COMBUSTION AIR AND VENTILATION
When determining the installation location for a direct vent water heater, snow accumulation and drifting should be considered in areas where applicable.
VENT TERMINAL CLEARANCES
The vent system must terminate so that proper clearances are maintained as cited in local codes or the current edition of the National Fuel Gas Code ANSI Z223.1/NFPA 54 as follows:
*Minimum 9 in. (23 cm) for appliances with 10,000 btuh (3 Kw) to 50,000 btuh
(15 Kw) inputs and 12 in. (30 cm) for appliances greater than 50,000 btuh (15 Kw) to
a window or door that may be opened
Minimum 18 in. (46 cm) |
| |
| Minimum 3 ft. (91 cm) within a | |
12 in. (30 cm) | height of 15 ft. (4.6 cm) above | |
meter/regulator assembly | ||
above grade or | ||
anticipated snow |
| |
level | Minimum 3 ft. (91 cm) clearance | |
| to service regulator vent outlet |
12 in. (30 cm)
from soffit
Minimum
7 ft. (2.3 m)
above
public sidewalk
or paved driveway
(see footnote 2)
Minimum
12 in. (30 cm)
from sides, above or below a permanently closed window or door
VENT TERMINAL
*
AIR SUPPLY INLET
Minimum |
| Minimum 12 in. (30 cm) |
2 ft. (61 cm) |
| under veranda, porch, |
from outside |
| deck or balcony |
corner |
| (see footnote 1) |
* | * | Minimum |
|
| 3 ft. (91 cm) |
|
| above if within |
|
| 10 ft. (3 m) |
* |
| horizontally to |
| a mechanical air |
supply inlet
* | Minimum 9 in. (23 cm) for appliances with 10,000 btuh (3 Kw) |
| to 50,000 btuh (15 Kw) inputs and 12 in. (30 cm) for appliances greater |
| than 50,000 btuh (15 Kw) to a non mechanical air supply inlet |
| into building or combustion air inlet to another appliance |
AREA WHERE TERMINAL IS NOT PERMITTED | |
1.Permitted only if veranda, porch, deck or balcony is fully opened on a minimum of two sides beneath the floor.
2.A vent shall not terminate above a sidewalk or paved driveway that is located between two single family dwellings and serves both dwellings.
FIGURE 11
15
