1. Atmospheric air at 50°F DB and 70% RH is heated along constant dew point to 90°F DB. The process is called:
(A) Sensible Cooling
(B) Sensible Heating
(C) Humidification
(D) Dehumidification
2. In problem 8.1, the enthalpy of air leaving the heating coil is:
(A) 17.8 Btu/lb
(B) 27.8 Btu/lb
(C) 10 Btu/lb
(D) 62 Btu/lb
3. The enthalpy change (∆h) in problem 8.1 is:
(A) 7.8 Btu/lb
(B) 10 Btu/lb
(C) 18 Btu/lb
(D) 27.8 Btu/lb
4. The relative humidity of air leaving the heating coil in problem 8.1 is:
(A) 18%
(B) 70%
(C) 50%
(D) 23%
5. The specific volume of air leaving the heating coil in problem 8.1 is:
(A) 12.5 ft³/lb
(B) 13.95 ft³/lb
(C) 13.4 ft³/lb
(D) 14.5 ft³/lb
6. The wet bulb temperature of air leaving the heating coil in problem 8.1 is:
(A) 50°F
(B) 62°F
(C) 59°F
(D) 63°F
7. In problem 8.2, air is cooled without condensation from 86°F DB and 37% RH to 80% RH. The process is called:
(A) Sensible Heating
(B) Sensible Cooling
(C) Humidification
(D) Dehumidification
8. The enthalpy change (∆h) in problem 8.2 is:
(A) 6.6 Btu/lb
(B) 32.4 Btu/lb
(C) 25.8 Btu/lb
(D) 10 Btu/lb
9. The dry bulb temperature of air leaving the coil in problem 8.2 is:
(A) 50°F
(B) 59°F
(C) 63°F
(D) 86°F
10. The wet bulb temperature of air leaving the coil in problem 8.2 is:
(A) 59°F
(B) 62°F
(C) 63°F
(D) 50°F
11. In problem 8.3, air enters a heating coil at 50°F DB & 80% RH at 5300 CFM and is heated to 86°F DB without changing moisture content. The relative humidity of air at exit is:
(A) 18%
(B) 23%
(C) 70%
(D) 80%
12. The enthalpy of air leaving the heating coil in problem 8.3 is:
(A) 18.6 Btu/lb
(B) 27.6 Btu/lb
(C) 32.4 Btu/lb
(D) 25.8 Btu/lb
13. The rate of heat transfer for problem 8.3 is:
(A) 214,650 Btu/hr
(B) 200,000 Btu/hr
(C) 150,000 Btu/hr
(D) 5300 Btu/hr
14. In problem 8.4, atmospheric air at 82°F DB & 63°F WB is cooled to 59°F DB without changing moisture content. The final relative humidity is:
(A) 51%
(B) 93%
(C) 80%
(D) 23%
15. The final wet bulb temperature for problem 8.4 is:
(A) 63°F
(B) 59°F
(C) 50°F
(D) 82°F