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What is a Psychrometric Chart?

Guillermo Martinez, an Applications Engineer for Polygon US, provides a comprehensive explanation of psychrometric charts, their significance, and how Polygon utilizes them in their work. Guillermo begins by introducing psychrometric charts as tools used to understand the properties and conditions of air, including temperature, humidity, and energy. He emphasizes that these charts are specific to…

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Guillermo Martinez, an Applications Engineer for Polygon US, provides a comprehensive explanation of psychrometric charts, their significance, and how Polygon utilizes them in their work.

Guillermo begins by introducing psychrometric charts as tools used to understand the properties and conditions of air, including temperature, humidity, and energy. He emphasizes that these charts are specific to certain conditions, such as elevation, which affects air pressure and alters the properties of air.

The video focuses on understanding the components of a psychrometric chart. Guillermo explains the x-axis, which represents the dry bulb temperature, the y-axis, which represents the grains per pound or humidity ratio, and the curved lines indicating relative humidity levels.

Guillermo demonstrates how the chart enables Polygon to determine their targets and understand the relationship between outside weather conditions and the desired internal environment. Through psychrometric chart generating software, they overlay weather data accumulated over many years to visualize worst-case scenarios and align them with the desired indoor conditions. This allows Polygon to determine the starting point and make informed decisions based on client specifications or material requirements.

He highlights a typical target of 75 degrees and 50 percent relative humidity, showcasing how this point on the chart provides additional information, such as the grains per pound. Guillermo stresses the importance of considering outside weather data, demonstrating how it influences the project. He explains that Polygon designs systems to manipulate the outside air and achieve the desired indoor conditions.

The video emphasizes the complexity and value of psychrometric charts in understanding air properties and planning environmental control solutions. Guillermo assures viewers that Polygon is ready to engage in detailed discussions with clients, tailoring explanations to their specific needs.

Video TranscriptExpand ↓

Hello, everyone. This is Guillermo Martinez, applications engineer for Polygon US, and today we're going to be discussing psychrometric charts, what they are, how they work, and why we have polygon use them. Let's look at a psychrometric chart here. I just wanna highlight that this is a chart specific for c level. These charts all change depending on elevation, which changes pressure, and therefore or we see changes in the properties of air. So going back to the definition of what these charts are, we're We're talking about a tool used to understand the different properties and conditions of air. These properties are known as temperature, humidity, energy, among some others. And through those properties, we can find we can do different calculations about what our solutions or on our system that need to be able to do to accomplish. Certain things. So to first understand the chart and what it's describing, let's look at the x axis down here. The dry bulb temperature. This is the temperature that we feel that we talk about with people when we're hot or we're cold. And we can see it increasing from left to right at the bottom. Next, I would want to bring your attention to these curved lines, the relative humidity lines, pretty straightforward. They describe the relative content of humidity in the air at the given temperature. And then on the y axis, this, we have the grains per pound or our humidity ratio and we can think of this as a more physical rather than relative, measure of the content, the moisture content in air. So like any two dimensional chart with two pieces of information from different axes, we can find any one point within the chart. So, this chart allows Polycom to determine what our targets are gonna be and what we're going to be working with. What I mean by working with is What our starting point is based on outside weather versus where we need to be internally in the space given client specifications or even material specifications. So, through psychrometric chart generating software, we're able to portray out side weather data that's been accumulated over a hundred years through ASHRA, we can portray that data here in the chart, so we can see the chart and the weather together so that we can see that worst case scenario and line it up with the inside target. So a typical target for us in a lot of the projects we're involved in could be seventy five degrees, which is this line that I'm highlighting, along with fifty percent relative humidity, which is this line right here. So I'm just going to highlight a portion of that line or try to. And here's an marking that spot. We can pull out a lot more information from knowing this spot like, for example, the grains per pound, if we draw a straight line over to the right, sometimes that's important, sometimes it's not. But I just wanted to show you how we get more information just from knowing two pieces of of information on two different axes. But along with the inside target, it's important that we understand, as I said before, the outside weather. So this will show us with that weather data overlaid on here. It would show us that the maximum weather in any one location might not exceed a hundred degrees for the duration of our project there. It also might show us that it gets all the way up to a hundred and fifty grains right here. Which happens to be on that same fifty percent relative humidity line. It also would show that we have forty five degrees and potentially a hundred percent relative humidity, which is this top line, right here, the edge of the chart, it might show us that this is as cold as it gets, so now it's up to Polycom to come up with a system that can bring the outside air and manipulate it, so that it becomes this inside. And then so is the opposite on the on the right hand side of the chart when we're cooling. We want to do through our system, whatever it needs to do, so that the inside ends up right here where I drew the first x. So again, as you can see there's a lot of information and a lot of conversation that goes on around one of these charts. We are happy to discuss with our clients every implication with what goes on in the chart. And as I always say, we're happy to walk as far or as little as the client wants us to in these explanations because they are somewhat So hopefully you enjoyed that short conversation and we can keep going further next time. Thank you.

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