FIGURE 3A
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.
VENTING CLEARANCES
•18” minimum in all directions from any obstruction that may interfere.
•18” minimum from the ground and 12” from ceiling overhangs, see Figure 4.
•The direct vent terminal shall terminate at least 3 feet above any forced air inlet located within 10 feet, see Figure 5.
•9” minimum horizontally from or above any door, window or gravity air inlet into the building (50,000 BtuH input or less.)
•12” minimum horizontally from or above any door, window or gravity air inlet into the building (over 50,000 BtuH input).
•12” minimum below any door, window or gravity air inlet into the building (50,000 BtuH input or less).
•18” minimum below any door, window or gravity air inlet into the building (over 50,000 BtuH input).
•18” minimum from other gravity or natural appliance outlet vents when directly above or 135° to either side of center line, see Figure 6.
•36” minimum from any outlet vents when directly below or 45° to either side of center line, see Figure 7.
•36” minimum in all directions from any other forced air appliance outlet vent, see Figure 7.
•The location selection must provide clearances for servicing and proper operation of the water heater, see Figure 8.
•Vent termination must not be within 4 feet of any items such as gas meters, gas valves or other gas regulating equipment.
6
FIGURE 4
WARNING
Vent termination must not be within 4 feet of any items such as gas meters, gas valves or other gas regulating equipment.
OPTIONAL WIRE GRILL
When the water heater vent cap is low enough to be touched accidentally, or is accessible to small children, installation of a protective vent cover is recommended. Some local codes may require a vent cap cover. Figure 9 shows the optional wire vent cap protector available from the water heater manufacturer.
A wire mesh chain link fence (as shown in Figure 9) may be used instead of the factory cover. Care should be taken to maintain adequate ventilation around the vent cap. If a chain link fence is installed, it must not be used as a storage area for items that may block proper ventilation.
FIGURE 5
