A room having dimension 12 m × 10 m × 3.5 m is required to be mechanically ventilated by air-conditioner. The temperature difference between outdoor ambient air and the supply air

Q. A room having dimension 12 m × 10 m × 3.5 m is required to be mechanically ventilated by air-conditioner. The temperature difference between outdoor ambient air and the supply air is 12 °C. Consider three air exchanges per hour. The volumetric specific heat of the air is 1250 J/m³ °C. Assume one ton of refrigeration (TR) is equal to 3.5 kW. The capacity of the air-conditioner for the room in TR will be _____________.

A. 2.5

B. 1.5

C. 0.5

D. 3.5

Ans: 1.5

Solution:

Rate of ventilation = (12 × 10 × 3.5 × 3)/3600=0.35

Cooling load = 1250 × 0.35 × 12 = 5.25 kw = 1.5 TR