IICRC - Applied Structural Drying Verified Questions
And Answers
Air Filtration Device (ADF) Commonly called an air scrubber or negative air machine if airborne
particles need to be reduced, you could use an appropriately installed _______ ________ ________
Air Filtration Device AFD
Assembly Construction Prior to determining the best drying system for affected materials,
restorers should identify and understand the assembly construction (ie wall assembly, floor assembly)
Category 1 water originates from a sanitary source and does not pose substantial risk for dermal,
ingestion, inhalation, or exposure. Uncontaminated and routinely cleaned
Category 2 water contains significant contamination and has the potential to cause discomfort or
sickness if contacted or consumed by humans
Category 3 water is grossly contaminated and can contain pathogenic, toxigenic, or other harmful
agents
Sewage Back Up Category 3
Clean water supply line Category 1
Class 1 Least amount of water absorption and evaporation load - Wet porous materials - water loss
is less then 5% of the area
Class 2 Significant amount of water absorption and evaporation load - water intrusion where wet
represents 5% - 40% of the area.
Class 3 greatest amount of water absorption and evaporation load. Water intrusion where wet
represents over 40% of the area
Class 4 deeply held or bound water. Significant amount of water absorption into low evaporation
materials. Drying may require special drying methods, longer drying time, or substantial water vapor
pressure differentials.
Closed drying system Uses mechanical dehumidification and is not open to outside air. Used if
there are security issues, the outside air is not conductive to drying or when access to outside air is not
possible.
, Conventual refrigerant dehumidifier Removes water vapor from the air by lowering the
temperature of the incoming air to below dew point and causing the water to condense on the coils.
Cold and hot surfaces created with gases inside a closed coil system.
Combination Drying System uses some outdoor air with dehumidifiers to accelerate the drying
process. This can include periodically venting (flushing) the structure, using negative pressure or
using small openings to the outside
Desiccant dehumidifier Removes water vapor from the air through absorption. Usually requires
more amperage as compared to refrigerant dehumidifier. Desiccants create the lowest vapor pressure
which work best on low porosity materials. When a desiccant dehu is drawing outside air and ducting
processed air inside a building it can create positive pressure in the building. To improve desiccant
dehu performance, it may be beneficial to pre-cool the desiccants air intake
Infiltration High humidity outside air could affect the drying climate adversely due to
______________
1. Tightness of the building envelope
2. Prevailing weather
3. HVAC
4. Class of Water
5. Building Construction
5. Build out density Favors that affect the detailed dehumidifier calculation is:
Detailed Dehumidification Calculation See Chart:
Cubic Feet : Divided by 70 = Base Pints per day
Multiply the 5 multipliers together: Build out density x building construction x class of water x HVAC x
Weather Impact = Multiplier
Multiply Base Pints per day x Multiplier = Adjusted Pints Per Day
Dry Standards The unaffected material readings are called ______ ______. You know you can use
this as your drying goal. Your drying goal is this plus 10% of it.
Drying Goal Calculation Dry standard + (Dry standard x 10%) = ____________________
Why does demolition occur 1. Removing Materials to eliminate safety hazards
2. Removing materials that have suffered primary damage and are not restorable
3. Removing porous materials that are holding odor
5. Removing vapor barriers to assist with drying efforts
6. Removing materials to reduce drying time
7. Removing materials to open cavities or areas to provide additional needed services
And Answers
Air Filtration Device (ADF) Commonly called an air scrubber or negative air machine if airborne
particles need to be reduced, you could use an appropriately installed _______ ________ ________
Air Filtration Device AFD
Assembly Construction Prior to determining the best drying system for affected materials,
restorers should identify and understand the assembly construction (ie wall assembly, floor assembly)
Category 1 water originates from a sanitary source and does not pose substantial risk for dermal,
ingestion, inhalation, or exposure. Uncontaminated and routinely cleaned
Category 2 water contains significant contamination and has the potential to cause discomfort or
sickness if contacted or consumed by humans
Category 3 water is grossly contaminated and can contain pathogenic, toxigenic, or other harmful
agents
Sewage Back Up Category 3
Clean water supply line Category 1
Class 1 Least amount of water absorption and evaporation load - Wet porous materials - water loss
is less then 5% of the area
Class 2 Significant amount of water absorption and evaporation load - water intrusion where wet
represents 5% - 40% of the area.
Class 3 greatest amount of water absorption and evaporation load. Water intrusion where wet
represents over 40% of the area
Class 4 deeply held or bound water. Significant amount of water absorption into low evaporation
materials. Drying may require special drying methods, longer drying time, or substantial water vapor
pressure differentials.
Closed drying system Uses mechanical dehumidification and is not open to outside air. Used if
there are security issues, the outside air is not conductive to drying or when access to outside air is not
possible.
, Conventual refrigerant dehumidifier Removes water vapor from the air by lowering the
temperature of the incoming air to below dew point and causing the water to condense on the coils.
Cold and hot surfaces created with gases inside a closed coil system.
Combination Drying System uses some outdoor air with dehumidifiers to accelerate the drying
process. This can include periodically venting (flushing) the structure, using negative pressure or
using small openings to the outside
Desiccant dehumidifier Removes water vapor from the air through absorption. Usually requires
more amperage as compared to refrigerant dehumidifier. Desiccants create the lowest vapor pressure
which work best on low porosity materials. When a desiccant dehu is drawing outside air and ducting
processed air inside a building it can create positive pressure in the building. To improve desiccant
dehu performance, it may be beneficial to pre-cool the desiccants air intake
Infiltration High humidity outside air could affect the drying climate adversely due to
______________
1. Tightness of the building envelope
2. Prevailing weather
3. HVAC
4. Class of Water
5. Building Construction
5. Build out density Favors that affect the detailed dehumidifier calculation is:
Detailed Dehumidification Calculation See Chart:
Cubic Feet : Divided by 70 = Base Pints per day
Multiply the 5 multipliers together: Build out density x building construction x class of water x HVAC x
Weather Impact = Multiplier
Multiply Base Pints per day x Multiplier = Adjusted Pints Per Day
Dry Standards The unaffected material readings are called ______ ______. You know you can use
this as your drying goal. Your drying goal is this plus 10% of it.
Drying Goal Calculation Dry standard + (Dry standard x 10%) = ____________________
Why does demolition occur 1. Removing Materials to eliminate safety hazards
2. Removing materials that have suffered primary damage and are not restorable
3. Removing porous materials that are holding odor
5. Removing vapor barriers to assist with drying efforts
6. Removing materials to reduce drying time
7. Removing materials to open cavities or areas to provide additional needed services
