Creating a wind rose based on conditional dry bulb temp.

Replies to This Discussion

Permalink Reply by Abraham Yezioro on November 5, 2014 at 8:16am

Ludvig,

You should look for the LB examples. Check the one that Daniel Nielsen provided there (Ladybug-02_Analyze-WindRose+WeatherData_20140912).

You'll find the answers there.

-A.

Permalink Reply by Chris Mackey on November 5, 2014 at 10:31am

Thank you for the question, Ludvig and thank you for the good response, Abraham.

Ludvig, I also cover how to use conditional statements in the getting started with Ladybug tutorial series:

https://www.youtube.com/playlist?list=PLruLh1AdY-Sj_XGz3kzHUoWmpWDX...

There is a specific video on the wind rose that shows you how to use wind rose conditional statements:

https://www.youtube.com/watch?v=G27WWkqlKxA&index=5&list=PL...

I realized that the heating degree hours method might not be as intuitive so I have attached an example showing you how to do that.

-Chris

Attachments:

• Wind Rose Conditional Statement.gh, 89 KB

Permalink Reply by Abraham Yezioro on November 5, 2014 at 11:09pm

Nice example,

Just a fix: You need to connect the hourly_coolingDegHours to the annualHourlyData_ (instead of hourly_heatingDegHours). At the end both options will yield the same result.

-A.

Permalink Reply by Ludvig Haav on November 7, 2014 at 7:38am

Thanks! This was very helpful. your video helped me understand why i kept getting the conditional statements wrong.

I do have a small follow up question out of curiosity though.

If i would want to calculate what wind directions that lead to the most heatloss i would have to calculate a wind chill effect neglecting the RH. Temperature, air specific heat, wind speed and heating degree hours all in one equation. Is this doable? Is it relevant? It would lead to a windrose that is very graphic and easy to understand i think.

Permalink Reply by Ludvig Haav on November 7, 2014 at 8:24am

oh wait, I guess such a graphical display of cooling effect cannot be calculated without taking U-value into consideration. 5ms wind and 10ms wind will probably have increasingly similar cooling effect as u-value increases. this is starting to get complicated.

Permalink Reply by Chris Mackey on November 7, 2014 at 10:31am

Ludvig,

You could set up a Honeybee Energy simulation and plug in the "infiltrationLossGain" to the annual hourly data of the wind rose.  That infiltration loss/gain will show you the hourly heat gained or lost to the zone by infiltration, which seems to be what you are interested in.  You could then use the conditional statement to select the hours when this infiltration loss is the worst.  That's the best way that I would think of it.

-Chris

Permalink Reply by Ludvig Haav on November 7, 2014 at 10:36am

I get what you´re saying. Thanks for the input!