BCAB #1920

October 19, 2023

Re:  Kitchen Ventilation in a Home with High Energy Efficiency

Project Description

The project consists of a new single family home constructed to be highly energy efficient and employing a high degree of air tightness.  A heat recovery ventilation system is installed; no gas or propane appliances are installed.  The kitchen has a hood fan with closed carbon filtration for odor and humidity control; there is no kitchen vent to the exterior.

Applicable Code requirements (BCBC 2018)

Subclause 9.32.3.6.(1)(a), Division B, 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, [. . .]

Sentences 9.32.3.8.(2) and (7), Division B, Air Ducts
2) Exhaust ducts shall discharge to the outdoors.
7) Where a kitchen exhaust fan grille is installed within 1.2 m horizontally of a cooktop, the exhaust fan duct shall
a) be constructed of a material that is noncombustible, corrosion-resistant, and cleanable, and
b) be equipped with a grease filter at the intake end.

Decision being appealed (Local Authority’s position)

The kitchen hood fan does not satisfy:

• the kitchen exhaust fan requirements outlined in Subclause 9.32.3.6.(1)(a), Division B,
• the exterior discharge requirements outlined in Sentence 9.32.3.8.(2), Division B,
• the exhaust fan duct requirements outlined in Sentence 9.32.3.8.(7), Division B.

Appellant's position

Provision of a kitchen exhaust penetration would have a negative impact on the air tightness of the building leading to reduced efficiency of the mechanical system.  The hood fan filtration system provides odor and humidity control and should be sufficient.

Appeal Board Decision #1920

The Board confirms the decision of the local authority.

It is the determination of the Board that a recirculating hood van does not satisfy the Code requirements.

Reason for decision

The Code provides prescriptive requirements to address the need for odor, particulate, and humidity control.  A recirculating hood fan does not exhaust.

Don Pedde
Chair, Building Code Appeal Board