IICRC Commercial Drying Specialist (CDS)
| Actual Exam questions with Corrected
Answers
What are some important questions to consider...? - ANSWER Who discovered the water
intrusion and what has been done to stop it? // What type of facility is affected?
// What is the category of the water after it has migrated through the building? //
What pre-existing damage is present or suspected? // Are there critical areas or
equipment that are priority? // What is the category of the water after it has migrated
through the building? // What is the class of saturation and evaporation? // Is the
business insured for Business Interruption (BI)? // Is there an opportunity to help
secure the job by responding quickly to a specific critical area or need? // Are
regulated, hazardous materials or mold present?
Data capture checklists and forms should be... - ANSWER easy to use // comprehensive
to cover many issues // scalable to use on all sizes of facilities
Solid Wood should be within what % of MC of dry standard (with wood calibrated
meter)...? - ANSWER 4%
Non solid wood materials ought to be with what % of the dry standard? - ANSWER 10%
According to the current IICRC S500 Standard, a restorer should establish an initial
dehumidification capacity needed on a project, but should be modified after that
based on... - ANSWER subsequent / following days of psychometric meetings
Some of the other project factors that may need to be considered in adjusting the
dehumidification requirement can be (describe at least three)... - ANSWER An agreed-
upon deadline to complete the job // Power is known to be less than adequate to serve
,the indicated inventory of equipment // The building will be occupied during the drying
process; potentially causing equipment cut-off, frequent opening of doors, higher
moisture load // A schedule imposed by the client (e.g., retail store that wants to
remain open each day) // Required pressure differential to achieve contaminant control
Sizing desiccant dehumidification in larger commercial drying applications
typically begins with determining a target... - ANSWER air changes per hour
TRUE/FALSE - The detailed method of sizing dehumidification is intended for use
by restorers and/or adjusters with any level of experience. - ANSWER FALSE - only
advanced restorers
The build-out density is a factor which considers the ability to_____________ to all
areas of a building as well as the amount of ____________ that needs to be addressed. -
ANSWER The build-out density is a factor which considers the ability to CIRCULATE DRY
AIR to all areas of a building as well as the amount of WALL MATERIALS that needs to
be addressed.
The weather impact factor considers the ______ as well as the ability of the building
envelope to ______. - ANSWER The weather impact factor considers the OUTSIDE
WEATHER as well as the ability of the building envelope to KEEP OUTSIDE AIR
FROM INFILTRATING INSIDE.
Using the "Quick Guidelines for Cooling", how many tons of air conditioning would
you use to condition 75,000 square feet of a grocery store? - ANSWER Go to the quick
guidelines... find the number, and do SQ FT / "factor"... this will get you 215
Direct expansion systems circulate refrigerant through a cold evaporator coil that
cools the air stream that is then... - ANSWER delivered via insulated ducts throughout
the building
,Chiller-water systems circulate conditioned water (chilled or heated) through the
system that is distributed to... - ANSWER ... individual fan/coil units located in
the building
What is ACH? - ANSWER Targeted air change rate per hour
TRUE/FALSE - Critical barriers become effective means of maintaining the drying
environment as well as an engineering control to maintain occupant safety. - ANSWER
TRUE
If outside air ventilation is required, how many CFM per person (occupancy load) can
be used...? - ANSWER 15CFM
Targeted ACH is a function of what...? - ANSWER volume of the space needing to be
dried // the kinds and amounts of building materials that are wet // the degree of
saturation or wetness of the building // the condition of the existing installed HVAC to
help or hinder the process / the prevailing weather conditions outside and how
readily they impact the interior conditions
What are some key points about the sizing rationale...? - ANSWER this is not part of
the standard of care // this is ball part // this is for INITIAL sizing // does not account
for unique job factors // used by competent restorers // calculating initial DH need and
selection of specific equipment // document these
When considering tightness of building... these ought to be considered...? - ANSWER •
Construction components (e.g. doors, windows, vapor retarders, weather-sealing)•
General construction period (e.g. pre-70' looser, post 70's tighter, post-2000 more
moderate)• Number of occupants and trades people on site (e.g., opening doors,
windows, work processes);• Damage to the building envelope (e.g. windows, roof, exterior
walls); • Outdoor wind speed (i.e., higher wind speeds increase filtration rates).
, What is dew point? - ANSWER The temperature at which humidity in air reaches
saturation (100% RH), below which water vapor will condense from that air to
form condensation on surfaces
(Review Page 52, Question 2 of the the manual to practice psychometric readings
and find missing values) - ANSWER (go do it now!)
What are 3 mechanisms of heat transfer? - ANSWER convection, conduction, radiation
What is enthalpy? - ANSWER Enthalpy a measure of the total energy in the air and is
the total of the latent energy and the sensible energy
TRUE/FALSE - Humidity ratio, dewpoint and vapor pressure are all absolute ways
of expressing the moisture content of the air. - ANSWER TRUE
As the temperature of a material is increased, it's internal vapor pressure... - ANSWER
increases
The 2nd law of thermodynamics states... - ANSWER energy flows only from being
concentrated in one place to becoming diffused or dispersed.
What are The two primary mechanisms by which moisture moves through materials? -
ANSWER liquid & vapor
Water activity describes.... - ANSWER the amount of free water available for microbial
growth at the surface
| Actual Exam questions with Corrected
Answers
What are some important questions to consider...? - ANSWER Who discovered the water
intrusion and what has been done to stop it? // What type of facility is affected?
// What is the category of the water after it has migrated through the building? //
What pre-existing damage is present or suspected? // Are there critical areas or
equipment that are priority? // What is the category of the water after it has migrated
through the building? // What is the class of saturation and evaporation? // Is the
business insured for Business Interruption (BI)? // Is there an opportunity to help
secure the job by responding quickly to a specific critical area or need? // Are
regulated, hazardous materials or mold present?
Data capture checklists and forms should be... - ANSWER easy to use // comprehensive
to cover many issues // scalable to use on all sizes of facilities
Solid Wood should be within what % of MC of dry standard (with wood calibrated
meter)...? - ANSWER 4%
Non solid wood materials ought to be with what % of the dry standard? - ANSWER 10%
According to the current IICRC S500 Standard, a restorer should establish an initial
dehumidification capacity needed on a project, but should be modified after that
based on... - ANSWER subsequent / following days of psychometric meetings
Some of the other project factors that may need to be considered in adjusting the
dehumidification requirement can be (describe at least three)... - ANSWER An agreed-
upon deadline to complete the job // Power is known to be less than adequate to serve
,the indicated inventory of equipment // The building will be occupied during the drying
process; potentially causing equipment cut-off, frequent opening of doors, higher
moisture load // A schedule imposed by the client (e.g., retail store that wants to
remain open each day) // Required pressure differential to achieve contaminant control
Sizing desiccant dehumidification in larger commercial drying applications
typically begins with determining a target... - ANSWER air changes per hour
TRUE/FALSE - The detailed method of sizing dehumidification is intended for use
by restorers and/or adjusters with any level of experience. - ANSWER FALSE - only
advanced restorers
The build-out density is a factor which considers the ability to_____________ to all
areas of a building as well as the amount of ____________ that needs to be addressed. -
ANSWER The build-out density is a factor which considers the ability to CIRCULATE DRY
AIR to all areas of a building as well as the amount of WALL MATERIALS that needs to
be addressed.
The weather impact factor considers the ______ as well as the ability of the building
envelope to ______. - ANSWER The weather impact factor considers the OUTSIDE
WEATHER as well as the ability of the building envelope to KEEP OUTSIDE AIR
FROM INFILTRATING INSIDE.
Using the "Quick Guidelines for Cooling", how many tons of air conditioning would
you use to condition 75,000 square feet of a grocery store? - ANSWER Go to the quick
guidelines... find the number, and do SQ FT / "factor"... this will get you 215
Direct expansion systems circulate refrigerant through a cold evaporator coil that
cools the air stream that is then... - ANSWER delivered via insulated ducts throughout
the building
,Chiller-water systems circulate conditioned water (chilled or heated) through the
system that is distributed to... - ANSWER ... individual fan/coil units located in
the building
What is ACH? - ANSWER Targeted air change rate per hour
TRUE/FALSE - Critical barriers become effective means of maintaining the drying
environment as well as an engineering control to maintain occupant safety. - ANSWER
TRUE
If outside air ventilation is required, how many CFM per person (occupancy load) can
be used...? - ANSWER 15CFM
Targeted ACH is a function of what...? - ANSWER volume of the space needing to be
dried // the kinds and amounts of building materials that are wet // the degree of
saturation or wetness of the building // the condition of the existing installed HVAC to
help or hinder the process / the prevailing weather conditions outside and how
readily they impact the interior conditions
What are some key points about the sizing rationale...? - ANSWER this is not part of
the standard of care // this is ball part // this is for INITIAL sizing // does not account
for unique job factors // used by competent restorers // calculating initial DH need and
selection of specific equipment // document these
When considering tightness of building... these ought to be considered...? - ANSWER •
Construction components (e.g. doors, windows, vapor retarders, weather-sealing)•
General construction period (e.g. pre-70' looser, post 70's tighter, post-2000 more
moderate)• Number of occupants and trades people on site (e.g., opening doors,
windows, work processes);• Damage to the building envelope (e.g. windows, roof, exterior
walls); • Outdoor wind speed (i.e., higher wind speeds increase filtration rates).
, What is dew point? - ANSWER The temperature at which humidity in air reaches
saturation (100% RH), below which water vapor will condense from that air to
form condensation on surfaces
(Review Page 52, Question 2 of the the manual to practice psychometric readings
and find missing values) - ANSWER (go do it now!)
What are 3 mechanisms of heat transfer? - ANSWER convection, conduction, radiation
What is enthalpy? - ANSWER Enthalpy a measure of the total energy in the air and is
the total of the latent energy and the sensible energy
TRUE/FALSE - Humidity ratio, dewpoint and vapor pressure are all absolute ways
of expressing the moisture content of the air. - ANSWER TRUE
As the temperature of a material is increased, it's internal vapor pressure... - ANSWER
increases
The 2nd law of thermodynamics states... - ANSWER energy flows only from being
concentrated in one place to becoming diffused or dispersed.
What are The two primary mechanisms by which moisture moves through materials? -
ANSWER liquid & vapor
Water activity describes.... - ANSWER the amount of free water available for microbial
growth at the surface
