I have officially relased the 0.1.0 version of an online psychrometric chart. You can go ahead and check it out at psychrochart.com. The source code is hosted on GitHub here.

Here’s a couple reasons why I think it’s a cool and useful project:

  1. The chart is completely dynamic. If you modify the total atmospheric pressure, you will immediately see the chart update accordingly.

  2. The chart looks great (totally unbiased), using d3.js to produce the SVG. A great deal of care went into making the chart look good, even under a variety of different inputs (think calculating derivatives of all those constant property lines).

  3. The site is completely free and open source. I hope people find it useful and also can help contribute going forward.

  4. A goal of the page is to use as few dependencies as possible. Right now, it uses d3.js, knockout, and SaveSvgAsPng. The page should be light and load quickly.

  5. No Ads.

  6. It’s built with just HTML, JavaScript, and CSS. No server-side code. There will be standalone releases going forward so you can run it even without an internet connection.

Obviously, it’s not fully featured yet. Some items of priority to add:

  1. Displaying the other calculated properties for the entered states.

  2. Use of other properties besides humidity ratio to fix the state.

  3. Allowing process lines to be drawn.

  4. SI units. For those 7+ billion people that actually use the better system of units.

  5. Customize colors.

Of course, since this is now public, feedback from the public is welcomed.