Core TradesCâu 99 / 700
CALCULATION: A room measures 20 ft by 15 ft with a 10-ft ceiling. A ventilation system supplies 500 cubic feet per minute (CFM). Approximately how many air changes per hour (ACH) does this provide?
a.5 ACH
b.10 ACH
c.15 ACH
d.20 ACH
Giải thích
Room volume = 20 x 15 x 10 = 3,000 cubic feet. Air per hour = 500 CFM x 60 = 30,000 cubic feet. ACH = 30,000 / 3,000 = 10. Answer 5 forgets the x60 factor properly; 15 and 20 use wrong volume.
Trích dẫn luật: 2025 CA Mechanical CodeLuyện miễn phí toàn bộ 700 câu hỏi — không cần đăng ký.
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