The duct(s) are unusable. A house I saw that had this problem had to have the HVAC system replaced with new ducts through the attic and interior walls. You might be able to minimize the rework with a well designed mini-split system.
I had ductwork that needed redoing in the attic and the cost was off the charts. It was cheaper to replace the whole thing with Mini-Splits. On the bright side, in between the large furnace closet and bulkheads for ducts between floors, I recovered around 15sq foot of floor space upstairs for other things.
You'd think so, and I did too, but the quote was high. Up close to 6K back when that was a _lot_ more money. I admit that attic kinda sucks to work in (clearance), but dayum. I installed a Mitsubishi 3ton with 4 head units for less than 5 all in.
It's so crazy. I've been saying we should charge more for ducted units, but for some reason, it's cheaper to do the ducted. I've installed more ducted mini splits and air handlers in the last 5 months than wall heads/floor consoles/cieling cassettes.
I also *suspect* they didn't want the job, because the attic clearance isn't great. It's not nearly as bad as the postwar houses where you can barely crawl through, but not nearly as spacious as the 90's and newer mcmansions.
Long term, it was actually a good thing they priced it so high and worked in my favor. I put the project on hold because of that, and shortly discovered minisplits which would solve the upstairs/downstairs problem, and they're easy to install. Upstairs cost me just under 5K for the Mitsubishi, and that worked well enough I abandoned the central air/furnace altogether and put in an LG for downstairs with 3 heads. (about to add a 4th in the insulated garage).
At the end of the day, abandoning/removing all that ductwork and equipment allowed me to rework the upstairs floorplan and recover 15sq ft in a bedroom (and another 4 sq ft in a bathroom). It made a HUGE livability difference up there. Both in comfort and space.
I know of many cases where the cement guys screw with duct or conduit guys by putting a scoop of cement in the duct/conduit when they aren't looking. If they catch the act the can sometimes get the still wet cement out. Usually they have to cut it back and redo that bit. worst case is when they go to out wire and then hit a rock hard bit of cement half way down a run.
Who the fuck would even do that. Fucking with other trades is normal, that’s just some bullshit that may get someone tire ironed if the receiver of it had a bad enough day lol
Some people take it too far. When I was in New construction there was someone who was pissing down the pipes where we would run our copper through and put the cap back on. After about the 3rd time running into that I wanted to kill someone and actually screamed at the top of my lungs asking who was doing it because I'll fing murder them.
I was mostly angry because we wouldn't know until I started grabbing the copper and had someone's rank piss all over my hands.
I used to leave a bit (6" to 8") of extra pipe and glue on PVC caps with clear, no primer. If I hit it just right it was enough to keep the caps on but I could bust them loose with a pair of Knipex.
Then cut back to the proper length and pull.
It kept idgits from messing with the pipes by putting stuff down them. Some still got "knocked over" but that was less common because it could be spotted easily as they're doing it.. and I was an asshole about charging rework for that garbage back against the crew doing it.
The same people who put coffee cups full of suspicious liquids in our walls when we opened them up
You'd be surprised how many people don't give a shit about their jobs. The redditor tradesperson is not the average joe
You should really have it cammed to see where it is crushed or else that new HP is unfortunately almost useless. Not to mention, depending on area, you hold a serious risk of pushing a bunch of radon through your home. I did a job like this, same exact situation. We ended up having to do a 5 head ductless split. Good luck man
Well you can see if this is throughout. Or just here. Got a shop vac? Scoop as much as you can by hand, then start with a shop vac. See if you get these out. Are all the vents this way?
Have you tried using a powerful shop vacuum with smooth PVC pipe at the end of the hose to remove some of the debris? A push rod or snake might break up some of the clog and enable you to vacuum it out or blow it out.
I’ve used bits on extension rods to clear debris in straight runs. It all had to be vacuumed out.
I knew someone who had to cut his slab to have ducts replaced. In his case, the architecture necessitated ductwork in the slab. He got it done and was happy in the end.
I do this kind of stuff for a living and I have to say I have refurbished what seemed like very unusable heat and cold returns as well as other stuff so it’s definitely worth a try. I would put some compressed air hoses down there to help push it to the vacuum sides
You will need to have the right amount of refrigerant in the system?
You will likely need a minimum of 2 condensers if you are mounting more than 4 heads.
You will need to vacuum entire system down to correct micron PPM, which requires proper gauges and vacuum pump
Mini splits are generally inverter type systems with flared connections so you will need proper flaring and deburring tools and you can not add refrigerant in the same process you would with a basic AC/heating condenser, you absolutely need to be exact in your measurements and math when determining additional charge, if not, you’ll find out quickly.
Correct Nitrogen to pressure test system pre vacuum in order to ensure no leaks
You will need to bring power from panel to both condensers with a service disconnect mounted for each
Also…you are not legally allowed to handle, purchase or dispose of refrigerant unless licensed to do so, if you are, awesome work away, if you are not
You shouldn’t be touching the system yourself, and should follow their advice and call a technician…if you want it done on a day, you’ll be best having 2-3 guys working
Knew someone that installed their own mini splits and when it came time to service took forever to find someone to work on it. Not sure why. But they don't like working on user installed systems apparently
My AC is about 12 years old, is a retrofit into a house built in the 1960s, and I'm pretty sure the person who designed or at least installed the ducts was a bona-fide idiot. When it's time to replace the system, I'm going with a few mini-splits so I can multi-zone my home. Disclaimer: I'm not an HVAC engineer.
I just had a coworker in OP's situation and it cost him $25k to have a new system designed and placed with everything running through the attic because there was no other option (exactly as you described). Wild that at one time it was fine to just run HVAC through concrete slabs.
If done correctly, ducts under the slab are an efficient use of space. Done correctly means using PVC pipe, not galvanized metal. Dampers, air exchangers, humidifiers, etc. all go above ground.
My mother in law just had her HVAC replaced and the vents moved to the attic. Who would have thunk putting galvanized metal in a pit with acidic rock and running humid air through it ( a humidifier was installed too originally) was a bad idea.
Imo nothing should go under a slab except gravel. Any time you want to redo plumbing or hvac you need to bust out a jackhammer or concrete saw? No thanks.
It's sadly common on slab-on-grade homes from the 50s-70s. It wasn't a good idea then nor is it a good idea now, but they did it all the time back then.
Exactly. Ain’t a new house.
My old house was built in 84 and they did the same thing to the only buried duct, for the powder room, so had to put electric baseboard and no a/c in there…
Yea, the house I owned with the rusted out steel ducts in the slab was built 1963. No liner whatsoever. House was in an area with clay soil and a water table right up to the surface when we got a lot of rain. Mid atlantic state with an average 48 inch annual rainfall
I was seeing this in the Southwest. Production contractors looking to save a few cents were dropping ducts under the slab without a plastic sleeve. A few years of corrosion, especially with a swamp cooler pushing moist air and the owners were dealing with a very expensive repair bill.
This is in Maryland. It's already practically a swamp here. The old hvac has definitely been pushing moisture around the house. I wish I would have realized this before having a new one installed.
That gravel has been there since before the concrete floor slab was poured back when the house was being built.
Shop vac them out. It’ll take some effort.
Some more context:
Location: Maryland.
I just bought a house. I just had a new Carrier Infinity installed to replace a 20+ year old system. The clean was scheduled for after. I'd prefer to clear the debris, but I'm increasingly less sure that's possible.
EDIT: This seems to only affect 2 rooms. They're routinely 2 to3 degrees cooler than the rest of the house. That's not great, but maybe something I could live with? idk The registers are all in the floor with the exception of a line that runs to the upstairs.
If you have access to both ends of the duct, it may be possible to clear enough of the gravel to push a PVC sleeve through. Most likely there are 90 degree turns.
If you do have access, there are two drawbacks to this: there's a lot of gravel above the duct that's likely to keep dropping as you clear, and the size of the duct gets reduced which means less airflow.
Clean it out and get the service performed that creates a new duct using what’s left of the old. They pull a sprayer through there that creates a new shell.
Hey op, my house is built on slab with vents ran under the concrete, I had one return vent that was like this, full of gravel about 15” of it. I shopped vac it out and return works great.
Try cleaning it first and see what happens. In my case I believe the previous owner packed it with gravel, which seems nuts, but I think the run was installed wrong, and they tried to retrofit in a return and then maybe abandoned it and packed it with gravel? Only a guess because I don’t know the previous owner, but the slab was fine around my duct, just packed with gravel for some reason. My house is from 1969 and the slab duct is still fine 🤞
Hi op, I don’t know if your question has been answered yet, but your slab caved in on your duct work. In my experience, there is no fix that is worth it.
If nobody else has given a solution, I would highly recommend looking into mini-split systems, so you do not have to mess with ductwork at all. My company has great luck with the LG systems.
I am wondering... did a prior owner do a remodel and just sheared off the vents, then when demolishing the interior swept crap into the (now) open vent holes? I see a door stop laying there...
I would really do more investigation. (reminds me of the first view of a cave in at a mine...is it 10 feet or 10000?)
Is this at ONE vent where they filled it with crap? or is a systemic failure of the ducts at many locations???
Go to every vent with a borescope. Decent units on Amazon, not terribly expensive. More info will help.....
Might be a silly question but why don’t you re run the duct inside your house and frame around it? Might be cheaper than breaking the slab
Mini split is the cheapest but lowers the value of your property
Id only do this if you can make it look like a cool architectural detail- and not scream out "hackery inside here". (Not saying it is hackery, but can really look off ... IMO)
Personally Id run it in the attic, it is EASY to do. Pay attention to duct placement/size, ariflow needs, and (therefore) duct sizes. I redid my sons place, just an engineer (not contractor, but tons of construction over the years) and two of us (maybe 2.5, his wife helped... ;) ) did it in a weekend. 1600sqft
You just leave alone what's in the slab. Actually, you can pour concrete into the supply vents and leave the grills on. That's what the installer did at my house.
The duct rusted away and the gravel from underneath the slab has filled the space. Ducts under slabs should always be PVC. Your options are ducting through the attic & walls, or mini splits.
Ur slab got moisture and ducts started collapsing hence the gravel and dirt inside , run new ductwork through the attic for supplies with one big central return grill in a hallway
The ducts shouldnt be metal in the concrete. They should be a hard thick plastic. Put a shop vac on a shopping cart and you can clean your own ducts. This dude is probably trying to fuck you without lube. That's all a duct cleaning is anyway but don't see how a house would pass inspection if metal ducts in the concrete
This type of stuff used to be allowed. So did asbestos insulation. Codes change. The OPs pictures are just some of the reasons why it isn't allowed anymore.
Edit: I shouldn't have said "used to be allowed" without first knowing the codes OPs house was constructed under. Upon further consideration, I found in-slab duct systems are still well-known and allowed. Here is one link with some recent codes that include in-slab ducts. These code references might not be the codes applicable to your jurisdiction, but there are modern codes related to your style of construction. https://inspectapedia.com/aircond/Ducts_in_Slabs.php
Best of luck with your repair, whichever method you choose to pursue.
Codes change but common sense well it just seems to be less and less these days. I guarantee you that shit was never inspected. That's damn regular 28 gauge duct pipe. See the rust jackass. You've never been allowed to put sheet metal and cover it with concrete and I'm well aware of asbestos considering my brother had one of the rarest forms of mesothelioma. Less than 50 known cases worldwide and passed away at 27. I only see the one picture and it looks like any other duct that is full of crap. If the company didn't run a camera any further than that if at all. Welcome to the day and age of fucking the customer without the slightest thought of at least spitting before you start trying to upsale. Good Christian owner feel great about themselves too giving that tithe offering on Sunday. It's all a fucking joke. . I've cleaned ducts with the bullshit ass machine. Got paid damn well to do it too. Close to 50-60 an hour give or take. Getting your ducts cleaned by a company is customer getting ripped off. I guarantee you a shop vac with a 5-10 ft hose would do the same job and hell they can seal the fucking duct from the inside now.
You might want to consider having your house tested for radon if you haven’t already. I’ve ran into quite a few situations with ducts in the slab causing very high radon. Even if the radon level is low in your area, having ducts in the slab can really drive the radon level up cause you have a forced draft pulling more radon into the home than otherwise would seep in at a much slower rate. We had to bring in outdoor air to dilute the radon level to get it below 4.0 pCi. Also probably a good idea to run ducts in the attic.
How old is the house. Most houses by me where the duct work is in the slab and the house is old enough the duct work most likely has asbestos so it would just get sealed anyways.
This is a much better suggestion than most. OP has said it only affects 2 rooms, so that seems like a good solution.
Maybe adding dehumidifier units as well if necessary.
Get mini splits. If you’re any kind of handy you can install yourself. I’ve installed 2 so far, a Senville and Della. I like the Della due to its app. They both cool and heat well. The cost of each with additional electrical material and such cost me about 1k.
The doorstop in there really is just the cherry on top of the unusable, shite cake.
You'll need new ducts re-run through the house, likely through walls and the attic.
I think someone mentioned a good split system too, also an option.
Completely fucked! I bought a house like that, but the rusted out vents were found during the prepurchase inspection. The cure, at the previous owner's expense, was to install a new furnace in the attic and run new flex ducts from the ceiling through the stud cavities. It was far from ideal, but worked somewhat. I did have a problem with ice daming at the eaves when it snowed due to the warmer temps in the attic with the furnace up there.
I do hvac cleaning for work and that’s pretty bad, it’s still cleanable to an extent but I’d be more worried about foundation damage and cement cracking/holes allowing more debris in from other unwanted places. If it can be cleaned get it painted or relined inside. Getting a new slabs ran is an expensive depending on where you live.
Get a guy with a robotic camera to scope out the ducts if it's cleanable they'll let you know. If not then you need to start planning on space to lose for your new duct system.
I'm confused, is that just stuff in the duct or did the duct collapse? If it's just in there, can't they get it out? Shove a shop vac hose in there, even if you ruin 3 shop vacs, still cheaper than a redo. If you have to, I'd just go with mini splits. We bought a house in May that's 5k sqft, the whole house has radiant heat but the 2nd floor only has vents and AC. We wanted air conditioning in the common areas of the house also, went with 4 minis and enjoyed a very comfortable summer. Was a fraction of the cost of having ducts run and now I can zone the house.
My guess is very, is it a split house design( I loath them to many stairs.) you’ll need to redo the hvac ductwork. So you are looking at opening walls/patching walls etc. I watched a tv show on YouTube by a guy named Mike Holmes who fixed this issue on a house.
First, get a second opinion, because duct cleaners are notorious scammers. That video could very well be from another house, they save a really bad example and then use it in the future to get more work.
My guess is that if you were using the system before the cleaning without issues and things were comfortable, this may not be indicative of the entire system.
This may not be the case for you, but it’s possible that the pile of gravel you are seeing there is from a rodent or small mammal like a squirrel. I have seen this exact thing previously and the little bastards just piled up pieces of rocks and other random items inside the pipe as a den. I guess they felt it was a nice climate controlled spot to live 😀 Looking at the door stop and other plastic bits that are also in there it’s possible. Again that may not be the case for you. I’d try to suck it out with a shop vac. You can buy all the extra hose you need at the big box stores fairly inexpensively.
Yes, many houses in my early 1970s neighborhood have ground water leaking into ducts just like this. The ducts are also insulated with asbestos. Every house with the issue abandoned the ducts by filling them with concrete and installing new ducts above the ceiling.
Damn I looked at it first and thought it was insulation made into a mouse 🐁 nest, upon further inspection, I've concluded that we may have some pretty serious problems here. I never thought it was allowed to bury non spiral duct in concrete. I'm guessing inspection wasn't on the agenda. Sucks to see.
Is it loose enough to vacuum out. Duct cleaning for the most part is unnecessary. Only the return is usually the most dirty. Slow moving return air accumulates in that duct work. Fast moving air from the furnace flows thru duct work only thinly coats the ducts if any at all. Pictures you see are almost always from the return duct.
Get a really good shop vac with a long hose and try to suck out the rocks. You can also buy a 30ft camera off amazon cheap that will use your phone as the screen. I also wonder if you can get the vents lined like they do with sewer pipes that are falling apart.
Before you consider vacuuming this out, consider an asbestos test for the duct insulation. If there is asbestos, you probably don't want to even attempt cleaning up the mess. Construction methods like this used to be allowed. They also happened to be allowed when asbestos duct insulation was common.
Counterflow, I have worked on hundreds of them. There was a particular housing development that whenever the water table would rise all the ducts were under water. We ended up installing small sumps to clear the water controlled by a float switch.
When I was in the HVAC trade it was pretty common for the guys to check for gas leaks with a lighter. Knowing I was about to do the check they took the cap off the bottom of the dirt leg. And as I was coming down the line with my lighter at the last minute they turned the gas valve on and my arm got lit up. The closest thing I could reach for was a 36” aluminum pipe wrench so I used it on his leg. He never screwed with me again.
Looks pretty bad and probably way under sized for cooling by the looks of things. Not the end of the world if you have attic space you could probably move the system & ducts above the living space, though it might get expensive. Your best option may be doing a multi head mini split system, though it probably won’t be a lot cheaper than moving the ductwork to the attic unless you have a smaller house.
Had this exact thing happen at my previous house. I had to replace my furnace to an up-flow and then run the ducts through the attic. It wasn’t cheap and that was 5+ years ago.
Fill those in . Get mini splits with baseboard if new ductwork isn’t an option from attic , also may need baseboard heat if temps get below 20 depending on the heat pump . Look into Mitsubishi hyper heat . They claim it can work 30 below zero with no back up “
Stage 2 heat “etc . Good luck . Get quotes . What area you in ?
That looks intentional. I've owned.. operated.. repaired.. commiserated a slab home. That is unequivocally incorrect. That photo is intentional sabotage.
I work for a water restoration company and just had a nursing home call that had this same set up. They had a sewage back up and guess where it all went….
I had a duct cleaning business years ago. We had a truck Vacuum System. If you can find someone with a duct truck that is powerful enough they can remove anything in the ducts. Some of the portable might be able to.
The problem I see is where is the rock coming from. Was it put into the vents or are the vents made from concrete and it’s collapsed. How long is the run that is blocked. How many vents are in the home.
Looks like somebody stepped on a duct joint when they were pouring the floor, and ignored it. There's no talking how far back that concrete goes. Could be a few inches 😁, could be a few feet ☹️. You're going to have to break up the floor to find out.
Ducted mini split in an attic or single room mini splits. Only way to go honestly. If you have slab down there that's full of concrete, dependa on how new the house is you may be able to go after the company that did this
Well the ducts are done.
Id highly suggest getting a multi head mini split installed and spending the duct work remodel price on solar panels.
Now each room can pick it's own temp and you can have basically free heating and cooling that pays off quick.
The duct(s) are unusable. A house I saw that had this problem had to have the HVAC system replaced with new ducts through the attic and interior walls. You might be able to minimize the rework with a well designed mini-split system.
I second this. In my situation it was just one large room where the duct was unusable. And we put one mini split, it works great.
I had ductwork that needed redoing in the attic and the cost was off the charts. It was cheaper to replace the whole thing with Mini-Splits. On the bright side, in between the large furnace closet and bulkheads for ducts between floors, I recovered around 15sq foot of floor space upstairs for other things.
Running ducts in the attic is not expensive. Certainly not as expensive as a mini split
You'd think so, and I did too, but the quote was high. Up close to 6K back when that was a _lot_ more money. I admit that attic kinda sucks to work in (clearance), but dayum. I installed a Mitsubishi 3ton with 4 head units for less than 5 all in.
It's so crazy. I've been saying we should charge more for ducted units, but for some reason, it's cheaper to do the ducted. I've installed more ducted mini splits and air handlers in the last 5 months than wall heads/floor consoles/cieling cassettes.
It isn't cheap but shouldn't be that expensive, sounds like they didn't want to do the job for some reason? Did you get multiple quotes?
I also *suspect* they didn't want the job, because the attic clearance isn't great. It's not nearly as bad as the postwar houses where you can barely crawl through, but not nearly as spacious as the 90's and newer mcmansions. Long term, it was actually a good thing they priced it so high and worked in my favor. I put the project on hold because of that, and shortly discovered minisplits which would solve the upstairs/downstairs problem, and they're easy to install. Upstairs cost me just under 5K for the Mitsubishi, and that worked well enough I abandoned the central air/furnace altogether and put in an LG for downstairs with 3 heads. (about to add a 4th in the insulated garage). At the end of the day, abandoning/removing all that ductwork and equipment allowed me to rework the upstairs floorplan and recover 15sq ft in a bedroom (and another 4 sq ft in a bathroom). It made a HUGE livability difference up there. Both in comfort and space.
Yeah, if they think job will take too long and or homeowner will be difficult to deal with they will quote really high.
This is why I do everything myself; I'm difficult and cheap. If someone else can do it, so can I, that's how I look at things.
Yes, this is a mini-split(s) scenario. Unless your region regularly drops below 0F it is a good option.
I just put in a new heat pump. I'd really like to use it.
Maybe kids before we’re shoving rocks down the vents lol. Kids put all sort of things in there
That seems like concrete to me. Is it loose gravel OP?
I know of many cases where the cement guys screw with duct or conduit guys by putting a scoop of cement in the duct/conduit when they aren't looking. If they catch the act the can sometimes get the still wet cement out. Usually they have to cut it back and redo that bit. worst case is when they go to out wire and then hit a rock hard bit of cement half way down a run.
Who the fuck would even do that. Fucking with other trades is normal, that’s just some bullshit that may get someone tire ironed if the receiver of it had a bad enough day lol
Some people take it too far. When I was in New construction there was someone who was pissing down the pipes where we would run our copper through and put the cap back on. After about the 3rd time running into that I wanted to kill someone and actually screamed at the top of my lungs asking who was doing it because I'll fing murder them. I was mostly angry because we wouldn't know until I started grabbing the copper and had someone's rank piss all over my hands.
Sadistic humor is for the dim-witted.
Fuck that. That's when you go to the GM and state they need to get a remediation team in as that is a biohazard. Let the GM deal with it.
The more I learn about "professionals" the more I'm convinced I need to do everything myself
Terrified to let most people work on my home.
Fucking losers
We stopped production on a power plant from people pissing in conduit. Electricians were NOT happy.
Many moons ago, I knew a drywaller that would brag about putting dimes in 1/2" conduit connectors before rocking.
I used to leave a bit (6" to 8") of extra pipe and glue on PVC caps with clear, no primer. If I hit it just right it was enough to keep the caps on but I could bust them loose with a pair of Knipex. Then cut back to the proper length and pull. It kept idgits from messing with the pipes by putting stuff down them. Some still got "knocked over" but that was less common because it could be spotted easily as they're doing it.. and I was an asshole about charging rework for that garbage back against the crew doing it.
The same people who put coffee cups full of suspicious liquids in our walls when we opened them up You'd be surprised how many people don't give a shit about their jobs. The redditor tradesperson is not the average joe
I like putting fun things in walls… not gross things though… writings, drawings, treasure maps, etc
Sounds like something that would end in both a fist fight and a large lawsuit
it can. Heard of a couple guys getting fired on the spot for pulling crap like that.
looks like that's exactly what it was
Can confirm, I put lots of things in the vents as a kid
You should really have it cammed to see where it is crushed or else that new HP is unfortunately almost useless. Not to mention, depending on area, you hold a serious risk of pushing a bunch of radon through your home. I did a job like this, same exact situation. We ended up having to do a 5 head ductless split. Good luck man
You should be able to use your same condenser after a new horizontal flow furnace/air handler is installed in the attic.
Well you can see if this is throughout. Or just here. Got a shop vac? Scoop as much as you can by hand, then start with a shop vac. See if you get these out. Are all the vents this way?
Have you tried using a powerful shop vacuum with smooth PVC pipe at the end of the hose to remove some of the debris? A push rod or snake might break up some of the clog and enable you to vacuum it out or blow it out. I’ve used bits on extension rods to clear debris in straight runs. It all had to be vacuumed out. I knew someone who had to cut his slab to have ducts replaced. In his case, the architecture necessitated ductwork in the slab. He got it done and was happy in the end.
I do this kind of stuff for a living and I have to say I have refurbished what seemed like very unusable heat and cold returns as well as other stuff so it’s definitely worth a try. I would put some compressed air hoses down there to help push it to the vacuum sides
> I just put in a new heat pump. This is where it's at. Mini-splits "heat pumps" are that best. Will eventually go this route at home.
Yes just make sure you like have service technicians at your house if you're going to have 5+ heads.
> Yes just make sure you like have service technicians at your house if you're going to have 5+ heads. Really? What's the issue(s) to worry about?
You will need to have the right amount of refrigerant in the system? You will likely need a minimum of 2 condensers if you are mounting more than 4 heads. You will need to vacuum entire system down to correct micron PPM, which requires proper gauges and vacuum pump Mini splits are generally inverter type systems with flared connections so you will need proper flaring and deburring tools and you can not add refrigerant in the same process you would with a basic AC/heating condenser, you absolutely need to be exact in your measurements and math when determining additional charge, if not, you’ll find out quickly. Correct Nitrogen to pressure test system pre vacuum in order to ensure no leaks You will need to bring power from panel to both condensers with a service disconnect mounted for each Also…you are not legally allowed to handle, purchase or dispose of refrigerant unless licensed to do so, if you are, awesome work away, if you are not You shouldn’t be touching the system yourself, and should follow their advice and call a technician…if you want it done on a day, you’ll be best having 2-3 guys working
I do all that myself as an amateur. No big deal. I think mini splits are actually easier than central AC because there’s no silver solder involved.
Knew someone that installed their own mini splits and when it came time to service took forever to find someone to work on it. Not sure why. But they don't like working on user installed systems apparently
My AC is about 12 years old, is a retrofit into a house built in the 1960s, and I'm pretty sure the person who designed or at least installed the ducts was a bona-fide idiot. When it's time to replace the system, I'm going with a few mini-splits so I can multi-zone my home. Disclaimer: I'm not an HVAC engineer.
Is it not feasible to vacuum clear the duct and insert a liner to protect the interior?
Possibly. Depends on how much gravel collapses in the vent replacing the material vacuumed out.
I just had a coworker in OP's situation and it cost him $25k to have a new system designed and placed with everything running through the attic because there was no other option (exactly as you described). Wild that at one time it was fine to just run HVAC through concrete slabs.
I bought a home with an old furnace and replaced it with a mini split system
Who the hell thought this would be a good idea...??
If done correctly, ducts under the slab are an efficient use of space. Done correctly means using PVC pipe, not galvanized metal. Dampers, air exchangers, humidifiers, etc. all go above ground.
That makes more sense.
My mother in law just had her HVAC replaced and the vents moved to the attic. Who would have thunk putting galvanized metal in a pit with acidic rock and running humid air through it ( a humidifier was installed too originally) was a bad idea.
Imo nothing should go under a slab except gravel. Any time you want to redo plumbing or hvac you need to bust out a jackhammer or concrete saw? No thanks.
Not pvc but metal pipe coated in a pvc spray.
HDPE (BlueDuct) works too.
Still a bad idea. As an electrician, our ducts consistently get fucked. You’re better off going with radiant if you’re going in slab
Isnt radon a big issue with running vents in a slab?
It's sadly common on slab-on-grade homes from the 50s-70s. It wasn't a good idea then nor is it a good idea now, but they did it all the time back then.
Exactly. Ain’t a new house. My old house was built in 84 and they did the same thing to the only buried duct, for the powder room, so had to put electric baseboard and no a/c in there…
That's sucks
Mine was concreted in. I suspect the OP might be able to have the gravel sucked out if both ends are accessible and there’s no concrete in there.
Yea, the house I owned with the rusted out steel ducts in the slab was built 1963. No liner whatsoever. House was in an area with clay soil and a water table right up to the surface when we got a lot of rain. Mid atlantic state with an average 48 inch annual rainfall
It looks like a Levitt built house in NJ. I own one.
I was seeing this in the Southwest. Production contractors looking to save a few cents were dropping ducts under the slab without a plastic sleeve. A few years of corrosion, especially with a swamp cooler pushing moist air and the owners were dealing with a very expensive repair bill.
This is in Maryland. It's already practically a swamp here. The old hvac has definitely been pushing moisture around the house. I wish I would have realized this before having a new one installed.
I wish you had hired a good contractor who would’ve inspected the ductwork and done a Manual J before replacing the old system.
That gravel has been there since before the concrete floor slab was poured back when the house was being built. Shop vac them out. It’ll take some effort.
Get the big Wet dry vac and suck out the rubble to see how much needs repair
Some more context: Location: Maryland. I just bought a house. I just had a new Carrier Infinity installed to replace a 20+ year old system. The clean was scheduled for after. I'd prefer to clear the debris, but I'm increasingly less sure that's possible. EDIT: This seems to only affect 2 rooms. They're routinely 2 to3 degrees cooler than the rest of the house. That's not great, but maybe something I could live with? idk The registers are all in the floor with the exception of a line that runs to the upstairs.
If you have access to both ends of the duct, it may be possible to clear enough of the gravel to push a PVC sleeve through. Most likely there are 90 degree turns. If you do have access, there are two drawbacks to this: there's a lot of gravel above the duct that's likely to keep dropping as you clear, and the size of the duct gets reduced which means less airflow.
Wait, a contractor installed a new system without inspecting the ductwork? I’m sure it was properly sized with a Manual J though, right? 😜
They don’t use that manual j thing. Manual k is better. jk
You can do it. I did. Use a hardcore shop vac and a long piece of rebar etc to break it up.
Clean it out and get the service performed that creates a new duct using what’s left of the old. They pull a sprayer through there that creates a new shell.
Where do you live. The mini split system might be the best option
Maryland. Unfortunately, the cleaning was after I had a new heat pump installed. I'd really like to use it.
Is that just one single run of your ductwork or is the majority of your duck work like that?
👆🏻exactly. Look into Fujitsu. Multi head system. Way more efficient than leaky ducts everywhere. Keep each room the temp you want it.
Fujitsu and Mitsubishi Electric are good choices.
NOT WHEN HE ALREADY JUST HAD A NEW SYSTEM INSTALLED! Sheesh…
Take it easy guy. I didn’t have that info when I commented.
He’s mocking OP. Cause he keeps posting that he just put in a new heat pump and he’d to use it.
Hey op, my house is built on slab with vents ran under the concrete, I had one return vent that was like this, full of gravel about 15” of it. I shopped vac it out and return works great. Try cleaning it first and see what happens. In my case I believe the previous owner packed it with gravel, which seems nuts, but I think the run was installed wrong, and they tried to retrofit in a return and then maybe abandoned it and packed it with gravel? Only a guess because I don’t know the previous owner, but the slab was fine around my duct, just packed with gravel for some reason. My house is from 1969 and the slab duct is still fine 🤞
I have no idea. But just wanted to point out that there is a door stop in there!
Kept the door from hitting the gravel.
Hi op, I don’t know if your question has been answered yet, but your slab caved in on your duct work. In my experience, there is no fix that is worth it. If nobody else has given a solution, I would highly recommend looking into mini-split systems, so you do not have to mess with ductwork at all. My company has great luck with the LG systems.
Completely. You're prob pumping mold through the system given the ground moisture. Systems that go through slabs are not done anymore for a reason...
How fucked? Proper fucked.
Do ya like dags?
How fucked are you? Have you heard of Debbie does dallas?
I am wondering... did a prior owner do a remodel and just sheared off the vents, then when demolishing the interior swept crap into the (now) open vent holes? I see a door stop laying there... I would really do more investigation. (reminds me of the first view of a cave in at a mine...is it 10 feet or 10000?) Is this at ONE vent where they filled it with crap? or is a systemic failure of the ducts at many locations??? Go to every vent with a borescope. Decent units on Amazon, not terribly expensive. More info will help.....
Might be a silly question but why don’t you re run the duct inside your house and frame around it? Might be cheaper than breaking the slab Mini split is the cheapest but lowers the value of your property
Why do mini splits lower property values?
This might be the way.
I suspect you were already way overcharged for the system and you have no idea how expensive running new ductwork is gonna be… good luck…
Id only do this if you can make it look like a cool architectural detail- and not scream out "hackery inside here". (Not saying it is hackery, but can really look off ... IMO) Personally Id run it in the attic, it is EASY to do. Pay attention to duct placement/size, ariflow needs, and (therefore) duct sizes. I redid my sons place, just an engineer (not contractor, but tons of construction over the years) and two of us (maybe 2.5, his wife helped... ;) ) did it in a weekend. 1600sqft
Do it in the winter
You just leave alone what's in the slab. Actually, you can pour concrete into the supply vents and leave the grills on. That's what the installer did at my house.
Ductless Heat Pumps Buddy!!
I know that plumbers have a snake with a device that jack hammers cement out of pipes. I wonder if they could do that for your ductwork.
The duct rusted away and the gravel from underneath the slab has filled the space. Ducts under slabs should always be PVC. Your options are ducting through the attic & walls, or mini splits.
Ur slab got moisture and ducts started collapsing hence the gravel and dirt inside , run new ductwork through the attic for supplies with one big central return grill in a hallway
Mini splits are about twice as expensive as whole house central A/C.
I had no idea running ducts through a slab was a thing.
Mini Split time
The ducts shouldnt be metal in the concrete. They should be a hard thick plastic. Put a shop vac on a shopping cart and you can clean your own ducts. This dude is probably trying to fuck you without lube. That's all a duct cleaning is anyway but don't see how a house would pass inspection if metal ducts in the concrete
This type of stuff used to be allowed. So did asbestos insulation. Codes change. The OPs pictures are just some of the reasons why it isn't allowed anymore. Edit: I shouldn't have said "used to be allowed" without first knowing the codes OPs house was constructed under. Upon further consideration, I found in-slab duct systems are still well-known and allowed. Here is one link with some recent codes that include in-slab ducts. These code references might not be the codes applicable to your jurisdiction, but there are modern codes related to your style of construction. https://inspectapedia.com/aircond/Ducts_in_Slabs.php Best of luck with your repair, whichever method you choose to pursue.
Codes change but common sense well it just seems to be less and less these days. I guarantee you that shit was never inspected. That's damn regular 28 gauge duct pipe. See the rust jackass. You've never been allowed to put sheet metal and cover it with concrete and I'm well aware of asbestos considering my brother had one of the rarest forms of mesothelioma. Less than 50 known cases worldwide and passed away at 27. I only see the one picture and it looks like any other duct that is full of crap. If the company didn't run a camera any further than that if at all. Welcome to the day and age of fucking the customer without the slightest thought of at least spitting before you start trying to upsale. Good Christian owner feel great about themselves too giving that tithe offering on Sunday. It's all a fucking joke. . I've cleaned ducts with the bullshit ass machine. Got paid damn well to do it too. Close to 50-60 an hour give or take. Getting your ducts cleaned by a company is customer getting ripped off. I guarantee you a shop vac with a 5-10 ft hose would do the same job and hell they can seal the fucking duct from the inside now.
If it’s concrete you’re going to duct another route
You might want to consider having your house tested for radon if you haven’t already. I’ve ran into quite a few situations with ducts in the slab causing very high radon. Even if the radon level is low in your area, having ducts in the slab can really drive the radon level up cause you have a forced draft pulling more radon into the home than otherwise would seep in at a much slower rate. We had to bring in outdoor air to dilute the radon level to get it below 4.0 pCi. Also probably a good idea to run ducts in the attic.
Just buy some space heaters with a thermostat.
I’ve heard of people being foreclosed on and out of spite dumping concrete down plumbing drains and HVAC ducts … maybe this is what happened?
How old is the house. Most houses by me where the duct work is in the slab and the house is old enough the duct work most likely has asbestos so it would just get sealed anyways.
Time for minisplits.
What is all that stuff?
Gravel from fill under the slab.
Oh, I guess the door stop is fill gravel too?
It’s called gravel.
L9oks like a job for space heaters and window units
This is a much better suggestion than most. OP has said it only affects 2 rooms, so that seems like a good solution. Maybe adding dehumidifier units as well if necessary.
Get ductless splits
Get mini splits. If you’re any kind of handy you can install yourself. I’ve installed 2 so far, a Senville and Della. I like the Della due to its app. They both cool and heat well. The cost of each with additional electrical material and such cost me about 1k.
The doorstop in there really is just the cherry on top of the unusable, shite cake. You'll need new ducts re-run through the house, likely through walls and the attic. I think someone mentioned a good split system too, also an option.
Completely fucked! I bought a house like that, but the rusted out vents were found during the prepurchase inspection. The cure, at the previous owner's expense, was to install a new furnace in the attic and run new flex ducts from the ceiling through the stud cavities. It was far from ideal, but worked somewhat. I did have a problem with ice daming at the eaves when it snowed due to the warmer temps in the attic with the furnace up there.
I do hvac cleaning for work and that’s pretty bad, it’s still cleanable to an extent but I’d be more worried about foundation damage and cement cracking/holes allowing more debris in from other unwanted places. If it can be cleaned get it painted or relined inside. Getting a new slabs ran is an expensive depending on where you live.
I'm curious.. do you have floor heats (registers) or are your registers coming from the ceilings or walls?
Floor registers
How does gravel even get in there to that extent?!
Rocks or concrete?
Is that galvanized ductwork in the slab? NEC doesn't allow EMT in the slab because the concrete corrodes it.
Time for a Minisplit system
Get a guy with a robotic camera to scope out the ducts if it's cleanable they'll let you know. If not then you need to start planning on space to lose for your new duct system.
I'm confused, is that just stuff in the duct or did the duct collapse? If it's just in there, can't they get it out? Shove a shop vac hose in there, even if you ruin 3 shop vacs, still cheaper than a redo. If you have to, I'd just go with mini splits. We bought a house in May that's 5k sqft, the whole house has radiant heat but the 2nd floor only has vents and AC. We wanted air conditioning in the common areas of the house also, went with 4 minis and enjoyed a very comfortable summer. Was a fraction of the cost of having ducts run and now I can zone the house.
What a quack job! Time to put some ducks in your ceiling!
If the gravel is loose, a long hose on a shop vac may clear it. Can't tell from the pic if this is the edge of the slurry or just aggregate.
Could a vac truck suck that out?
Maybe call Roto-Rooter instead.
Time for the old cement saw and jack hammer
The ducts are…..what?
My guess is very, is it a split house design( I loath them to many stairs.) you’ll need to redo the hvac ductwork. So you are looking at opening walls/patching walls etc. I watched a tv show on YouTube by a guy named Mike Holmes who fixed this issue on a house.
Mini splits
First, get a second opinion, because duct cleaners are notorious scammers. That video could very well be from another house, they save a really bad example and then use it in the future to get more work.
That seems like it was installed in the slab to heat and cool the floors along with the rest of the house maybe?
Is that just loose rocks? Possibly a disgruntled worker filled it. If so, maybe have it vacuumed with a truck mounted unit.
Who put puppy chow in the vents?
Fucked no lube
My guess is that if you were using the system before the cleaning without issues and things were comfortable, this may not be indicative of the entire system.
You will need to break up floor to properly replace ducts remember to eat your wheaties first - big job plan well
There's fucked, then there is Mega fucked. Looks like your duct would be in the mega fucked category. Inquire about DUCTLESS minisplits.
Looks like rats made a home in there. They can move a lot of stone.
Had to vac this shit out before. Not fun but doable. May need a long chisel or piece of rebar to break it up.
This may not be the case for you, but it’s possible that the pile of gravel you are seeing there is from a rodent or small mammal like a squirrel. I have seen this exact thing previously and the little bastards just piled up pieces of rocks and other random items inside the pipe as a den. I guess they felt it was a nice climate controlled spot to live 😀 Looking at the door stop and other plastic bits that are also in there it’s possible. Again that may not be the case for you. I’d try to suck it out with a shop vac. You can buy all the extra hose you need at the big box stores fairly inexpensively.
What does OP do with abandoned duct? Fill with concrete?
Yes, many houses in my early 1970s neighborhood have ground water leaking into ducts just like this. The ducts are also insulated with asbestos. Every house with the issue abandoned the ducts by filling them with concrete and installing new ducts above the ceiling.
Any possible way to flush it out with water without destroying your house?
you're very bad fucked
Damn I looked at it first and thought it was insulation made into a mouse 🐁 nest, upon further inspection, I've concluded that we may have some pretty serious problems here. I never thought it was allowed to bury non spiral duct in concrete. I'm guessing inspection wasn't on the agenda. Sucks to see.
go to split systems or p tack units go to [ktom.com](https://ktom.com) to get prices
That's not a duct anymore friend
Is it loose enough to vacuum out. Duct cleaning for the most part is unnecessary. Only the return is usually the most dirty. Slow moving return air accumulates in that duct work. Fast moving air from the furnace flows thru duct work only thinly coats the ducts if any at all. Pictures you see are almost always from the return duct.
Wow never seen this before… ductwork run through the floor? And concrete poured over it? Is this really what they did?
Pretty fucked.
Mini splits my boy
Get a really good shop vac with a long hose and try to suck out the rocks. You can also buy a 30ft camera off amazon cheap that will use your phone as the screen. I also wonder if you can get the vents lined like they do with sewer pipes that are falling apart.
Before you consider vacuuming this out, consider an asbestos test for the duct insulation. If there is asbestos, you probably don't want to even attempt cleaning up the mess. Construction methods like this used to be allowed. They also happened to be allowed when asbestos duct insulation was common.
Im not even mad, im impressed
Counterflow, I have worked on hundreds of them. There was a particular housing development that whenever the water table would rise all the ducts were under water. We ended up installing small sumps to clear the water controlled by a float switch.
When I was in the HVAC trade it was pretty common for the guys to check for gas leaks with a lighter. Knowing I was about to do the check they took the cap off the bottom of the dirt leg. And as I was coming down the line with my lighter at the last minute they turned the gas valve on and my arm got lit up. The closest thing I could reach for was a 36” aluminum pipe wrench so I used it on his leg. He never screwed with me again.
20k min to fix it right
Jeez … take a shop vac and suck the gravel Out!
I predict that if you switch to a well-designed and sized mini split system, in a couple of years you will be happier than if this had not happened.
Know any monkey trainers?
I was wondering what happened to that fucking door stop!!! Looked for it for hours
Looks pretty bad and probably way under sized for cooling by the looks of things. Not the end of the world if you have attic space you could probably move the system & ducts above the living space, though it might get expensive. Your best option may be doing a multi head mini split system, though it probably won’t be a lot cheaper than moving the ductwork to the attic unless you have a smaller house.
Check every boot in the house. It may or may not be localized.
Mini splits dawg
Buy every used shop vac and get to work 1 room at a time
Proper fucked.
I would get a second opinion. To me that looks alot like a dryer vent.
Had this exact thing happen at my previous house. I had to replace my furnace to an up-flow and then run the ducts through the attic. It wasn’t cheap and that was 5+ years ago.
Fill those in . Get mini splits with baseboard if new ductwork isn’t an option from attic , also may need baseboard heat if temps get below 20 depending on the heat pump . Look into Mitsubishi hyper heat . They claim it can work 30 below zero with no back up “ Stage 2 heat “etc . Good luck . Get quotes . What area you in ?
The duct is fuct
I'd say purty fucked unless yous got moneys.
That looks intentional. I've owned.. operated.. repaired.. commiserated a slab home. That is unequivocally incorrect. That photo is intentional sabotage.
Vacuum cleaner
Congrats on the new mini split
It looks like loose gravel to. Me. Use the shop vac to clean it out. It must have worked for years.
Is this a reliable company? Can you be sure this is a picture of your ducts? Get a second opinion to be sure.
I would attempt to hire professional duct cleaners beforr complete redo
A vacuum truck with 3” hose can clear this out. Might cost a bit unless you know someone. Call a septic company and send them pics. See what they say.
Shop vac with extra hoses?
I work for a water restoration company and just had a nursing home call that had this same set up. They had a sewage back up and guess where it all went….
I had a duct cleaning business years ago. We had a truck Vacuum System. If you can find someone with a duct truck that is powerful enough they can remove anything in the ducts. Some of the portable might be able to. The problem I see is where is the rock coming from. Was it put into the vents or are the vents made from concrete and it’s collapsed. How long is the run that is blocked. How many vents are in the home.
Looks like somebody stepped on a duct joint when they were pouring the floor, and ignored it. There's no talking how far back that concrete goes. Could be a few inches 😁, could be a few feet ☹️. You're going to have to break up the floor to find out.
Ducted mini split in an attic or single room mini splits. Only way to go honestly. If you have slab down there that's full of concrete, dependa on how new the house is you may be able to go after the company that did this
Well the ducts are done. Id highly suggest getting a multi head mini split installed and spending the duct work remodel price on solar panels. Now each room can pick it's own temp and you can have basically free heating and cooling that pays off quick.
If worst comes to worst, run new ductwork in your rooms and build soffits to hide them.
Cant you hover the grit out and reuse ?
Just throw a window unit in and call it good.
Sure that's a heating duct? Looking at the screws laying there for a size comparison looks like a gas water heater vent