Author Topic: Director's Advisory FS-065-05 - Interior Type-B Vents and Metal lined chimneys  (Read 2135 times)

Offline Admin

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Vent Sizing and Resizing for Interior Type-B Vents and Metal lined chimneys.

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Clause (8.13.1) - A vent or chimney serving a single appliance shall provide effective venting and shall be sized
(a) so that its effective area is not less than that of the draft-control device outlet or the flue outlet; or
(b) in accordance with good engineering practice, such as by the use of
  (i) Table C.1, C.2, C.5, or C.6 of Annex C for a draft-hood-equipped or a fan-assisted Category I appliance; or
  (ii) engineered venting tables acceptable to the authority having jurisdiction.

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Annex C (C.2.2) - The vent tables included in this Annex apply to vents and chimneys internal to the structure below the roof line. Exterior chimneys or vents not enclosed by the structure or a chase below the roof line can experience continuous condensation, depending on locality. A chimney with one or more sides exposed to the outside of the structure shall be considered to be an exterior chimney. A Type B vent or a certified chimney lining system passing through an unused masonry chimney flue shall not be considered to be exposed to the outdoors. The DP column shall be used to determine the capacity of a venting system within a building constructed in accordance with Clause 8.2.1.

Download Director's Advisory FS-065-05 - Here

Offline Hgye

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Is this Director's Advisory still valid?

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Yes, it's just to clarify Clause 8.13.1.

What's interesting in the B149.1-10 Clause 8.13.1 said,

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Clause 8.13.1 - A vent or a chimney serving a single appliance shall provide effective venting and shall be sized
(a) so that its effective area is not less than that of the draft-control device outlet or the flue outlet; or
(b) in accordance with good engineering practice, such as by the use of
(i) Table C.1, C.2, C.5, or C.6 of Annex C for a draft-hood-equipped or a fan-assisted Category I appliance; or
(ii) engineered venting tables acceptable to the authority having jurisdiction.

The B149.1-10 CAD FS-212-14 substituted it to say,

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Clause 8.13.1 - A vent or a chimney serving a single appliance shall provide effective venting and shall be sized;
(a) for a single appliance with draft hood the effective area of the vent connector or and chimney flue is not less than the area of draft hood outlet, or greater than seven times the draft hood outlet area; or
(b) in accordance with good engineering practice, such as by the use of
(i) Table C.1, C.2, C.5, or C.6 of Annex C for a draft-hood-equipped or a fan-assisted Category I appliance, or
(ii) engineering methods acceptable to the authority having jurisdiction;

The B149.1-15, which takes effect July 1, 2017 says,

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Clause 8.13.1 - A vent or a chimney serving a single appliance shall provide effective venting and shall be sized
(a) so that its effective area is not less than that of the draft-control device outlet or the flue outlet; or
(b) in accordance with good engineering practice, such as by the use of
(i) Table C.1, C.2, C.5, or C.6 of Annex C for a draft-hood-equipped or a fan-assisted Category I appliance; or
(ii) engineered venting tables acceptable to the authority having jurisdiction.

CAD FS-225-17 does not substitute Clause 8.13.1 or Clause 8.13.2.