Load & DesignCâu 16 / 110
Air velocity in a duct is calculated by dividing airflow (CFM) by what?
a.The duct length
b.The cross-sectional area of the duct in square feet
c.The static pressure
d.The temperature difference
Giải thích
Velocity in feet per minute equals CFM divided by the duct cross-sectional area in square feet. Excessive velocity causes noise and high friction losses, while too little velocity can reduce throw and mixing. Designers balance velocity against static pressure limits.
Luyện miễn phí toàn bộ 110 câu hỏi — không cần đăng ký.
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