AC duct in garage ceiling

The municipal inspector who issues Certificates of Occupancy when ownership changes or apartments get new tenants, failed me because he saw a "vent" in the garage ceiling. The potential problem is that any carbon monoxide in the garage can be sucked up by the vent when the heat or a/c is running and be distributed throughout the house. He wants me to cover it with metal or sheetrock and caulk around the edges.
Problem is, that it is really a supply register. When I looked in the attic, I could clearly see that the duct supplying it came directly from the plenum (just above the evaporator) that feeds the other ducts to the rest of the house.
I removed the register and found that someone had taped its openings shut, so air couldn't flow either way through it. I sent photos to the inspector of the register showing how it was taped shut. I also taped a small piece of facial tissue to the ceiling and turned on the a/c. It fluttered in the incoming airstream, and was not sucked upwards as it would be if this were a return.
I wanted to just return the taped-shut housing the way it was. But the inspector is being hard-assed. He doesn't want to see anything - supply or return - in the ceiling. I do NOT think he's looking for me to slip him a few bucks.
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Rebel1 wrote:

Hi. To me it is not only CO risk, it is fire hazard as well. His demand has valid reason. Piece of sheet metal and some screws will satisfy him. Tape is not fire proof. Not a big deal.
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Is that a question? Why not just do what he says? If you look at it from his point of view, he doesn't want to go by your say-so. He wants to see it clearly covered. So just cover it. It's an easy job. Just go to HD and get one of those broken drywall scrap pieces. (If you want to use it for heat later you can always uncover it again. It does seem like a rather extreme, letter-of-the-law attitude on his part. But he could be held responsible for a letter-of-the-law infraction.)
| The municipal inspector who issues Certificates of Occupancy when | ownership changes or apartments get new tenants, failed me because he | saw a "vent" in the garage ceiling. The potential problem is that any | carbon monoxide in the garage can be sucked up by the vent when the heat | or a/c is running and be distributed throughout the house. He wants me | to cover it with metal or sheetrock and caulk around the edges. | | Problem is, that it is really a supply register. When I looked in the | attic, I could clearly see that the duct supplying it came directly from | the plenum (just above the evaporator) that feeds the other ducts to the | rest of the house. | | I removed the register and found that someone had taped its openings | shut, so air couldn't flow either way through it. I sent photos to the | inspector of the register showing how it was taped shut. I also taped a | small piece of facial tissue to the ceiling and turned on the a/c. It | fluttered in the incoming airstream, and was not sucked upwards as it | would be if this were a return. | | I wanted to just return the taped-shut housing the way it was. But the | inspector is being hard-assed. He doesn't want to see anything - supply | or return - in the ceiling. I do NOT think he's looking for me to slip | him a few bucks. |
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On Thursday, August 7, 2014 1:14:37 PM UTC-4, Mayayana wrote:

I don't think the inspector is being hard-assed, he's just following the code. AFAIK, neither a supply nor a return is allowed into a garage space. Think about what happens when the system is off. You have an easy path for CO into the house. Depending on which way the wind is blowing, pressures, etc, CO could go into the house.
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On Thursday, August 7, 2014 1:15:33 PM UTC-4, trader_4 wrote:

Forgot to add, if you're buying this place, for me, this would be a big red flag and an indication that you need to do a careful inspection for other problems. How it got built and inspected to begin with, who knows. Could be that some owner added it after.
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On 8/7/2014 1:41 PM, trader_4 wrote:

Last week the inspector hired by the guy buying my house gave a very thorough inspection, and said nothing about this. I mentioned to the municipal inspector that this house has changes ownership seven times since being built in 1967 and was never cited for this reason. He replied that this became a item to check only since 1996. I bought the house in 2000, so it should have been flagged at least once before.
The concern about CO seems rather theoretical. How many cars are left running in garages for extended periods? When the heat/AC is running? With today's stringent emissions, I don't think very much CO is generated to begin with. Besides, the house has two CO/smoke detectors.
Thanks to all for raising other possible concerns that I hadn't considered that were not mentioned by the inspector.
R1
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On Thursday, August 7, 2014 2:16:24 PM UTC-4, Rebel1 wrote:

Not unusual. Many of the "home inspectors" miss a lot more than that because they don't know what they are doing.
I mentioned to the

That sounds about right.
I bought the

The HVAC doesn't have to be running for fumes to go from the garage to the living space via the duct. It also would be highly dependent on the layout of the house. If a bedroom were close by on the duct layout, it would get there a lot easier and be worse than if the bedrooms were on the opposite end.

I agree it's questionable as to how big of a threat it is. If you ever watch the Mike Holmes TV show from Canada, he finds this and goes ballistic. CO! CO! I agree, cars typically are only started up with the doors open and then they quickly leave. And, as you point out, cars today emit a tiny fraction of the CO they once did, assuming they are working properly. Another aspect is that unless the area around the duct opening is properly sealed with fire resistant caulk, it's a potential path for fire into the house. Code requires a fire rated door between the house and garage for the same reason. Overall, it's probably made out to be much worse of a threat than it really is.
On another note, what is one register going into the garage suppose to do exactly? I would think it's pretty much a waste, not enough heat to make a big difference anyway?
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trader_4 wrote:

Hi, Also it can act like a chimney if ever there was fire breaking out in the garage(who can say it'll never happen?) Maybe OP is harda*!ed?
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On 08/07/2014 12:15 PM, trader_4 wrote: ...

Suppose is possible; hadn't heard it was code. The TN house had an outlet from the furnace supply a little heat into the garage and I never thought anything of it...only attached garage ever had.
--


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dpb wrote:

Hi, In our city, garage supposes to have separate heater within properly installed. Not allowed to be tied into house HVAC system.
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On 08/07/2014 1:17 PM, Tony Hwang wrote:

...

...

Probably wasn't "legal" there at the time, either, it was in a County area outside zoning and the builder was a renegade heavy-equipment operator who thought he'd make "the big bucks" as a contractor during a boom in Oak Ridge hiring when we moved there in '78.
--


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yet another example of a code being written without a cost/benefit analysis.
In snow country, our friend's house has a furnace outlet into the basement garage. Without it I bet pipes would freeze.
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Pico Rico wrote:

Still it is not proper and they could put a direct vent heater in garage area. Would you want a basement with bedrooms without any windows to exit in case of a fire? Same difference and a lot of homes have them but is not a good situation. Just cover it and let the new owner uncover if he wants and understands the risks. JAS
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not at all the "same difference".
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Pico Rico wrote:

Yes--We are talking about the safety of the occupants of the home.
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I know of a home where the car parked in the garage caught on fire and destroyed the homre.
baierl automotive group was run by bill baierl, he left his car running in the garage, he and his wife died from CO2 poisioning.
We got co2 poisioning from a blocked water heater flue. we could of died.
just so happened a buddy stopped by, a volunteer fireman...
he recognized the symptoms, when he got ill too.
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In typed:

Since you posted later that you are selling the property, and just need the C of O to sell it, it seems like a no-brainer to just do what the inspector said that he is requiring. And, as someone wrote, if the new owners want to change it back later, that's on them.
You showing the inspector that the duct is taped closed, and also showing him that with the a/c on the tissue flutters (which means that the duct is not completely taped closed), seems like contradictory information -- it is either sealed off or it isn't. He wants it properly sealed off and that's exactly what I would do.
I did not think of the reasoning that others posted here about how even a supply duct in a garage could result in car exhaust fumes back-flowing into the whole HVAC system -- especially when the system fan is not on. That makes sense and obviously that is why the inspector does not want to see an open HVAC vent in the garage.
I bought a home that has an attached garage that was partially unfinished -- the exterior walls were open walls with no insulation. I finished the garage by adding insulation to the exterior walls and closing the walls with new sheetrock. One thing that I noticed was that even though there is a closed soffit in the garage that contains a supply duct to and room on the interior of the home, there was no supply duct or vent to allow the garage to be heated. I have been thinking of adding supply vent to the garage from that supply duct, but now I know that would be improper and could cause a serious problem. So, your experience and the citation form the inspector taught me something that I did not know before.
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If you want to heat or condition garage space the garage space MUST be heated or conditioned with it's own unit, with no air exchange between the two spaces. Some places go so far as to prohibit a door between the garage and living space. I think THAT is going too far - why have an "attached" garage if you have to go outside to access it?
My dream house is a small 2 bedroom bungalow with a double garage, 1 1/2 cars deep minimum, with basement under the garage as well as the house - walk out under the house, and single garage door under the garage - with the garage high enough to handle a 2 post hoist on one side. Yes, the garage would be as big as the house!!!
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wrote:

Exactly. "When he got ill too."
That's the advantage of this duct in the garage. When the people in the house start feeling CO sick, they'll know someone is in the garage trying to kill himself, and they can stop him.
Okay, just kidding.
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Where I live, there cannot be any connection between the garage and house except for a fireproof door and 5/8 inch sheetrock on the walls and ceiling of the garage.
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