Flood Restoration Psychrometrics and Humidity Control 3

Question 1

How does increasing indoor temperature during structural drying affect the evaporation rate?

Accepted Answer

It accelerates evaporation by increasing the vapor pressure differential between wet materials and the air

Answer

It slows evaporation by raising the dew point of the space

Answer

It has no measurable effect on evaporation rate

Answer

It reduces evaporation by lowering relative humidity too rapidly

Question 2

'Grain depression' in dehumidifier performance measurement refers to:

Accepted Answer

The difference in grains per pound (GPP) between air entering and air leaving the dehumidifier

Answer

The reduction in total air volume a dehumidifier processes per hour under load

Answer

The decline in structural integrity of materials caused by prolonged moisture exposure

Answer

The drop in air pressure measured across a dehumidifier's filter media

Question 3

Which combination of conditions would MOST impede the drying of a flood-damaged structure?

Accepted Answer

Low temperature and high relative humidity

Answer

High temperature and low relative humidity

Answer

Moderate temperature and moderate relative humidity

Answer

Low temperature and low relative humidity

Question 4

In the IICRC S500 standard, 'Class of Water Damage' classification is determined by:

Accepted Answer

The potential evaporation load — the amount of moisture absorbed into materials that must be removed

Answer

The type and level of contaminants present in the floodwater

Answer

The source and origin point of the water intrusion event

Answer

The estimated dollar value of the structural and contents damage

Question 5

When using psychrometric data to evaluate whether structural drying is progressing, technicians primarily monitor:

Accepted Answer

The reduction in grains per pound (GPP) of moisture in the air

Answer

The rate of temperature increase in the drying space over time

Answer

The increase in structural moisture readings from inspection to inspection

Answer

The total gallons of water extracted from the site by vacuum equipment

Question 6

Secondary wetting or condensation damage during flood restoration most commonly occurs when:

Accepted Answer

Warm, moisture-laden air contacts cool surfaces below the dew point, causing condensation

Answer

Air movers are positioned too close to wet wall cavities

Answer

Dehumidifiers remove moisture too rapidly from porous building materials

Answer

Extraction equipment leaves residual water pooled in subfloor cavities

Question 7

A refrigerant dehumidifier operates at peak efficiency when:

Accepted Answer

Indoor temperatures are between 70–90°F and relative humidity is above 45%

Answer

Indoor temperatures are below 40°F and relative humidity is above 80%

Answer

The space has minimal air circulation to concentrate moisture near the intake

Answer

Operating outdoors to continuously vent extracted moisture to the exterior