Confined Space Installation | a. One opening MUST commence within 12″ (304.8mm) | |||||||||||||||||
NOTE: A confined space is defined as an area with less than 50 | of the floor and the second opening MUST commence | |||||||||||||||||
within 12″ (304.8mm) of the ceiling. | ||||||||||||||||||
cubic feet (1.43M)per 1,000 BTUH (2.33 cm2/kW) input rating for | b. Size openings and ducts per Table 1. | |||||||||||||||||
all gas appliances installed in the area. | ||||||||||||||||||
c. Horizontal duct openings require 1 square inch of free | ||||||||||||||||||
Requirements | ||||||||||||||||||
area per 2,000 BTUH (11 cm2/kW) of combined input | ||||||||||||||||||
1. Provide the space with sufficient air for proper combustion | for all gas appliances in the space (see Table 1). | |||||||||||||||||
d. Vertical duct openings or openings directly | ||||||||||||||||||
and ventilation of flue gases using horizontal or vertical | ||||||||||||||||||
communicating with the outdoors require 1 square inch | ||||||||||||||||||
ducts or openings. | ||||||||||||||||||
of free area per 4,000 BTUH (5.5 cm2/kW) for | ||||||||||||||||||
2. Fig. 6 illustrates how to provide combustion and ventilation | ||||||||||||||||||
combined input of all gas appliances in the space (see | ||||||||||||||||||
air. A minimum of two permanent openings, one inlet and | ||||||||||||||||||
Table 1). | ||||||||||||||||||
one outlet, are required. | ||||||||||||||||||
|
|
|
|
|
|
|
|
|
|
|
|
| ||||||
|
|
|
| This installation NOT approved in Canada | Gas Vent |
|
|
|
| |||||||||
|
|
|
|
|
|
|
| |||||||||||
|
|
|
|
|
|
| ||||||||||||
|
|
|
| Gable Vent |
|
|
|
|
|
|
|
|
|
|
|
|
| |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| ||
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| ||
Gas Vent
Ventilated Attic |
|
|
|
|
|
|
Top Above Insulation |
| Gable Vent |
|
|
|
|
Alternate Inlet Air (1) |
|
|
|
| ||
|
| Gas Vent |
| Outlet | Outlet | |
|
| Ventilated Attic |
| Air (1) | ||
Outlet Air (1) | Soffit Vent |
| Air (2) | |||
Top Above Insulation |
|
|
|
| ||
|
|
|
|
|
| |
|
| OutletAir (1) | Soffit Vent | Inlet | Inlet | |
|
| Air (1) | ||||
|
|
|
|
| Air (2) | |
|
|
|
|
|
| |
|
|
| Inlet |
| Minimum One Inlet and One Outlet Air Supply is Required | |
|
|
|
| May be in any Combination Shown |
| |
| Inlet |
| Air (2) |
| Inlet Air Opening Must be Within12″ of floor |
|
Ventilated Crawl Space |
|
|
|
| ||
|
|
| Outlet Air Opening Must be Within12″ of ceiling |
| ||
alternate Inlet Air (1) | Air (1) |
|
|
|
| |
|
|
|
| (1) 1 Square Inch per 4000 BTUH |
| |
|
|
|
|
|
| |
|
|
|
|
| (2) 1 Square Inch per 2000 BTUH |
|
|
|
|
|
|
| A07704 |
Fig. 6 - Outside Air
(This is ONLY a guide. Subject to codes of country having jurisdiction).
58HDV
3.One opening MUST be within 12″ (304.8mm) of the floor and the second opening within 12″ (304.8mm) of the ceiling.
a.1 sq. in of free area per 3,000 BTUH (7 cm2/kW) for combined input of all gas appliances in the space (see Table 1) and
b.not less than the sum of the areas of all vent connectors in the space.
The opening shall commence within 12″ (304.8mm) of the top of the enclosure. Appliances shall have clearances of at least 1″ (25.4mm) from the sides and back and 6″ (152.4mm) from the front. The opening shall directly communicate with the outdoors or shall communicate through a vertical or horizontal duct to the outdoors or spaces (crawl or attic) that freely communicate with the outdoors.
4.Size openings and ducts per Table 1.
a.Indoor openings that comply with the Indoor Combustion Air Method below and
b.Outdoor openings located as required in the Outdoor Combustion Air Method above and
c.Outdoor openings sized as follows.
(1.) Calculate the Ratio of all Indoor Space volume divided by required volume for Indoor Combustion Air Method.
(2.) Outdoor opening size reduction Factor is 1 minus the Ratio in 1) above.
(3.) Minimum size of Outdoor openings shall be the size required in Outdoor Combustion Air Method above multiplied by reduction Factor.
5.Horizontal duct openings require 1 square inch of free area per 2,000 BTUH of combined input for all gas appliances in area (see Table 1).
6.Vertical duct openings or openings directly to outside require 1 square inch of free area per 4,000 BTUH (5.5 cm2/kW) for combined input of all gas appliances in area (see Table 1).
9
