Thread: Supply venting into garage

This heat supply vent is supplying heat to water heater which is located in a closet in the garage. Does anyone know if a supply duct is allowed in a closet eventhough it is still in the garage. Also, is the supply duct allowed to vent directly onto the water heater flue.

Thanks

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Stupid idea, but I see there is a weather stripped door which moves the heater inside the conditioned envelope. This may get around the prohibition against duct openings in a garage.
I'll bet there is enough other stuff wrong to call out a professional if you look closely.

Do you have an establishing shot (further away)?

Call the city. The door may have to be fire rated. Otherwise Park City told me the duct has to have a spring loader damper and by a mim guage metal, then it can be located within the garage.

As long as that closet is separated from the garage by a fire break it should not be a problem. I would add a diffuser to the heat duct.

I do believe this is a gas water heater, and I realize this is a HVAC supply (air blowing in).

But if you have a leak, could the trunk line fill with carbon monoxide while the unit is not running and then be force into the house when it turns on, or it is the time of year when the HVAC is not running and the carbon monoxide just drifts into the house, or the room reaches negative pressure and the supply begins to draw.

This is just a thought with nothing to back it up, even if it is legal it doesn't seem like a good idea.

If the door is sealed where is the makeup air to the water heater coming from?

In Chicago makeup air needs to come from above and below due to circulation issues that also tie in with the 1 sq " per 1,000 BTU rule..

As far as the rest goes, how is it any different from having a heater in the same utility closet as the Furnace ?

Good morning: In the province of Ontario the single wall vent through the hole in the wall going into the B vent does not have sufficent clearance to combustibles(would require 6" up here & our provincial authority does not accept that the paper on drywall is non-combustible.Don't know if its the same in your area.

Jim, Could you supply code reference for prohibition against duct openings in garage. I thought it was for a return air duct which runs thru garage to service areas in the house. Thanks.

Ryan, Are you sure that isn't fresh outside air for combustion?

Originally Posted by Tom Rees

Jim, Could you supply code reference for prohibition against duct openings in garage. I thought it was for a return air duct which runs thru garage to service areas in the house. Thanks.

R309.1.1 Duct penetration. Ducts in the garage and ducts penetrating the walls or ceilings separating the dwelling from the garage shall be constructed of a minimum No. 26 gage sheet steel or other approved material and shall have no openings into the garage.

Something to watch out for when you see the model homes being sold when they close out a subdivision. Lots of times they have converted the garage to a sales or sample showroom and dropped a/c vents through the ceiling.

In this instance it appears the utility closet has been separated from the garage but it still bears looking closer to make sure the separation between the garage and house have not been compromised.

I still think it is a dumb idea to condition a small closet like that.

Condensation/venting nightmare, during the non-heating A/C season too.

The single wall from the furnace and the WH no required clearances there, See lots of exposed crimping and no screws on the SW - not good. Wonder about height of furnace and draft with all those offsets. Water lines, cord & exposed spun insulation also not good.

It's wrong and should be closed up. The owner needs to add some electric heat to keep the plumbing from freezing. ( assuming that was why it was cut in.) But if that's a functioning water heater the closet it would never freeze to being with. even in Park City

You need to figure out why is was added and address that problem too.


Edit. Let's just say it's possible to have the HVAC off and the water heater running. The combustion air gets block off for some reason and the WH starts making tons of CO which as access right into the house duct work.
Where is the combustion air for the water heater coming from? Where is the WH flue exhaust going out? In your area snow blocking these vents is a concern. Does looks like they sealed off the garage to kept the car exhaust out.

9NEWS.com | Denver | Colorado's Online News Leader | Investigators look for CO detector in home where family died

Thanks for the code Jim.

You have some major concerns with the venting. It appears you have B-vent improperly penetrating a combustible wall alongside single walled vent connector that is improperly supported and probably undersized infringing on the 6" clearance to combustibles.

If you have a supply pumping air under pressure into a very confined CAZ, it can severely distort the flames causing flame rollout, sooting, CO, etc. Need a pro to inspect and perform combustion analysis. WH's not approved for venting in a positive pressure environment. You have the potential for a "curtain effect" at that draft hood, which can effectively block the flow of flue gases dumping heat and CO into the closet.

A warm supply is not recognized as a source of MUA.

Bob

Originally Posted by Tom Rees

Ryan, Are you sure that isn't fresh outside air for combustion?

Thats what I was thinking.

I cannot make it out from the photo's. It appears that there is insulation on top of the water heater blocking the draft hood?

If this IS a supply, then where is the return? You need a return to balance the system yet you cannot pull a return from a garage.

Hard to tell as arm chair Q'backs but so much seems wrong with this setup.

Originally Posted by Bob Harper

If this IS a supply, then where is the return? You need a return to balance the system yet you cannot pull a return from a garage.

Hard to tell as arm chair Q'backs but so much seems wrong with this setup.

Or a mechanical closet with gas fired units.

Anyway as the OP has been told, there are so many items in question that it is time for a qualified tech to eval and repair.

I noticed a couple posters said he has to figure out this and that. The only thing he has to figure out is that there are many items wrong and state them and defer to a qualified third party.

Some one had a few good ideas (bad ideas ?) for the wrong application that should have never been done. After everything else is fixed someone mentioned electric heat. A very small electric heat strip might work depending on the rest of the situation in that closet. Ventilation/make up air, still remains an issue that will have to be addressed no matter what else is corrected.

If the closet has a door to the garage and no door to the house, it's part of the garage. Adding a fire door or weather-stripping will not suffice.

In part, M1307.3 of the 2006 IRC mechanical code states the following-

"...For the purpose of this section, rooms or spaces that are not part of the living space of a dwelling unit and that communicate with a private garage through openings shall be considered to be part of the garage."