Definitions Flashcards
(27 cards)
The amount of water vapor in air expressed as a percentage of the air samples total holding capacity
Relative Humidity
A measurement of water vapor weight in a given volume of air. Measured in grains per pound (GPP)
Humidity Ratio
Temperature at which air can hold no more moisture
Dew point
relative humidity at dew point is 100%
Pressure of water vapor on surrounding surfaces and objects, measured in inches of mercury. Directly related to GPP and dew point
Vapor Pressure
Movement of water vapor through a material
Vapor Diffusion
A measure of the ability for vapor to travel through a material
Permeance
Material with a permeance of 1.0 or less
Vapor Barrier
Difference in GPP of the air entering and air leaving a dehumidifier - an indicator of dehumidifier performance
Grain Depression
System of drying where the structure is kept closed to outside air. Used because of security reasons and/or unfavorable outdoor air, or when access to outdoor air is prevented
Closed drying system
System of drying where outdoor air is used. Among other considerations, outdoor air should have a significantly lower GPP than the indoor air
Open drying system
System of drying where some outdoor air is used with dehumidification to accelerate drying. System can include flooding the air, negative pressurization and/or utilizing a small opening to the outside.
Combination drying system
A chemical which reduces the amount of microorganism’s on a surface, but does not eliminate all microbial life
Sanitizer
A chemical which kills all forms of microbial life, but not the microbial spores.
Disinfectant
A chemical which kills all forms of microbial life, including their spores
Sterilizer
Percentage of moisture in wood when compared to an oven-dried sample. Expressed in percentage of the drying weight.
Moisture content
Materials that readily absorb or release moisture based on the surrounding humidity
Hygroscopic
Association of home appliance manufacturers. Publishes test results for water removal of dehumidifiers at conditions of 80 degrees/60%RH over 24 hours
AHAM
A guide word in an IICRC standard that means that the practice of procedure is mandatory due to natural law or legal requirements.
Shall
A guide word in an IICRC standard that means that the practice is a critical procedure to be followed, but not required by law or legal requirements
Should
A guide word in an IICRC standard that means that the practice is advised or suggested, while not a part of the standard of care
Recommended
The amount of moisture in a material compared to the materials oven dried weight with
Moisture content
Differences in moisture in different areas of a material
Moisture content gradient
Liquid changing to a vapor
Evaporation
Vapor changing to a liquid
Condensation
