March 14, 2023
The subject is the required kitchen exhaust for the ventilation system requirements for a highly energy efficient house. The proposed design incorporates a Heat Recovery Ventilation Unit (HRV) to provide the required exhaust from the kitchen area.
Applicable Code requirements: (BCBC 2018)
9.32.3.6. Kitchen and Bathroom Exhaust Fans
1) An exhaust fan that provides at least the air-flow rate specified in Table 9.32.3.6. shall be installed in
a) every kitchen, and
b) every bathroom or water-closet room, unless the bathroom or water-closet room is served by the principal ventilation system exhaust fan that complies with Article 9.32.3.5.
Decision being appealed: (local authority’s position)
The local authority contends the required kitchen exhaust fan must vent independently from the Heat Recovery Ventilator, and directly to the outdoors.
Appellant's position:
The appellant contends the oversized HRV unit at high speed will comply with and provide the required intermittent ventilation rate for a kitchen area as specified in Table 9.32.3.6.
Appeal Board decision #1906:
Provided the exhaust provisions of the HRV ventilation unit are capable of providing the minimum exhaust requirements of 47 L/s for the kitchen area, with control for kitchen area spot ventilation at this rate, it is the determination of the Board the required kitchen exhaust may incorporate the exhaust provisions of the HRV unit. This decision is premised on the basis that the HRV exhaust system is compatible with kitchen exhaust that may contain grease and vapour particulates.
Reason for decision:
The Board does not consider the N/A entry in Table 9.32.3.6. for Kitchen-Continuous to mean “not permitted”, but rather “not applicable.”
Lyle Kuhnert
Chair, Building Code Appeal Board