Please answer following questions:-

8.Cooling system load is 48,000 Btu/hr. sensible. How much chilled air is required to satisfy the load if the system is designed for a 20A????1F temperature rise?
4,180.
3,180 CFM.
4,800 CFM.
2,180 CFM.

9.Briefly describe the difference between sensible and latent heat.

Latent heat produces no temperature change. Sensible heat affects the amount of water vapor in the air.
Latent heat produces temperature change. Sensible heat affects the amount of water vapor in the air.
Sensible heat produces no temperature change. Latent heat affects the amount of water vapor in the air.
Sensible heat produces temperature change. Latent heat affects the amount of water vapor in the air.

10.What is the wet-bulb temperature of air at 75A????1F, and 60% relative humidity? (You need a psychrometric chart to answer this question)
35.2A????1F.
45.2A????1F.
55.2A????1F.
65.2A????1F.

11.What is the humidity ratio of air at 75A????1F, and 60% relative humidity? (You need a psychrometric chart to answer this question)
78 grains of moisture per lb. of dry air.
68 grains of moisture per lb. of dry air.
88 grains of moisture per lb. of dry air.
58 grains of moisture per lb. of dry air.

12.What is the rate at which heat is liberated for a 1,000-gpm (gallons per minute) water flow cooling from 150A????1F to 110A????1F?
20 MMBTU/hr.
25 MMBTU/hr.
30 MMBTU/hr.
35 MMBTU/hr.

13.What is the enthalpy (heat) of air at 75A????1F, and 60% relative humidity? (You need a psychrometric chart to answer this question)
25 BTU per lb of dry air
30 BTU per lb of dry air.
35 BTU per lb of dry air.
40 BTU per lb of dry air.

14. What is the density of air at 75A????1F, and 60% relative humidity? (You need a psychrometric chart to answer this question)
0.071 lb/ft3.
0.073 lb/ft3.
0.077 lb/ft3.
0.079 lb/ft3.

15.What will be the cooling load for a wall 8 ft high by 600 ft long facing South with a Total Equivalent Temperature Differential (TETD = 16A????1F). (Note: The TETD value corresponds to a wall assembly of U-value of 0.27 BTU/(hr.ft2.A????1F) or a wall assembly group L, as given in Table 2.13 on pg.41. Assuming light colored wall, and selecting the max. TETD value for the particular orientation i.e. North, South, etc.)
326,400 BTU/hr.
345,540 BTU/hr.
76,800 BTU/hr.
20,736 BTU/hr.

16.What will be the heating load for a 6' x 6' window constructed of single-pane clear glass, if the difference between the indoor and outdoor temperature is 68A????1F? (Assume U = 1.05 BTU/(hr.ft2.A????1F) for a single pane window)
3,264.4 BTU/hr.
5,540.4 BTU/hr.
2,570.4 BTU/hr.
1,346.4 BTU/hr.

17.Which of the following statements are correct?
i. Heating and cooling processes represent a change in sensible heat.
ii. Humidification and dehumidification processes represent a change in latent heat.
iii. Sensible heat + Latent heat = Total heat
Only i & iii.
i, ii & iii.
Only ii & iii.
Only i & ii.

18.State the factors that affect environmental comfort and their general ranges of values, where applicable?

Temperature and humidity - low limit values for comfort are 68A????1F, 30% RH; high limit values for comfort are 79A????1F, 55% RH
Heat-rate and humidity - low limit values for comfort are 68 BTU/hr.,
30% RH; high limit values for comfort are 79 BTU/hr., 55% RH
Temperature and humidity - low limit values for comfort are 75A????1F, 60% RH; high limit values for comfort are 85A????1F, 90% RH
Temperature and humidity - low limit values for comfort are 68A????1F, 80% RH; high limit values for comfort are 79A????1F, 100% RH

19.What heating load would result from the minimum outside air for a classroom with ventilation requirement of 650 CFM, if the design temperature difference is 68A????1F?
33,750 BTU/hr.
16,750 BTU/hr.
48,620 BTU/hr.
52,560 BTU/hr.

20.The cooling load inside an office complex 240,000 BTU/hr. What cooling equipment would be needed to maintain comfort inside the office complex? (Note: 1 ton = 12,000 BTU/hr.)
12-ton chiller
15-ton chiller.
18-ton chiller.
20-ton chiller.