Gas & FuelCâu 61 / 110
Combustion air is taken from outdoors using two openings, one high and one low. The rule is 1 square inch of free area per 4,000 BTU/hr for each opening when using direct outdoor openings. For a 200,000 BTU/hr appliance load, what is the minimum free area of each opening?
a.50 in^2
b.25 in^2
c.40 in^2
d.100 in^2
Giải thích
Each opening = load / 4,000 = 200,000 / 4,000 = 50 in^2 of free area. When two vertical (direct outdoor) openings are used, each is sized at 1 square inch per 4,000 BTU/hr, one within 12 in of the top and one within 12 in of the bottom. Louvers reduce free area, so gross opening size must be increased to compensate.
Trích dẫn luật: IFGC §304.6Luyện miễn phí toàn bộ 110 câu hỏi — không cần đăng ký.
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