B149.1 OFC ITSM 17-009 Clarification of Appliance Vent Termination

[rkhan]

Hello all Hvac Installers,

There has been a terrible misinterpretation of the Propane and Gas Appliance Vent Termination Rule that clearly states:

B149.1 Code Allows an appliance vent to terminate directly over the centre-line of a regulator providing that the appliance vent terminates at a height of 15 feet or more above the meter/regulator assembly.

It then goes on to say:

However, moisture in flue products may condense at the outlet of the vent in cold weather and there is potential for this condensation to drip down onto and interfere with a regulator installed directly below.

So the Proposed Solution would be:

Therefore, in Manitoba an appliance vent must Never terminate within 3 feet horizontally of the vertical centre of the regulator vent outlet.

There is then an image of the gas regulator assembly with various heights below 15 feet and horizontal distances within 3 feet with a diagonal line across it indicating the Vent Termination should NOT be installed anything lower than 15 feet or within 3 feet from the Gas meter/regulator assembly vertical centre-line of the regulator vent outlet.

Somehow this regulation seems to be misinterpreted by the local Gas Suppliers and I am finding that in congested areas there are High Efficiency Fuel (Condenser Furnace) Vents being installed at a 3 foot height above a walkway in between two adjacent single detached houses. This is causing much ice build up with dangerous Carbonic Acid Formations on the walkway and stairway leading up to our patio. This liquid Carbon Monoxide will not be detected by their Carbon Monoxide detectors as it is now in a liquid form, it is condensed to form Carbonic Acid so they should be using Carbonic Acid Detectors to determine if the walkway is contaminated with this acid. The acid is strong enough to eat through metal so it definitely will weaken any corner support beams of the adjacent house causing damage to any residing properties. There is a 3 feet distance between the Vent Termination opening and my sidewall.

B149.1 17-009 Clearly states that the correct placement of a Furnace Vent should be more than 15 feet in height and more than 3 feet to the right or to the left of the gas regulator assembly unit.

The height of 15 feet or higher is not being considered during installation.

[Admin]

One option is to extend the regulator vent outlet away so that any vents are not within that space.

[NoDIY]

One option is to extend the regulator vent outlet away so that any vents are not within that space.

Ask and pay the utility to do that. They are the only ones that can vent away those regulators

[Byron]

One option is to extend the regulator vent outlet away so that any vents are not within that space.

I've gone over this with my local TSSA inspector and this is not a suitable option as it states centerline of the regulator vent outlet not the regulator vent termination, so by moving the point of termination you haven't solved the issue.

[Admin]

The regulator vent outlet is the termination.  Extending the regulator's vent has always been an acceptable method with any natural gas or propane distributor I have dealt with.  That's interesting that a TSSA inspector interprets it that way.  Thanks for the heads up!

The concern should only be with the regulator vent outlet.  At least according to the B149.1-20 Handbook.

Distances from meter/regulator sets are intended to prevent water vapour in flue gases from condensing out on service regulator vent outlets where it can then freeze and plug the outlet.

[Porcupinepuffer]

I've had no issues with extending the outlet in situations where clearance to electrical was a problem, but that was never given for where moisture can cause ice buildup over a regulator.

[Admin]

I think the intent of Clause 8.14.8(e) is to prevent the regulator vent outlet from being blocked by ice, but I do understand the regulator itself can freeze.  We can also vent below a regulator (3 feet away) to circumvent this 15' rule.