Warning This information has been archived because it is outdated and no longer relevant.

Archived Content

Information identified as archived on the Web is for reference, research or recordkeeping purposes. It has not been altered or updated after the date of archiving. Web pages that are archived on the Web are not subject to the Government of Canada Web Standards. As per the Communications Policy of the Government of Canada, you can request alternate formats on the "Contact Us" page.

9.32.3.8.(5)
ApplicationIntent
OH1OS1OS3
ObjectiveOH1 Indoor Conditions
Attribution
[F53-OH1.1]
Application
Application 1: 
Supply fans rated to deliver outdoor makeup air, where outdoor makeup air is not tempered upstream of the supply fan, in dwelling units that:
This applies to self-contained heating-season mechanical ventilation systems serving single dwelling units with 5 or fewer bedrooms that are supplied with electrical power and a heating system, in buildings to which:
  • Part 9 applies [see Sentence 1.3.3.3.(1) of Division A for application of Part 9], or
  • Part 6 applies [see Sentence 1.3.3.2.(1) of Division A for application of Part 6 and Sentence 6.2.2.1.(3)].
Exceptions: 
except as stated in:
  • Sentence 9.32.3.8.(2), which exempts the principal ventilation fan operating at a rate not greater than the maximum permitted in Table 9.32.3.3. from the requirements in Article 9.32.3.8. that address the supply of outdoor makeup air to mechanical air-exhausting devices,
  • Sentence 9.32.3.8.(8), which exempts dwelling units with solid-fuel-burning appliances from the requirement for outdoor makeup air when all other fuel-fired appliances are direct-vented or mechanically vented and soil gas is not a concern,
  • Sentence 9.32.3.8.(9), which exempts dwelling units from the requirement for outdoor makeup air, where a test performed in accordance with the procedures in CAN/CGSB-51.71 indicates that the maximum depressurization levels will be within acceptable limits, and
  • Sentence 9.32.3.1.(1), which applies to heating-season mechanical ventilation systems designed to comply with CAN/CSA-F326-M.
Top of Page
Intent
Intent 1: 
To limit the probability of the premature failure of supply fans, which could lead to excessive negative pressure.
This is to limit the probability of:
  • the ingress of soil gases (such as methane and radon),
  • the spillage of combustion products from fuel-burning appliances that are susceptible to spillage, or
  • moisture ingress from the ground, which could lead to the generation of pollutants from biological growth or from materials that become unstable on wetting.
This is to limit the probability of negative effects on the air quality of indoor spaces, which could lead to harm to persons.
Intent 2: 
To exempt supply fans from the requirement to be approved to handle untempered outdoor air, in situations where the outdoor makeup air is tempered before it reaches the supply fan.
Top of Page