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Disaster Advice Glossary
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Disaster recovery and restoration can be veiled in mystery to the many who have not undertaken specific training. This glossary explains technical terms to assist both report writing and the understanding of those technical terms so often misunderstood.
Definition
| Adiabatic: |
Changes in matter (material) which take place without the transfer of heat. A condition in which there is no change in the measurement of temperature (where there is no gain or loss of heat), but there can be a change involving the expansion or contraction of a material without the loss or gain of heat, the change of entropy. An example is the curing of concrete or mortar, or in a water damage building where wood floor expand because of water and not a a result of heat. Education Note: in other words, when heat is added or withdrawn from a material the material generally experiences changes in temperature, pressure and volume, and sometimes a change of its physical makeup. These changes severely involve the absorption or the release of energ, which may be regarded respectively as positive nergy increments, and there is an algebraic sum of which is equivalent to the quantity of heat either supplied or removed id the material could be provided with perfect thermal insulation so that no heat could enter or leave it, then any change requiring energy, which might take place within the material, would necessarily be effected at the expense of energy by the other internal changes. But a rise of temperature might be caused by heat generated in compression. processes of this sort, unaccompanied by any transfer of heat across the insulating boundaries of the material, are said to be adiabatic. In reverse, the adiabatic processes are also isentropic, that is, they take place without change to entropy. (A hardwood floor expands due to water as a liquid of vapour that cause the cells to dilate, resulting in wood expansion, and over time, the wood releases the water and vapour, resulting in the hardwood floor to relax. Was there a change in temperature (heat) which caused the wood to expand or contract? Sometimes not. The same is true for wet walls and partcleboard damage from contact with water, resultingin the swelling and damage to the material). Adiabatic processes, though hardly realized in practice by a water damage or restorative drying technician, are often considered in thermodynamic reasoning. See Entropy |
| Adiabatic Processes in Atmosphere: |
When a parcel of air is moved from one atmosphere to another in a building, with respect to the ambient air, in such a manner that energy does not flow across boundaries, thermal changes taking place are said to be adiabatic changes. Education Notes: Any process in the buildings atmosphere occurring adiabatically is known as an adiabatic process. In water damaged buildings, for example, temperature and humidity are important. The adiabatic process during which the air involved in non-effected areas (the parcels of air remaining unsaturated during the drying process) are relatively simple and they do not effect the humidified air parcel directly. the adiabatic processes involving condensation or evaporation through dehumidification are considerably complicated by heat of condensation. Monor temperature and humidity changes within static air may not be important, but the same changes in moving air may be significant. This method of measurement of heat or the absence of heat in a water damaged atmosphere of a building, for example, is based on the first law of thermodynamics. Author's Note: The author placed this brief discussion about adiabatic processes purposely to bring attention to the reader, the seriousness about understanding building and restorative drying processes and methods and the dynamics required to dry a wet building properly. It is also reasonable to help technicians recognise that the use of a moisture probe or a moisture stick is only the tip of the iceberg, when attempting to understand physics and natural laws of thermodynamics. The author is not attempting to have the subject fully discussed, but is bringing the subject up for the reader to investigate further. See Adiabatic, Entropy |
| Air Dynamics: |
The ability of air to have energy and force in motion. The transfer or induction of air from one area to another through pressure, temperature or humidity. Air dynamics are in contrast with static air. Air dynamics can move airborne contaminates from or into porous materials. See Adiabatic, Air Movement, Air Pathway, Convection, Static |
| Cooling, Evaporative: |
Involves the adiabatic exchange of heat between air and water spray or wetted surface. The water assumes the wet-bulb temperature of the air, which remains constant during its traverse of the exchanger. |
| Evaporative Cooling: |
The adiabatic exchange of heat between air and a water spray or a wetted surface. In an HVAC unit, the water approaches the wet-bulb temperature of the air, which remains constant during its traverse at the exchanger. |
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