Determination of air properties is the mainstay of the science of psychrometry. Psychrometry is the branch of science and enginnering which mainly deals with the determination of physical and thermodynamic properties of gas-vapor mixtures. Application of psychrometry plays dominant role in heating, ventilation and air-conditioning (HVAC) industry and in water cooling requirement.
There exist well established fundamental and empirical relationships to determine various properties of moist and dry air as mainly per guide lines provided by ASHRAE (American Society of Heating, Refrigeration and Air-Conditioning Engineers). However for day to day engineering work, calculation from fundamentals and empirical formulae becomes too tedious. Like in many other subjects, engineers and scientists have traditionally taken help of printed psychrometric charts for many decades. By using such charts one can easily find out various properties of moist air with few input parameters.
Psychrometric charts are theoretically pretty accurate, but reading of such charts and subsequent determination of various properties from them generally lead to some errors, although minor in nature, because of very natural human limitations. Moreover, very nature of psychrometric charts makes the reading of the same from printed version makes it cumbersome.
Advent of electronic computer, especially personal computers, has made a sea change in this regard. Cute standalone software now-a-days make things very convenient and allow us to determine the properties of air without the help of printed charts. In these software typically two input parameters and the atmospheric pressure is provided as input and other properties are instantly calculated as output. The error involved in reading the printed chart is almost totally eliminated. It can be readily understood the utility of such standalone software in field of psychrometry.
However, the study and understanding of the psychrometric chart can never be undermined in the learning stage and even in the application stage. Concept of the variation property parameters with respect to one another is a must for all engineers and scientists who are any linked with the subject. The psychrometric chart as a whole represents relationship of various properties of the moist and dry air in one compact plane.
We are fortunate that application specialists have successfully created good software for instantly generating tailor made psychromeric chart software right on the computer monitor. These software generally provides following features: a) Can be drawn for any atmospheric pressure b) Can be drawn for any selected range allowing the chart to be used as blow up c) property lines can be drawn as per user’s choice by keeping the chart uncluttered d) can locate any point on the graph with user input parameters e) can solve air mixing problems and draw the lines on the chart f) can display and save property data of any point or mixing problem thus making standalone property software (described earlier) redundant g) can save and print charts any time as per user requirement thus making commercially printed bulky charts obsolete.
Internet user can easily find such software in the net. But before procuring one must verify that it provides all the functionalities as described above vis-à-vis its price. Some software provides all functionalities but charge too high a price and some do not even provide all functions.
Psychrosoft software
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