Structural Drying >> Ceiling Leak Mold From Pipe Break

However, this relationship could not be proven by experimental investigations on other materials. Scheffler (2008)showed measurement results for a calcium silicate insulation material and a ceramic brick. Both materials have a distinct first drying phase. All results indicated a linear relationship between first drying phase duration Ceiling Leak Mold From Pipe Break and sample height. 

Onechart of these results is shown in Figure 2 at the right. The studywas performed with samples of different diameter and heightand for different vapor transfer conditions to study these influences as well. All results showed a perfectly linear relationship.These discrepancies stipulated an additional study toinvestigate how these differences can occur Ceiling Leak Mold From Pipe Break and understand what influence on the drying process might have caused them. 

ANALYSIS OF THE INFLUENCES ON THE DRYINGThe analyses compared measurement against simulationresults, one-dimensional models against three-dimensionalreality, Ceiling Leak Mold From Pipe Break and different materials with different sample heights.From this, a set of possible influences to investigate wascompiled:1. Influence of heat and vapor transfer coefficients.

Influence of the applied material Ceiling Leak Mold From Pipe Break and simulation model 3. Influence of accounting for or neglecting the threedimensional heat transport 4. Influence of the initial moisture content 5. Influence of the investigated sample heights Investigating these would shed light not only on theparticular discrepancy between measurement and simulation,but also on the influences of the drying experiment in general.

Heat and Vapor Transfer (1)The heat and vapor transfer conditions significantly influence the slope of the drying curve during the first drying phase, Ceiling Leak Mold From Pipe Break and by that also the first drying phase duration. This becomesclear when looking at the left chart of Figure 3, where simulation results of a ceramic brick drying are shown. 

The only changed parameter is the vapor transfer coefficient ß. Not only the first drying phase duration, Ceiling Leak Mold From Pipe Break but also the moisture content at its end are influenced by the transfer conditions at the material surface.

(1)where LE = Lewis number for water vapor given with LE = 0.87 m = dimensionless parameter, Ceiling Leak Mold From Pipe Break according to Baer and Stephan (2003), m = 1/3 = heat transfer coefficient= gas constant for water vapor= Kelvin temperature= specific heat capacity (isobaric condition)= density of air.

The simulation study of Krus et al. (2007) used the analogy between heat and vapor transfer coefficient, Ceiling Leak Mold From Pipe Break also known asthe LEWIS-relation (Equation 1). Evaluation of dryingmeasurements indicated that this relation does not always hold for experiments with higher airflow velocities. However, this is only important if experiment and simulation are compared.

For a simulation study using the same heat and vapor transfercoefficients in all cases, Ceiling Leak Mold From Pipe Break this does not lead to different results.Material and Moisture Transport Model (2)The quality of the applied material functions is an often disputed problem whenever numerical simulations are carriedout. The approximation quality of the material functions iscrucial for any calculation where the results need to be correct.

To exclude any such influences from the discussion, Ceiling Leak Mold From Pipe Break drying simulations were performed with two different material andtransport models according to Krus and Holm (1999) andScheffler and Plagge (2010).The material functions were adjusted according to thesemodels to measured brick data. 

Drying simulations wereperformed while the liquid transport function was slightlyvaried (for both the whole function Ceiling Leak Mold From Pipe Break or only in the lower moisture content range). These calculations produced different but very similar results. All of them showed a linear dependencebetween first drying phase duration and sample height. 

Therefore, the applied model and the approximation quality do notexplain the differences and are of minor importance here.Three-Dimensional Heat Transport (3)Due to the cooling effect of evaporation, Ceiling Leak Mold From Pipe Break the drying surface of a material sample is significantly colder than thesurrounding air. 

As the sample has a finite dimension, heat isnot only transferred from the top (air) and bottom (materialsample) surfaces, but also from the lateral sides of the sample.This leads to a distinct temperature distribution at the drying surface, Ceiling Leak Mold From Pipe Break which in turn causes a vapor pressure distribution there. Consequently, the evaporation rate is not the sameeverywhere at the drying surface.

As the lateral heat flow increases the temperature, thiseffect increases the evaporation rate and, hence, Ceiling Leak Mold From Pipe Break the dryingspeed. This becomes visible in the right-side chart of Figure 3.Here, radial-symmetric three-dimensional simulation resultsfor a ceramic brick drying are displayed. The only variedparameter is the sample diameter, where one-dimensionalcorresponds with an infinite sample diameter.

The influence is clearly visible. This effect is particularlyimportant when comparing experimental data with simulationresults, Ceiling Leak Mold From Pipe Break and the main reason why cylindrical samples should beused for drying experiments (Scheffler and Plagge 2005). The simulation results according to Krus et al. (2007)were done one-dimensionally. 

This might lead to deviationsbetween measured Ceiling Leak Mold From Pipe Break and calculated drying curves, but it doesnot change the relationship between first drying phase duration and sample height from linear to square root. The influence of three-dimensional heat transport is therefore not thereason for the observed deviations. Initial Moisture Content (4)The initial moisture content has a significant influence onthe first drying phase duration. 

The more water needs to beevaporated through a certain surface, the longer it takes.Figure 4 illustrates this with simulation results of a ceramicbrick drying starting from different initial moisture contents.As the initial moisture content is very important for thefirst drying phase duration, Ceiling Leak Mold From Pipe Break it should receive special attention.In order to make results comparable, all investigations shoulduse the same initial moisture content. 

For a simulation, any moisture content can be adjusted and assigned in an even distribution. For an experiment, Ceiling Leak Mold From Pipe Break this is not easily possible. The experimental drying normally starts after a completed water absorption experiment. 

This means that the mean moisture Ceiling Leak Mold From Pipe Break content that is established inside the sample will rangebetween capillary and effective saturation. A drying simulation should therefore start from the moisture content reachedafter a water absorption experiment.

How To Keep Animals Out Of Sheds

Trapping and translocation operations. Permittees wishing to trap and translocate Canada geese must comply with the following procedures: a. Permittees must obtain written permission from the biologist responsible for the county in which the trap and translocation operation is proposed for every sit  read more..

How To Remove Flood Damage Debris

General Conditions and Special Provisions Project Schedule: Prepare a time schedule beginning with start of mobilization through completion of demobilization. Provide a timeline for all major items of work. Site Specific Injury and Illness Prevention Plan (IIPP): Prepare a site specific IIPP which  read more..

How To Secure Windows For A Hurricane

To prepare for a hurricane, you should take the following measures: To begin preparing, you should build an emergency kit and make a family communications plan. Know your surroundings. Learn the elevation level of your property and whether the land is flood-prone. This will help you know how your pr  read more..

Childhood Lead Poisoning Prevention

Childhood Lead Poisoning Prevention Program The elimination of childhood lead poisoning has been one of the most effective public health campaigns of the 21st century, but much work remains to be done. The Arizona Department of Health Services (ADHS) remains committed to preventing new cases of chil  read more..

How To Keep Animals Out Of AC Duct Work

Executive Order 12342, January 24, 1982, permits the use of chemical toxicants registered by the Environmental Protection Agency for predator damage control on federal lands. 3. Department of Agriculture Regulation (DR) 9500-4 (2601.2) requires Department of Agriculture programs to include measures   read more..

Electronic Systems In Flood damaged Buildings

Electronic Systems in Flood-damaged Buildings
Question: Do electrical systems and equipment submerged through flooding have to be replaced? Answer: Floodwaters are not just water; the water may also be contaminated with chemicals, sewage, oil and other debris. When the floodwater   read more..

Radon Gas

What is Radon gas? Radon gas is a gas produced by the radioactive decay of the element radium. Radioactive decay is a natural, spontaneous process in which an atom of one element decays or breaks down to form another element by losing atomic particles (protons, neutrons, or electrons). When solid ra  read more..

Emergency Board Up_Alternative To Boarding Up Wind

This handbook provides a brief overview of the types of disasters posing a potential threat to staff. NOTE: This handbook does not contain emergency procedures for cultural items. These emergency procedures are intended to assist individuals in understanding what to expect and what to do initia  read more..

Mold Caused By Basement Flooding

FREQUENTLY ASKED QUESTIONS ABOUT FLOODING, MOLDS, AND HEALTH Q. What does "thoroughly washed" mean? A. Washed in hot, soapy water. Q. What should I do about the floors, walls, and ceilings? A. Vinyl floors, drywall, insulation, and in some cases ceilings should be removed Mold Remediation Mold Caused By Basement Flooding and replaced  read more..

Lead based Paint Can Cause Lead Poisoning

The employer shall make available upon request all records required to be maintained by this subsection to the Chief and the Director for examination and copying. (B) Environmental monitoring, medical removal, and medical records required by this section shall be provided upon request to employees,   read more..