Wrt 2025
Category 1 - answer1 (previously known as "clean") - originates from a sanitary water
source
Category 2 - answer(previously known as "gray") - contaminated; potentially causes
discomfort or sickness
Category 3 - answer(previously known as "black") - grossly contaminated; includes
toxins, pathogens
• Regulated or hazardous materials and mold - answer(creating special situations) - IEP
recommended
Class of Water - answer(quantity; anticipated evaporation rate; initial dehumidifier
calculations)
Class 1 - answer- (least amount of water, absorption and evaporation) wet less than
~5% of combined floor, wall, and ceiling surface area - minimal moisture absorption into
the materials
Class 2 - answer(large amount of water, absorption and evaporation) wet between ~5 -
~40% of combined floor, wall, and ceiling surface area - minimal moisture absorption
into the materials
Class 3 - answer- (greatest amount of water, absorption and evaporation) wet more
than ~40% of combined floor, wall, and ceiling surface area - minimal absorption into
the materials
Class 4 - answer- (deeply held or bound water) - (e.g., hardwood; lath and plaster;
concrete) - water hidden, trapped, or bound in low evaporation assemblies; requires
controlled drying techniques, low vapor pressure, specialty equipment probable
Principles of Drying - answerRemove excess / Evaporation / Dehumidification
(ventilation) / Temperature control
Extraction tools: - answerLight wand - perimeter of water loss; extract glue-down
carpets; follow-up extraction-stationary tool • Stationary tool (e.g., Water claw; Flash
Xtractor) - subsurface tool; extract carpet/cushion together • Self-propelled tools (e.g.,
Rover; Xtreme Xtractor) -self-propelled riding tool; multi-speed; extract carpet and
cushion • Vacuum squeegee - concrete; hardwood; vinyl; laminate • Submersion pumps
- Formula - (ft2 x inches deep) ÷ 12" = ft3 water x 7.48 = water volume
, Evaporation tools - answerAirmovers - centrifugal (laminar); axial (high-amperage; low-
amperage; focus ability) o placement -5-45 degree focus; almost touching wall; always
round up to next number § Initially one airmover each affected room
• Airmovers - answercentrifugal (laminar); axial (high-amperage; low-amperage; focus
ability) o placement -5-45 degree focus; almost touching wall; always round up to next
number § Initially one airmover each affected room § Additionally, add one: • Every 50-
70 sq. ft. wet floor and walls up to 24 inches high • Every 100-150 sq. ft. of affected wet
ceiling and walls over 24 inches high • Each wall offset greater than 18 inches o One
per 14 LF of all only (if only lower wall and limited flooring) o One per small areas under
25 sq. ft. if upper walls and ceilings not affected o safety screens - intake and output
areas; clean with compressed air; do not block intake o electrical safety - lightweight
extension cords; three-prong plugs; electrical cord safety
Structural Cavity Drying Systems (SCDS) - answerVented-ducted (e.g., Turbovents 18"-
48" widths; Octi-dry; Air Wolf) o injected (e.g., Injectidry; Dri-Force; Omni-dry; Direct-it
In)
Floor Drying Systems - answervented (e.g., Air Wolf) o injected - negative air
mats/panels (e.g., Dri-Force; Injectidry) o air-blanket style
Air Filtration Devices - answerAFDs (negative air machines - NAM; air scrubbers; HEPA
filters)
Dehumidifier Ranges - answerUnderstanding where temperature, RH, and GPP ratings
are out of working ranges
AHAM rating: - answerpints removed at 80º F / 60% RH in 24 hours
Refrigerants - answerMost efficient operating conditions 70º - 90º F. (most energy
efficient is an LGR)
Desiccants - answermost efficient with incoming air from coolest/driest air possible;
capable of creating greatest pressure differentials (air and vapor pressures); produces
low humidity ratio (gpp) important to dry Class 4 materials, dense materials, and
complex systems.
Uses - answerclosed-drying environments; multiple layers of materials; security
limitations; high outside (and inside) humidity conditions; no ventilation ports; basement
areas
Initial dehumidification recommendations - answer(psychrometric readings dictate
requirements after first day)
Inspection equipment: - answerMoisture sensor
Thermo-hygrometer
Category 1 - answer1 (previously known as "clean") - originates from a sanitary water
source
Category 2 - answer(previously known as "gray") - contaminated; potentially causes
discomfort or sickness
Category 3 - answer(previously known as "black") - grossly contaminated; includes
toxins, pathogens
• Regulated or hazardous materials and mold - answer(creating special situations) - IEP
recommended
Class of Water - answer(quantity; anticipated evaporation rate; initial dehumidifier
calculations)
Class 1 - answer- (least amount of water, absorption and evaporation) wet less than
~5% of combined floor, wall, and ceiling surface area - minimal moisture absorption into
the materials
Class 2 - answer(large amount of water, absorption and evaporation) wet between ~5 -
~40% of combined floor, wall, and ceiling surface area - minimal moisture absorption
into the materials
Class 3 - answer- (greatest amount of water, absorption and evaporation) wet more
than ~40% of combined floor, wall, and ceiling surface area - minimal absorption into
the materials
Class 4 - answer- (deeply held or bound water) - (e.g., hardwood; lath and plaster;
concrete) - water hidden, trapped, or bound in low evaporation assemblies; requires
controlled drying techniques, low vapor pressure, specialty equipment probable
Principles of Drying - answerRemove excess / Evaporation / Dehumidification
(ventilation) / Temperature control
Extraction tools: - answerLight wand - perimeter of water loss; extract glue-down
carpets; follow-up extraction-stationary tool • Stationary tool (e.g., Water claw; Flash
Xtractor) - subsurface tool; extract carpet/cushion together • Self-propelled tools (e.g.,
Rover; Xtreme Xtractor) -self-propelled riding tool; multi-speed; extract carpet and
cushion • Vacuum squeegee - concrete; hardwood; vinyl; laminate • Submersion pumps
- Formula - (ft2 x inches deep) ÷ 12" = ft3 water x 7.48 = water volume
, Evaporation tools - answerAirmovers - centrifugal (laminar); axial (high-amperage; low-
amperage; focus ability) o placement -5-45 degree focus; almost touching wall; always
round up to next number § Initially one airmover each affected room
• Airmovers - answercentrifugal (laminar); axial (high-amperage; low-amperage; focus
ability) o placement -5-45 degree focus; almost touching wall; always round up to next
number § Initially one airmover each affected room § Additionally, add one: • Every 50-
70 sq. ft. wet floor and walls up to 24 inches high • Every 100-150 sq. ft. of affected wet
ceiling and walls over 24 inches high • Each wall offset greater than 18 inches o One
per 14 LF of all only (if only lower wall and limited flooring) o One per small areas under
25 sq. ft. if upper walls and ceilings not affected o safety screens - intake and output
areas; clean with compressed air; do not block intake o electrical safety - lightweight
extension cords; three-prong plugs; electrical cord safety
Structural Cavity Drying Systems (SCDS) - answerVented-ducted (e.g., Turbovents 18"-
48" widths; Octi-dry; Air Wolf) o injected (e.g., Injectidry; Dri-Force; Omni-dry; Direct-it
In)
Floor Drying Systems - answervented (e.g., Air Wolf) o injected - negative air
mats/panels (e.g., Dri-Force; Injectidry) o air-blanket style
Air Filtration Devices - answerAFDs (negative air machines - NAM; air scrubbers; HEPA
filters)
Dehumidifier Ranges - answerUnderstanding where temperature, RH, and GPP ratings
are out of working ranges
AHAM rating: - answerpints removed at 80º F / 60% RH in 24 hours
Refrigerants - answerMost efficient operating conditions 70º - 90º F. (most energy
efficient is an LGR)
Desiccants - answermost efficient with incoming air from coolest/driest air possible;
capable of creating greatest pressure differentials (air and vapor pressures); produces
low humidity ratio (gpp) important to dry Class 4 materials, dense materials, and
complex systems.
Uses - answerclosed-drying environments; multiple layers of materials; security
limitations; high outside (and inside) humidity conditions; no ventilation ports; basement
areas
Initial dehumidification recommendations - answer(psychrometric readings dictate
requirements after first day)
Inspection equipment: - answerMoisture sensor
Thermo-hygrometer
