sized unit. Sorry for the novel. Any advice?

[grotowin]

I have a question, on round metal duct work return air systems, specifically adjacent pipe connection, does the return air duct have to follow IRC Chapter 16 Duct Lap rule (male end of the duct shall extend into the adjoining duct in the direction of airflow). I understand the Supply air needs to follow this principle, but does the return air branch duct connections need to follow this rule as well?

[Chris-jgcl]

I have 23 year old duct board truck lines in my house and have been having ongoing health problems ever since moving into the homes 7 years ago. Doctor and testing has ruled out mold and ultimately thinks it’s the fiberglass particulates from the old duct board.
I am wondering what options there are out there that would be better? Thanks!

[thuytoman]

Would it worth the cost to have ductwork spay with foam?

[larrylupe]

Would have loved to see more information on the spacers and insulation used in the thumbnail....

[micahbarton]

I bought a house in Colorado Springs. It’s never had A/C but I’m wanting to have it installed. None of the ducts are insulated but the entire unit and duct work is inside the house (unit and ducks run in the basement). Do I need to insulate all the ducts in the house? If I do, Is there a good way to insulate the ducts without tearing out drywall? Lol

[dh]

I often make curb adapters, and combined curb plenums where only a sheet metal divider separates supply, and return. For the life of me I can't find an answer for what R value liner I should put on the divider, if any, assuming a Delta T, or maximum temperature difference of 22° F between supply, and return. The sheet metal alone should lessen the temperature difference.

[Pinky.skullz]

I bought a 55 year old house that was not maintained. Right now I cannot afford to have the ducts replaced. Some of my ducts are rusted through. I'm looking at a double sided radiant barrier to try and make it kast until I can afford to have it all replaced. Due to some of the ducts being rusted through, I'm leary about the fiberglass faced wrap. What would you recommend?

[thepitpatrol]

In your opinion is flex duct good under a house.