Watts Aerco INN 1060N - One Permanent Opening Method

Innovation Water Heaters – Edge [i] Controller
Venting and Combustion Air Design Guide
TAG-0090_A • GF-5056 • 2/20/2020 Technical Support • (800) 526-0288 • Mon-Fri, 8 am - 5 pm EST Page 12 of 39
2. When communicating with the outdoors through horizontal ducts, each opening shall have
a minimum free area of 1 inch
2
per 2,000 BTU/hr. (654 mm
2
/0.59 kW) of total input rating
of all appliances in the space (see Figure 5).
Figure 5: All Combustion Air from Outdoors – Through Horizontal Ducts
1.1.2. ONE PERMANENT OPENING METHOD
One permanent opening shall be provided, commencing within 12 inches (305 mm) of the top of
the enclosure. The opening shall communicate with the outdoors directly or through a vertical or
horizontal duct to the outdoors or spaces that freely communicate with the outdoors (as shown in
Figure 6) and shall have a minimum free area as follows:
• 1 inch
2
per 3,000 BTU/hr (654 mm
2
/0.88 kW) of the total input rating of all appliances
located in the space.