Which of the following humidifiers is classified as passive? ...

[aabwk4]

Which of the following humidifiers is classified as passive?
 
  a. Bubble humidifier c. Passover humidifier
  b. Large-volume nebu-lizer d. Heat and moisture exchanger

Question 2

Which of the following statements about humidifiers is appropriate?
 
  a. The warmer the gas, the less water vapor it can hold.
  b. Evaporation occurs more rapidly with a large water-to-gas surface area.
  c. High peak flows improve the efficacy of a humidifier.
  d. The mass of the water is inversely propor-tional to its capacity to transfer heat.

[peilian]

Answer to Question 1

ANS: D
A heat and moisture exchanger is a passive humidifier. All the others are active humidifiers.

Answer to Question 2

ANS: B
Larger surface areas will increase the amount of evaporation that will occur. The warmer the gas, the more water it can hold. High flows through a humidifier decrease its efficiency, because there is less time for contact between the gas and water. According to the principles of thermodynam-ics, the mass of the water is directly proportional to its capacity to transfer heat. See also Box 6-4.