CPR Psychrometric Drying Principles 2

Question 1

On a psychrometric chart, what does the curved line on the far left represent?

Accepted Answer

The saturation curve (100% RH)

Answer

The curved line on the far left of a psychrometric chart is the saturation curve, representing 100% relative humidity where air is fully saturated.

Question 2

A restorer measures dry bulb temperature at 75°F and wet bulb temperature at 62°F. What does the difference between these two readings indicate?

Accepted Answer

The degree of evaporative cooling, reflecting lower relative humidity

Answer

The wet bulb depression (difference between dry and wet bulb temperatures) indicates how much evaporative cooling occurred, which is directly related to the air's relative humidity.

Question 3

During a structural drying job, the dew point inside the structure is 55°F and the surface temperature of an exterior wall is 50°F. What is the likely consequence?

Accepted Answer

Condensation will form on the wall surface

Answer

When a surface temperature falls below the dew point of the surrounding air, moisture condenses on that surface, potentially worsening damage.

Question 4

Which psychrometric property is most directly used to calculate the moisture-removal capacity of a refrigerant dehumidifier?

Accepted Answer

Grain depression (inlet vs. outlet humidity ratio)

Answer

Grain depression — the difference in humidity ratio (grains per pound) between the dehumidifier's inlet and outlet — directly quantifies how much moisture the unit is removing.

Question 5

In psychrometrics, 'enthalpy' refers to:

Accepted Answer

The total heat content (sensible + latent) of moist air

Answer

Enthalpy is the total heat energy in moist air, combining both sensible heat (temperature) and latent heat (moisture content).

(CPR) Certified Professional Restorer Practice Test

(CPR) Certified Professional Restorer Practice Test

CPR Psychrometric Drying Principles 2