HVAC 6011 - Humidification (Chp 10)

Question 1

The residential humidifier is commonly used in the supply plenum of smaller warm air furnaces and consists of a shallow tray partially filled with water is called a:
A) Bypass humidifier
B) Steam grid humidifier
C) Power type humidifier
D) Pan type humidifier
E) Wetted element humidifier

Answer 1

D) Pan type humidifier

Question 2

To prevent condensation on windows when the temperature outside is -29oC the relative humidity should be less than:

A) Greater than 40%
B) 35%
C) 20%
D) 30%
E) 25%

Answer 2

C) 20%

Question 3

Which of the following is not a result of very low humidity?

A) At sufficiently high room temperatures people still feel cool
B) Wood furniture and floor squeaks and cracks
C) Static electricity buildup
D) Throat and nose membranes drying up
E) Evaporation of moisture on the skin decreases

Answer 3

E) Evaporation of moisture on the skin decreases

Question 4

Air washers used in air conditioning systems achieve cooling and dehumidification by:

A) Heating the entering air above its dry bulb temperature
B) Heating the spray water to a temperature above the dry bulb temperature of the entering air
C) Cooling the entering air below its dry bulb temperature
D) Cooling the spray water to a temperature below the dew point temperature of the entering air
E) Heating the spray water to a temperature above the dew point temperature of the entering air

Answer 4

D) ‘‘Cooling the spray water’’ to a temperature below the dew point temperature of the entering air

Question 5

Pan type humidifiers with plates:
A) Are placed in individual rooms to humidify the individual rooms
B) Consist of a shallow pan, partially filled with water in which absorbent plates are placed
C) Can be either a power type or a bypass type
D) Consist of plates in a pan through which water is sprayed by a spinning disc or cone
E) Consist of rotating plates in a pan partially filled with water

Answer 5

B) Consist of a ‘‘shallow pan’’, partially filled with water in which absorbent plates are placed

Question 6

In order to keep humidifiers in top working condition the plates of plate type units should be cleaned by soaking them in a slightly acidic solution and then washing them in soapy water to remove:
A) Corrosion on the plate
B) Grease
C) Soot
D) Mineral salts
E) Dirt

Answer 6

D) Mineral salts

Question 7

When air temperature is raised without the addition of moisture:
A) There is more moisture in the air
B) There is less moisture in the air
C) The air has less capacity to hold moisture
D) The relative humidity rises
E) The relative humidity falls

Answer 7

E) The relative humidity falls

Question 8

From a health standpoint relative humidity should be controlled in the range of:
A) 10 to 35%
B) More than 50%
C) 45 - 70%
D) 35 - 50%
E) Less than 50%

Answer 8

D) 35 - 50%

Question 9

An Air Washer is used to spray water into the air for humidification and can also be used to:

A) Clean the air
B) Dehumidify
C) Heat
D) Cool
E) All answers are correct

Answer 9

E) All answers are correct