The Ontario Building Code | Ventilation Systems Not Coupled with Forced Air Heating Systems
9.32.3.7. ventilation Systems Not Coupled with Forced Air Heating Systems
(1) This Article applies to a mechanical ventilation system in a dwelling unit that,
(a) does not contain a forced air heating system, or
(b) contains a forced air heating system which is not used for circulation of the ventilation air.
(2) The mechanical ventilation system shall introduce air to and circulate air throughout the dwelling unit in compliance with this Article.
(3) The mechanical system in this Article shall include a heat recovery ventilator installed in accordance with Article 9.32.3.11.
(4) outdoorref ="http://thehandyforce.com/doors/" title ="Toronto Door installer">door air shall be distributed by a ductwork system from the heat recovery ventilator required in Sentence (3) to each bedroom, to any storeywithout a bedroom and, if there is no storeywithout a bedroom, to the principal living area.
(5) Asupply duct from the outdoorref ="http://thehandyforce.com/doors/" title ="Toronto Door installer">doors to the heat recovery ventilator required in Sentence (3) and a main distribution trunk duct shall be provided and shall be sized according to Part 6, except that the supply duct and the main distribution trunk duct may be sized according to Table 9.32.3.7.A. where,
(a) the total duct length from the outdoorref ="http://thehandyforce.com/doors/" title ="Toronto Door installer">door hood to any supply register does not exceed 21 m, and
(b) the total number of fittings does not exceed 8.
Table 9.32.3.7.A.
Minimum outdoorref ="http://thehandyforce.com/doors/" title ="Toronto Door installer">door Air Supply and Main Trunk Duct Sizes
Forming Part of Sentence 9.32.3.7.(5)
| Item | Column 1 Number of Bedrooms in Dwelling Unit | Column 2 Minimum outdoorref ="http://thehandyforce.com/doors/" title ="Toronto Door installer">door Air Supply and Main Distribution Trunk Duct Diameter, mm |
| 1. | 1 | 150 |
| 2. | 2 | 150 |
| 3. | 3 | 175 |
| 4. | 4 | 175 |
| 5. | 5 | 175 |
| 6. | More than 5 | System must comply with Sentence 6.2.1.1.(1) |
(6) The outside air supply duct required by Sentence (5) shall not be considered to provide combustion and/or dilution air to fuel-burning appliances.
(7) Branchsupply ducts leading from the main distribution trunk duct required by Sentence (5) to the rooms to which outdoorref ="http://thehandyforce.com/doors/" title ="Toronto Door installer">door air is to be distributed shall be provided and shall be sized according to Part 6, except that the branch supply ducts may be sized according to Table 9.32.3.7.B. where,
(a) the total duct length from the outdoorref ="http://thehandyforce.com/doors/" title ="Toronto Door installer">door hood to any supply register does not exceed 21 m, and
(b) the total number of fittings does not exceed 8.
Table 9.32.3.7.B.
Minimum Branch Supply Duct Sizes
Forming Part of Sentence 9.32.3.7.(7)
| Item | Column 1 | Column 2 | Column 3 |
|
| Room, Space or Storey Served | Minimum Branch Supply Duct Diameter, mm | |
|
| 1 and 2 Bedroom Dwelling Units | 3, 4 and 5 Bedroom Dwelling Units | |
| 1. | Master bedroom | 100 | 100 |
| 2. | Other bedrooms | 75 | 75 |
| 3. | Storey with no bedrooms or living area | 75 | 100 |
(8) In applying Sentence (7), where the dwelling unit has more than 5 bedrooms, ducting shall be sized according to Part 6.
(9) All branch supply ducts that are not fitted with diffusers with adjustable balance stops shall be supplied with accessible dampers that can be adjusted and fixed in their adjusted positions and that include devices to indicate the positions of the dampers.
(10) Provision shall be made for the free flow of air to all rooms by leaving gaps beneath doors, using louvred doors or installing grilles in doors.