IICRC WRT Exam (2024/2025) | Actual Questions and Answers Latest Updated 2024/2025 (Graded, Exams of Biology

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IICRC WRT Exam ( 2024 /2025) | Actual Questions and Answers Latest

Updated 2024/2025 (Graded A+)

Moisture levels of ______% will support destructive wood (rot) decaying fungi to grow on wood surfaces. Answer ✔✔20% relative humidity Answer ✔✔Is the ratio of the moisture suspended in air expressed as a percentage of total moisture holding capaciry of that air at a given temperature. ACM Answer ✔✔Asbestos Containing Material Daily Humidity Record Answer ✔✔Occurring at least every 12-24 hours the recording the relative humidity and temperature to determine Grains Per Pound (GPP). Areas not directly wet will experience humidity elevation. Therefore... Answer ✔✔Technicians must isolate affected areas from non affected areas to gain best control of humidity. Vapor Pressure will always Answer ✔✔...seek a level of equilibrium within a confined space. How many grains are in a pound of air? Answer ✔✔ 7000 Humidity ratio/specific humidity Answer ✔✔The amount of water in the air (by weight) contained in the parcel of air. What is the goal for day 2 drying? Answer ✔✔To get the humidity under 70 to ensure mitigation. Dew point is also known as ___. Answer ✔✔saturation temperature or condensation The Dew Point Answer ✔✔the temperature at which the air becomes saturated with water vapor (100%RH) and condenses on the cooler surfaces.

Where does condensation moisture cause mold? Answer ✔✔Mold growth can occur in cold spots of homes and buildings where warm indoor air encounters cold outside air or vice versa. Fog Answer ✔✔When the air meets the dew point temperature. Dew Answer ✔✔The temperature at which condensation overwhelms evaporation. Why might condensation be bad? Answer ✔✔Condensation with a bio film (an organic film like soap or glue) present allows mold to grow in a variety of surfaces from plastic to glass. Biofilm Answer ✔✔Any organic substrate and bacteria that tends to encourage mold growth. Why are Thermal Cameras Important? Answer ✔✔Thermal cameras, along with other sensors can detect the moisture perimeter of wet carpet and cushion. vapor pressure Answer ✔✔A gaseous force exerted by the water vapor on its environment. When does evaporation occur? Answer ✔✔when vapor pressure of the ambient air (air in the room) is lower that the vapor pressure of the wet material. What else can increase evaporation? Answer ✔✔If the air has low Vapor Pressure (VP) and can be heated the added thermal energy (heat) will also increase the rate of evaporation. The potential for damage to hygroscopic material is... Answer ✔✔...greatest when Relative Humidity is over 70% Why is it imperative that the RH is lowered below 70% by the second day? Answer ✔✔RH over 70% for more than 48 hours can provide the right amount of water activity to promote mold growth.

Hygroscopic materials continue to absorb... Answer ✔✔...water vapor at a given temperature and relative humidity until they have reached equilibrium. Hardwood furniture in an extremely humid building may... Answer ✔✔...swell and release stains as the moisture content increase. Permeance Answer ✔✔ability of water vapor to pass through solid materials. Aka permeability. Items that have a perm favor or less than 1.0 are stated as moisture vapor barriers and Answer ✔✔Must be removed. Water as a vapor can... Answer ✔✔...pass through materials without wetting it Ventalation Answer ✔✔Opening a window and exhausting wet air on one side of a room and opening another allowing warm dry air to enter. Excellent way to "open dry." When is closed drying used? Answer ✔✔When the outside air is too wet or cold to aide in the drying process. Specifically if the outdoor humidity ration is higher than the indoor then a closed drying system is used. When using Refrigeration Dehumidification, the temperature of the affected area must be... Answer ✔✔...maintained as close to 80 degrees as possible. All other things being equal, the temperature that will increase the rate of evaporation the most is? Answer ✔✔80 degrees All conventional dehumidifiers and many of the LGRs do not operate efficiently at... Answer ✔✔Higher temperatures above 85 degrees.

What is the ultimate goal. Answer ✔✔Having the most efficient drying is the ultimate goal, as technicians incorporate the relationship of temperature, humidity, and air flow. Dehumidification Answer ✔✔The reduction of water vapor in the air. According to American Society of Heating, Refrigeration, and Air Conditioning Engineers (ASHRAE) the most acceptable indoor humidity range for health and comfort is... Answer ✔✔...between 30%-50% humidity. Refrigerant Dehumidifiers are most efficient... Answer ✔✔...in the 70-90 degree temperature range. The most efficient dehumidifier to use with warm conditions, high humidity, and porous materials is the refrigerant. Refrigerant dehumidifiers are not suited for... Answer ✔✔...professional drying as they are unable to operate efficiently at 70 degrees and below. CFM Answer ✔✔cubic feet per minute AHAM Answer ✔✔Association of Home Appliance Manufacturers What does AHAM do? Answer ✔✔Rates dehumidifier capacity by measuring water removal expressed in pints at 80degrees F and at a Relative Humidity of 60% per 24 hours. Conventional Dehumidifier Answer ✔✔A term given to a dehumidifier that do not have the ability to continue to remove water from the air as the air becomes drier. Conventional/LGR Dehumidifiers operate and revive water via... Answer ✔✔CONDENSATION as the warm air is drawn across cold coils and condenses.

When deploying the IICRC formula it often... Answer ✔✔...surprises many technicians how many conversational units are actually required for the initial start up drying process. Most are realizing that they are falling far short by guessing or hoping the have adequate start-up dehumidification. What is the benefit of a Low Grain Refrigerant (LGR)? Answer ✔✔A low grain refrigerant dehumidifier continues to remove significant water vapor below that of a conventional. Technicians must lower RH below... Answer ✔✔70% within the first 24 hours. The potential for damage to hygroscopic materials is greatest when... Answer ✔✔...relative humidity is above 70%