Question

(a) The developer has proposed to build a teaching room with the dimension of 9.5m(L) x 6m(W) x 3.5m(H) with maximum capacity of 100 people. The teaching room will be used for speech. Determine the amount of absorption required for the optimum reverberation time at unit of m2). (Assuming that the optimum volume per person for teaching room is 2.5m desk, each chair and each person carries the absorption coefficient of 0.8 m2, 0.7 m* and 500Hz (in the 2 and each 0.9m2) (Refer to Figure. Q. 3(a)) (4 marks) 2-6 1-2 08 04 0.2 to 20 30 100 200 300 Volume in 100 Figure. Q. 3(a))

Answer 1

Ans) Volume of room (V) = 9.5 x 6 x 3.50

= 199.5 m³

Capacity of room = 100 people

Average adsorption (A)= (absorption of desk + chair + person) x 100

A = 100( 0.80 + 0.70 + 0.90)

= 240 m²

Reverberation time(t) = 0.162 V / A

t = 0.162 x 199.5 / 240

t = 0.134 s