Even though it is a limited version, it is still a very useful tool since it allows you to plot points, read the parameters associated with the location of your cursor, create a .pdf of your chart, and copy the image to your clipboard for use in a report or presentation.
For this post, I thought I would focus on what the basic version of the chart can do by using an example. The links below will jump you to topics of interest, since this is another long post. The Return to Contents like at the end of each section will bring you back here.
HDPsyChart FULL Version 20
Even in the basic version of the chart, there are a number items you can manage in the psychrometric process window, including naming a point, controlling where the label sits relative to the point, the air flow you are dealing with for your process and its units of measure, and the type of process.
If you upgrade to the full featured version of the chart, you can do this very quickly as a part of the tool by simply drawing a SHR line through the space condition using the Constant Line Control tool, which is one of the many tools you get if you upgrade the basic chart. If we did that for an ASHRAE space with a SHR of .8, it looks like this.
To finish this post, I am going to make an addition to our little HVAC system that will make it more realist. Specifically, I am going to add ventilation air from outside and then use that to demonstrate how you plot a mixed air condition on a psych chart. I will use the Pro version of the chart to make it a bit faster for me and to illustrate a few other features of that chart.
With the basic version of the chart, you would need to look up the outdoor design condition in some other resource, like the ASHRAE Handbook of Fundamentals or an internet search. But if you have upgraded to the professional version of the chart, that information is built in as a tool you can open up, specifically, the HDClimatic Tool, which shows up in the drop-down menu under Tools.
The data behind the tool is the ASHRAE data so it covers many, many locations through-out the world. Here is what that looks like for St. Louis, MO from my professional version of the PG&E psych chart.
Specific humidity is a measure of the absolute amount of moisture in the air. Common units include pounds of moisture per pound of air and grains per pound, which is what the professional version of the PG&E chart defaults to. You can change the units along with many other settings like colors, line weights, etc. using the Chart Profile Control tool on the Settings drop down menu in the professional version of the chart.
But, the professional version of the PG&E psych chart makes the mixing analysis even easier. The reason is that the professional version of the chart gives you quite a few more processes to chose from in the Process column of the Psychrometric Process window, including an air mixing process. This is what that looks like.
I should point out that in both versions of the chart, you can drag the side of the Psychrometric Process window to make it wider and see all of the psychrometric data for each point in the table, which is what I did to make the image above.
Hopefully, at this point, you have seen that either version of the PG&E chart can be quite useful if you are working with HVAC systems and trying to understand what is going on in them. If you do that sort of thing a lot, then the professional version of the chart will probably pay for itself by streamlining your process. Plus, the professional version includes a number of very useful tools that I have not used up to this point. So, I will close by showing you a few of the ones I use the most.
One of my favorites is to do a bin plot of the climate data for a particular location on the chart. The professional version of the chart has the Typical Meteorology Year 2 and 3 files (TMY2 and TMY3 files) built into it. You can access that data from the Analysis drop down menu using the Open a Weather Data File tool. If we do that for the HVAC process we just analyzed, it looks like this.
If you look at the full file, you will discover there is a line in it for each hour of the year with all of the associated weather data. If you save this file as an Excel workbook, you will then be able use things like the KW Engineering Get Psyched functions and basic HVAC equations to perform hour by hour energy calculations against a normal climate year.
There is a motor heat calculator included in the Pro version of the chart that tells you what the temperature rise will be across a fan due to the fan heat and the motor efficiency losses into the air stream. In this example, I entered the flow rate and fan static pressure and static efficiency and the motor efficiency and the other metrics were provided by the calculator when I clicked on the Calculate button.
You may have already found your answer, but the specific version of the Hands Down chart that I have (in addition to the Pacific Energy Center customized version Ryan Stroupe procured from Hands Down Software) is version 7.9.4. That may be the same thing as what you are calling version 7, since that is how it shows up on the page for the software; i.e. it just calls it version 7, even though the current version is 7.9.4.
That said, the version I have includes a number of tools that may or may not be in the version you have, including energy recovery wheel analysis. So, assuming the things you listed are features you were looking for, I think that they are addressed by the version that I have.
The climate data in the version I have is still based on the TMY2, TMY3, CWEC, and IWEC climate data. But again, for what I am doing (projecting potential savings for EBCx measures), that is generally good enough, especially once you understand the vagaries of TMY data. If I am looking backwards in time, I use actual data for the interval in question. There are several ways to get it, which I discuss in this blog post. 2ff7e9595c
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