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IICRC - APPLIED STRUCTURAL
DRYING
If airborne particles need to be reduced, you could use an appropriately installed
- ANSWERS-Air Filtration Devise If asbestos is found or suspected in building materials, removal shall be removed by a
- ANSWERS-Licensed Asbestos Abatement Contractor Licensed Asbestos Abatement Contractor - ANSWERS-LAAC Is water is suspected to contain a hazardous material the termination shall be made by a - ANSWERS-qualified specialized expert Surface temperatures of the materials you are drying - ANSWERS-Maintain Cannot hold water condensation. - ANSWERS-Cooler Air This is industry standards best practice. - ANSWERS-Should
Indoor Environmental Professional - ANSWERS-IEP The IICRC (2003) states that "The role of an IEP is to perform an assessment of the fungal ecology of property, systems and contents at the job site, create a sampling strategy, sample the indoor environment, interpret laboratory data and determine Condition 1, 2 and 3 status for the purpose of establishing a scope of work (pre- remediation assessment) and/or when necessary to verify the return to normal fungal ecology. - ANSWERS-Indoor Environmental Professional personal protective equipment - ANSWERS-PPE Water is trapped underneath and caused the flooring to do this - ANSWERS-Cupping The water is on the top of the flooring causing the flooring planks to do this - ANSWERS-Crowning British thermal unit. The quantity of heat required to raise the temperature of one pound of water one degree Fahrenheit. - ANSWERS-BTU CFM of Dehu x Grain Depression / 71 = PPD - ANSWERS- Converting Grain Depression to PPD
Environmental Protection Agency An independent federal agency established to coordinate programs aimed at reducing pollution and protecting the environment - ANSWERS-EPA study of the relationship between air, humidity and temperature and their effect on various materials and comfort levels - ANSWERS- Psychrometric chart consisting of lines and curves that shows the relationship between air volume, temperature and relative humidity, and from which a variety of other information (humidity ratio-gpp, dew point, vapor pressure, etc.) relating to drying may be determined - ANSWERS-Psychrometric chart ideal drying situation in which the rate of evaporation is equal to or slightly less than the rate of dehumidification or ventilation. - ANSWERS-Balanced drying migration of air into and area from outside area due to high VP differential - ANSWERS-Infiltration a measure of water flow through material(s) of specific thickness. - ANSWERS-Permeance work together and when managed, enable achieving target time for drying influences movement toward equilibrium - wet seeks dry; hot
seeks cold; high vapor pressure seeks low vapor pressure - ANSWERS-Humidity, airflow and temperature (HAT) % rotting fungi growth IN wood % - non-rotting fungi growth ON wood - ANSWERS-20% 16% Gallons per cubic foot of water depth - ANSWERS-7. % - available power to use per NEC per amperage in circuit - ANSWERS-80% Residential v. commercial - generally, residential amp / commercial amp (consider never using over 80% of available amperage) - ANSWERS- 15 20 Senses moisture in materials over 17% MC; helps determine perimeter of water damage; unable to determine which layer is wet or when dry - ANSWERS-Moisture Sensor determines temperature / RH in all required atmospheric areas of inspection; helps determine open or closed drying system; further determines dehumidifier recommendations after initial placement - ANSWERS-Thermo-hygrometer
Ideal temperature for a Refrigerant of LGR dehumidifier - ANSWERS-70°F - 90°F higher gpp inside compared to lower gpp outside - ANSWERS-Open drying system most effective and expedient drying time - ANSWERS-Effective Extraction Sill plates or other "hidden" areas usually are the areas to dry
- ANSWERS-Last Areas to Dry When using extension cords or equipment, you should ensure they contain a ground conductor. Equipment should be UL certified. - ANSWERS-Electrical Safety The movement of water vapor and or air from the insure of a structure to the outside of a structure - ANSWERS-Exfiltration Difference in GPP of the air entering and air leaving a dehumidifier - an indicator of dehumidifier performance. - ANSWERS-Grain Depression Using a negatively pressurized mat system is an effective way to speed the drying o f hardwood floor assemblies with air between finished floor and subfloor - ANSWERS-Hardwood Floor Drying
the movement of energy from a warmer object to a cooler object - ANSWERS-Heat Transfer Low grain refrigerant dehu - uses the same technology as a conventual refrigerant, but the air is pre-cooled before the cold coils are pre warmed before the heat exchanger, heat pipe or heat siphon, resulting in better efficiency as compared to a conventional refrigerant dehu. LGR dehu continue to remove a significant amount of water vapor below 40 GPP - ANSWERS-LGR Easily absorb and desorb (release) moisture. Usually, the first materials to become damaged by abnormal water. Can be easily damaged from high humidity (secondary damage) - ANSWERS- Hygroscopic Materials Commonly called an air scrubber or negative air machine if airborne particles need to be reduced, you could use an appropriately installed
- ANSWERS-Air Filtration Device (ADF) AFD - ANSWERS-Air Filtration Device Prior to determining the best drying system for affected materials, restorers should identify and understand the assembly construction (ie wall assembly, floor assembly) - ANSWERS-Assembly Construction
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. - ANSWERS-Class 4 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. - ANSWERS-Closed drying system 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. - ANSWERS-Conventual refrigerant dehumidifier 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 - ANSWERS-Combination Drying System 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 - ANSWERS- Desiccant dehumidifier
High humidity outside air could affect the drying climate adversely due to - ANSWERS-Infiltration Favors that affect the detailed dehumidifier calculation is: - ANSWERS-1. Tightness of the building envelope
- Prevailing weather
- HVAC
- Class of Water
- Building Construction
- Build out density 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 - ANSWERS-Detailed Dehumidification Calculation 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. - ANSWERS-Dry Standards Dry standard + (Dry standard x 10%) = - ANSWERS-Drying Goal Calculation
- Removing Materials to eliminate safety hazards
Total PPD (pints per day) removal recommendation / dehumidifier AHAM rating = of Calculation - ANSWERS-Number of Dehu Calculation Cubic Footage x Chart Factor (ACH) / 60 minutes = Total calculation - ANSWERS-Cubic Feet Per Minute Calculation Total CFM / Desiccant CFM Rating = Total of Calculation - ANSWERS-Total Number of Desiccant Dehumidifier Calculation Return structure, systems or contents to an acceptable condition and inhibit microbial growth. Along with the above considerations where applicable, it is recommended the drying goal be within 10% of the dry standards. - ANSWERS-Drying goals may be at or above the dry standard should be documented as they relate to specific materials. The restorer should establish drying goals that would be expected to normally starts by measuring similar materials in an unaffected area of the building. These unaffected material readings are called a dry standard. - ANSWERS-Establishing Drying Goals If drying a crawlspace and the surface temperature of the wood framing is 80°F what is the dew point temperature of the crawlspace air that would provide the greatest potential for evaporations
A. 45°F
B. 65°F
C. 85°F
D. 105°F - ANSWERS-A. 45°F - best answer is always the lowest option A method to determine the effectiveness of the drying conditions is to measure the difference between the surface temperature of the materials and the of the air - ANSWERS-Dew Point To decrease drying time of wet materials, restorers can increase the of moisture in the materials. This accelerates the water molecules to make them move to the air. - ANSWERS-Temperature The day with the greatest vapor pressure differential between air and material was Monday - Surface Vapor Pressure: .90 Air Vapor Pressure: .73 = Monday Vapor Pressure Differential:. Tuesday- Surface Vapor Pressure: 1.51 Air Vapor Pressure: .55 = Tuesday Vapor Pressure Differential:. Wednesday- Surface Vapor Pressure: 1.04 Air Vapor Pressure: .31 = Wednesday Vapor Pressure Differential: .73 - ANSWERS-Tuesday In the driest environments, we'll find? - ANSWERS-Coldest Dew Point
3 - ANSWERS-Convection Conduction Radiation Heat flows from areas of warm temperatures to areas of cool temperature in the absence of other factors. The greater the temperature difference between warmer and cooler areas (this is called ) the faster the heat flows. - ANSWERS-Temperature Gradient When a surface's temperature is warmer than the dew point of the air space occurs, removing moisture from the surface. - ANSWERS-Evaporation is the actual amount of moisture in the air. This amount is expressed in weight as the number of grains of moisture per point of dry air (gpp). The more moisture present in the air, the heavier the moisture will weight. - ANSWERS- Humidity Ratio Humidity Ratio is the actual amount of moisture in the air. This amount is expressed in weight as the number of grains of moisture per point of dry air (this is the ). The more moisture present in the air, the heavier the moisture will weight. - ANSWERS-GPP is the pressure that all substances in a gaseous state exert on surrounding surfaces. the
amount of pressure is determined by the concentration of gases, such as water vapor, in proportioned to the area in which it is contained - ANSWERS-Vapor Pressue from areas of high water vapor pressure to areas of low water vapor pressure seeking equilibrium - ANSWERS-Moisture moves Moisture moves from areas of high water vapor pressure to areas of low water vapor pressure seeking equilibrium - ANSWERS- Equilibrium Increasing the material temperature and the water temperature within the material will increase the energy within the water molecule, and this will increase the of - ANSWERS-rate of evaporation Drying efforts need to reverse the mechanism by which the moisture entered. Free water is drawn out through capillary action, followed by excess bound water via diffusion. - ANSWERS-Moisture Movement in Materials is the movement of a liquid through the pores of a material. - ANSWERS-capillary action is the movement of water vapor molecules through the material. Driven by moisture gradients as well as vapor pressure differential from inside the material to one or both outer surfaces of the material. - ANSWERS-moisture diffusion
HEPA Filters are rated to remove % of particles down to micron - ANSWERS-99.97%
99.97% of particles down to 0.3 micron - ANSWERS-HEPA Filters are rated to remove Identifying suspected hazards is a critical step in the inspection process. It is also required by safety and health - ANSWERS-Regulations When using extension cords, you should ensure they contain a
- ANSWERS-Ground Conductor A measure of the amount of moisture present in the structure of a material. - ANSWERS-Moisture Content The measurement of the amount of moisture contained in a material on the relative scale. - ANSWERS-Moisture Level The primary mechanisms through which moisture moves through hygroscopic materials are capillary action and diffusion - ANSWERS- Moisture Movement
If presumed asbestos containing materials or lead in materials are discovered, you should stop activities that can potentially disturb the hazardous materials. If asbestos is found or suspected, removal shall be performed by a Licensed Asbestos abatement contractor - ANSWERS-Regulated Materials the amount of water vapor present in air expressed as a percentage of the amount needed for saturation at the same temperature. - ANSWERS-Relative Humidity (RH) the science of how energy changes. Examples : Wet goes to dry, hot goes to cold, high pressure goes to low pressure - ANSWERS-Thermodynamics You are working on a class 2 water loss that has two affected areas. Area 1 is 3750CF and Area 2 is 2700CF You plan to dry both areas together using an LGR Dehu rated at 80 ppd at AHAM. How many of these dehus do you need to install on this project. - ANSWERS-2 LGR dehumidifiers When you are calculating equipment do you A. Use the exact number B. Always Round down C. Always round up - doesn't matter the decimal amount - ANSWERS-C. Always round up - doesn't matter the decimal amount
