Weird zone mean air temperature in Case 600 FF of the Building Energy Simulation Test in energyplus [closed]

asked 2019-12-08 21:17:41 -0500

oscircle gravatar image

updated 2020-01-07 17:02:30 -0500

In recent times, I want to run some standard cases in "EnergyPlus Testing with Building Thermal Envelope and Fabric Load Tests from ANSI/ASHRAE Standard 140-2007". These cases are used for comparison of heating and cooling load provided by different softwares. You can download the PDF file from this website. http://www.labeee.ufsc.br/sites/defau...

I downloaded Case 600FF and Case 900FF from this website. (https://github.com/NREL/BESTEST-GSR) This website says its purpose is to generate BESTEST (Building Energy Simulation) test case models, run simulations, and populate data for ASHRAE Standard 140 reporting spreadsheets for EnergyPlus based whole building simulation tools. So I just used the default idf file the website provided.

Here is the weird thing to me. I didn't change any setting. But the simulation result shows the zone mean air temperature in Case 600FF even increases to 60℃ in winter during the daytime. It seems unreal. Could anyone tell me some possible reasons? Now I think the idf file from the website is valid. Here is the result. The red line shows the temperature of Case900FF, and the blue line is the temperature of Case600FF. C:\fakepath\airtem Case600FF Case900FF.png

I have something to explain about these two cases. Their setting is similar except for the thing that Case 600FF is of lightweight construction but Case 900FF is of heavyweight construction. Especially, they have no HVAC equipment for mechanical heating and cooling. Here is the geometry of the building used in both two cases. C:\fakepath\Case 600FF.png

I have a guess. Is it the big windows facing south of a large area that cause weird results? Because during the daytime, there is abundant solar radiation. In addition, the building in Case 600FF consists of lightweight walls, floor and has no HVAC equipment. When solar radiation is abundant, the indoor air temperature may increase to 40~50℃. Is it correct?

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Closed for the following reason the question is answered, right answer was accepted by oscircle
close date 2019-12-09 21:34:46.165276