9.32.2. Non-Heating-Season Ventilation

9.32.2. Non-Heating-Season Ventilation
9.32.2.1. Required Ventilation
  1. The non-heating-season ventilation required by Clause 9.32.1.2.(1)(a) shall be supplied by
    1. natural ventilation in accordance with Article 9.32.2.2., or
    2. a mechanical ventilation system in accordance with Article 9.32.2.3.
9.32.2.2. Non-Heating-Season Natural Ventilation
  1. 1) The unobstructed openable ventilation area to the outdoors for rooms and spaces in residential buildings ventilated by natural means shall conform to Table 9.32.2.2.

    Table 9.32.2.2.
    Natural Ventilation Area
    Forming Part of Sentence 9.32.2.2.(1)

    Table 9.32.2.2. Natural Ventilation Area

  2. Where a vestibule opens directly off a living or dining room within a dwelling unit, ventilation to the outdoors for such rooms may be through the vestibule.
  3. Openings for natural ventilation other than windows shall provide protection from the weather and insects.
  4. Screening shall be of corrosion-resistant material.
9.32.2.3. Non-Heating-Season Mechanical Ventilation
  1. Where a habitable room or space is not provided with natural ventilation as described in Article 9.32.2.2. and is mechanically cooled, its non-heating-season mechanical ventilation system shall
    1. have the capacity to exhaust air from inside the room or space, or to introduce outdoor air into that room or space, at a rate conforming with Table 9.32.2.3., or
    2. comply with Subsection 9.32.3.
  2. In applying Clause (1)(a),
    1. at least one bedroom in each dwelling unit shall be designated as the master bedroom,
    2. air change rates for any combined living/dining or family/dining space shall be determined as if the spaces were individual rooms,
    3. where a basement incorporates rooms of the types designated in Table 9.32.2.3., the assigned air change rate for each room shall be as specified for those types of rooms,
    4. basement areas used for other purposes that exceed 2/3 of the total basement floor area shall be assigned an air change rate of 10 L/s,
    5. basement areas used for other purposes that are 2/3 of the total basement floor area or less shall be assigned an air change rate of 5 L/s, and
    6. other habitable rooms, other than spaces intended solely for access, egress, storage, or service equipment, shall be assigned an air change rate of 5 L/s.


      Table 9.32.2.3.
      Air Change Rate

      Forming Part of Clause 9.32.2.3.(1)(a)

      Table 9.32.2.3. Air Change Rate

  3. Where a habitable room or space is not provided with natural ventilation as described in Article 9.32.2.2. and is not mechanically cooled, the non-heating-season mechanical ventilation system shall have the capacity to exhaust indoor air from the room or space or to introduce outdoor air to that room or space at a rate of one air change per hour.
  4. A non-heating-season mechanical ventilation system shall be designed and installed in conformance with good practice such as that described in the ASHRAE Handbooks and Standards, the HRAI Digest, the Hydronics Institute Manuals and the SMACNA manuals.