Crown Aruba 5 Installation Manual
9
Using the Outdoor Combustion Air Method
1) Openings must be installed between the boiler room and the outdoors or a ventilated space, such as an attic or crawl
space, which communicates directly with the outdoors.
2) Two openings are required. The top edge of the upper opening must be within 6 inches of the ceiling. The bottom edge
of the lower opening must be within 6 inches of the oor.
3) Size openings and ducts as follows:
• Vertical ducts or openings directly outdoors (Figure 5.2, Figure 5.3, and Figure 5.4) - Each opening must have a free
cross sectional area of 1 square inch per 4000 BTU/hr of the total input of all gas-red appliances in the boiler room.
Minimum opening size is 3 inches.
• Openings to outdoors via horizontal ducts (Figure 5.5) - Each opening must have a free cross sectional area of 1
square inch per 2000 BTU/hr of the total input of all gas red appliances in the boiler room. Minimum opening size
is 3 inches.
• The “free area” of an opening takes into account the blocking eect of mesh, grills, and louvers. Where screens are
used, they must be no ner than ¼” (4 x 4) mesh.
6” M A X
6” M A X
FIGURE 5.4: OUTDOOR COMBUSTION AIR METHOD: USING OPENINGS INTO BOILER ROOM
6” MAX
6” MAX
FIGURE 5.5: OUTDOOR COMBUSTION AIR METHOD: USING HORIZONTAL DUCTS INTO BOILER ROOM