Chapter 10 Humidification Flashcards
1
Q
1.Calculate the relative humidity of a sample of air that at 21°C (70°F) holds 0.01 kg (0.022 lb) of moisture if the maximum that it can hold at this temperature is 0.015 kg (0.033 lb).
A. 10.70%
B. 25.80%
C. 0.33%
D. 6.70%
E. 93.30%
A
D. 6.70%
2
Q
- Calculate the relative humidity of a sample of air that at 21°C (70°F) holds 0.014 kg (0.031 lb) of moisture if the maximum that it can hold at this temperature is 0.015 kg (0.033 lb).
A. 10.70%
B. 25.80%
C. 0.33%
D. 6.70%
E. 93.30%
A
E. 93.30%
3
Q
3. From a health standpoint, humidity between \_\_\_\_\_ is desirable. A. 15% and 30% B. 25% and 40% C. 35% and 50% D. 45% and 60% E. 55% and 80%
A
C. 35% and 50%
4
Q
4. The steam heated pan humidifier offers high capacity and accurate humidity control if used with a modulating control valve and steam pressure not exceeding: A. 103 kPa (15 psi) B. 10 kPa (1.5 psi) C. 50 kPa (7.3 psi) D. 130 kPa (19 psi) E. 160 kPa (23.2 psi)
A
A. 103 kPa (15 psi)
5
Q
- An air washer is installed on the suction side of the fan so as to:
A. Add latent heat to the air
B. Avoid leakage of water through the joints
C. Add sensible heat to the air
D. Add moisture to the air
E. Avoid leakage of air through the joints
A
B. Avoid leakage of water through the joints
6
Q
6. The steam pressure on a steam grid humidifier should be in the range of: A. 20 kPa to 30 kPa (2.9 to 4.4 psi) B. 25 kPa to 45 kPa (3.6 to 6.5 psi) C. 40 kPa to 55 kPa (5.8 to 8 psi) D. 30 kPa to 60 kPa (4.4 to 8.7 psi) E. 35 kPa to 70 kPa (5.1 to 10.2 psi)
A
E. 35 kPa to 70 kPa (5.1 to 10.2 psi)
7
Q
7. The pan type humidifier has a/an: A. Very High humidification rate B. Very low humidification rate C. Low humidification rate D. High humidification rate E. Moderate humidification rate
A
B. Very low humidification rate
8
Q
8. Calculate the relative humidity of a sample of air that at 21°C (70°F) holds 0.005 kg (0.011 lb) of moisture if the maximum that it can hold at this temperature is 0.015 kg (0.033 lb). A. 10.70% B. 25.80% C. 0.33% D. 6.70% E. 93.30%
A
C. 0.33%
9
Q
9. When the air temperature is lowered without a change in moisture content the relative humidity will: A. Decrease B. Increase C. Not change D. Gain latent heat E. Lose latent heat
A
B. Increase
10
Q
10. When the air temperature is raised without a change in moisture content the relative humidity will: A. Decrease B. Increase C. Not change D. Gain latent heat E. Lose latent heat
A
A. Decrease
11
Q
- Atomizing humidifiers have the disadvantage that:
A. They add moisture to the air
B. They do not require a motor
C. They have no moving parts
D. They have no float valve
E. The water sprayed into the air evaporates leaving the salts that appear as a fine white dust
A
E. The water sprayed into the air evaporates leaving the salts that appear as a fine white dust
12
Q
12. When the air washer is used for dehumidification, the spray water must be \_\_\_\_\_ temperature of the entering air. A. Cooled below the dry bulb B. Heated above the dry bulb C. Heated above the dew point D. Cooled below the dew point E. Cooled below the wet bulb
A
D. Cooled below the dew point
13
Q
13. When the air washer is used for humidification, the spray water must be \_\_\_\_\_ temperature of the entering air. A. Cooled below the dew point B. Heated above the dry bulb C. Heated above the dew point D. Cooled below the dry bulb E. Cooled below the wet bulb
A
C. Heated above the dew point
14
Q
14. One of the wetted element humidifiers group is the \_\_\_\_\_ type. A. Wet B. Spray C. Power D. Steam E. Pan
A
C. Power
15
Q
15. One of the types of humidifiers used for residential purposes is the \_\_\_\_\_ humidifier. A. Dry element B. Pot C. Air washer D. Pan E. Steam
A
D. Pan
