Flood Restoration Psychrometrics and Humidity Control

Question 1

In psychrometrics, which measurement expresses the actual amount of moisture in the air regardless of temperature?

Accepted Answer

Grains per pound (GPP)

Answer

Relative humidity

Answer

Wet bulb temperature

Answer

Dry bulb temperature

Question 2

Relative humidity (RH) is best defined as:

Accepted Answer

The ratio of actual moisture in air to the maximum it can hold at that temperature

Answer

The weight of water vapor per pound of dry air

Answer

The temperature at which air becomes fully saturated

Answer

The rate of evaporation from wet building surfaces

Question 3

As indoor temperature increases during structural drying, what happens to the air's capacity to hold moisture?

Accepted Answer

It increases, allowing more moisture to evaporate from materials

Answer

It decreases, causing condensation on surfaces

Answer

It remains constant regardless of temperature

Answer

It fluctuates in proportion to relative humidity

Question 4

The dew point temperature is defined as:

Accepted Answer

The temperature at which air must be cooled to reach 100% saturation and condensation begins

Answer

The maximum temperature recorded during a drying cycle

Answer

The point at which dehumidifiers stop removing moisture effectively

Answer

The difference between indoor and outdoor ambient temperatures

Question 5

A refrigerant dehumidifier removes moisture from air by:

Accepted Answer

Cooling the air below its dew point to condense moisture onto cold coils, then reheating it

Answer

Heating the air to force moisture to evaporate out

Answer

Filtering moisture particles through HEPA media

Answer

Chemically bonding with water molecules using silica gel

Question 6

According to IICRC S500 guidelines, what relative humidity level should be maintained in the structure to inhibit secondary mold growth during drying?

Accepted Answer

Below 60% RH

Answer

Above 70% RH

Answer

Between 60–70% RH

Answer

Between 40–50% RH

Question 7

Psychrometric charts are primarily used in flood restoration to:

Accepted Answer

Determine the relationship between temperature, relative humidity, dew point, and grains per pound

Answer

Calculate repair costs based on moisture meter readings

Answer

Map the spatial extent of water damage throughout a structure

Answer

Schedule maintenance intervals for drying equipment