The Ontario Building Code | Ducts

9.32.3.10. Ducts

(1) ventilation ducts shall conform to the requirements of Part 6 for supply ducts, except that exhaust ducts that serve only a bathroom or water closet room may be of combustiblematerial provided the duct is reasonably airtight and constructed of a material impervious to water.

(2) Exhaust ducts shall not discharge into heated or unheated enclosed spaces.

(3) Where an exhaust duct passes through or is adjacent to unheated space, the duct shall be insulated to not less than RSI 0.5.

(4) Where a duct carrying outdoorref ="http://thehandyforce.com/doors/" title ="Toronto Door installer">door air that is not tempered or not mixed with indoor air passes through heated space, it shall be insulated to not less than RSI 0.5 except that, where such a duct is exposed in the heated space for more than 3 m of length in the heated space, it shall be,

(a) insulated to not less than the values listed in Table 9.32.3.10.A., and

(b) provided with a vapour barrier.

Table 9.32.3.10.A.
insulationhttp://thehandyforce.com/insulation/" title ="Toronto home insulation">insulation of Ducts Carrying outdoorref ="http://thehandyforce.com/doors/" title ="Toronto Door installer">door Air

Forming Part of Sentence 9.32.3.10.(4)

Item

Column 1

Outside Winter design Temperature as per MMAH Supplementary Standard SB-1, "Climatic and Seismic Data"(1), °C

Column 2

Minimum Thermal Resistance, RSI

1.

–7 to –11

0.5

2.

–12 to –17

0.9

3.

–18 to –24

1.2

4.

–25 to –29

1.4

5.

–30 to –34

1.8

6.

–35 and colder

2.1

Notes to Table 9.32.3.10.A.:

(1) The outside winter design temperatures shall be those listed for the January 2.5 percent values.

(5) A kitchen exhaust duct not equipped with a filter at the inlet end shall be designed and installed so that the entire duct can be cleaned.

(6) Ductwork for cooking appliance exhaust fans shall,

(a) be of noncombustible, corrosion-resistant material, and

(b) lead directly to the outdoorref ="http://thehandyforce.com/doors/" title ="Toronto Door installer">doors without connection to other exhaust fans or ducts.

(7) Ductwork for cooking appliance exhaust fans shall be equipped with a grease filter at the intake.

(8) All ductwork shall be permanently supported or clipped to prevent sagging, excessive movement and vibration.

(9) All ducting connected to supply and exhaust fans shall be constructed so as to inhibit air leakage at joints.

(10) Where rectangular duct is used in place of round duct, it shall be selected according to Table 9.32.3.10.B.

Table 9.32.3.10.B.
Equivalent Duct Sizes

Forming Part of Sentence 9.32.3.10.(10)

Item

Column 1

Column 2

Column 3

Column 4

Column 5

Required Round Duct Size, mm

Permitted Equivalent Rectangular Duct Size, mm

Stack Duct

100 mm Depth

125 mm Depth

150 mm Depth

1.

75

82 × 250

57 × 100

2.

100

82 × 250

89 × 100

75 × 125

75 × 150

3.

125

82 × 250

125 × 100

100 × 125

89 × 150

4.

150

82 × 300

200 × 100

150 × 125

125 × 150

5.

175

82 × 350

275 × 100

200 × 125

175 × 150

6.

More than 175

Part 6 design

Part 6 design

Part 6 design

Part 6 design