![]() It can be very helpful in troubleshooting and finding solutions to greenhouse or livestock building environmental problems. It was the time when telephone connections and radio were being started, so.Psychrometric Chart and Air CharacteristicsĪ psychrometric chart presents physical and thermal properties of moist air in a graphical form. In order to understand that the time difference between the appearance of the three diagrams was not great for the communication conditions of that time, we should remember that it happened less than a hundred years ago, when people communicated only in writing, using the postal services, mail first carried on horses or by ships, rare railroad traffic-anyway, all much slower than nowadays. ![]() Carrier's was the first to be officially published in 1911, Ramzin's in 1918, and Mollier's in 1923. The three diagrams were published within a period of 7 to 12 years. ![]() Ramzin's diagram was constructed similarly to Mollier's but was originally adapted to processes oriented toward the drying processes. So when these two diagrams are compared, one is to be viewed as a mirror image or, if on a slide, it should be viewed from the back and rotated. The Carrier diagram is left-oriented and represents a system of air humidity content (x) dependent upon the temperature (t) and enthalpy (h). The Mollier diagram is on the right side, with temperatures (enthalpy) on one axis and humidity content on another axis. ![]() The Mollier diagram is different from the Carrier chart in the coordinate system display. In Central Europe, the diagram or chart is called "the humid air Mollier diagram," and in Russia, "Ramzin's diagram." In the USA, it is called "the psychrometric chart" by W. There, thermodynamic changes to the final state may be precisely defined and marked during preheating, humidifying, drying, and, finally, heating and cooling, and also during the process happening in the controlled room when the air usually makes up the heat losses or neutralizes heat gains. The diagram was named Mollier's diagram by Europeans, Carrier's psychrometric chart by English-speaking nations, and Ramzin's diagram by Russia and the former Soviet Union as well as by Eastern countries.Īir-conditioning calculations are based on a diagram where the complete process of change in air treating or air handling may be presented, with all the conditions through which the air passes, from its outside state to its relocation into the air-conditioned space. It does not matter who was first or who was last all helped thermodynamic engineers in their realization of AC systems, presenting them with a diagram making it easy to calculate and analyze the air-conditioning process. It was a difficult time for close dialogs and exchange of information, but still it happened that three men, nearly in the same time, made the same contribution to the science and art of HVAC & R: namely, Carrier in USA, Ramzin in Russia, and Mollier in Germany. It is interesting that three men got the same idea in three very different locations of the globe, at a time when there were no radios, good phones, or electronic connections. The psychrometric diagram, or diagram of humid air, was established by three authors in a period of 12 years, very possibly independently from one another.
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