How do I use the SurfaceProperty:SolarIncidentInside feature properly?

asked 2016-06-28 02:39:54 -0600

kontante

51 ●1

updated 2016-10-21 12:34:08 -0600

__AmirRoth__

4436 ●5 ●17 http://bleedinggreenna...

I used the SurfaceProperty:SolarIncidentInside object to calculate the effect on the building energy balance of reflected sunpatches on the ceiling inside a rectangular room. Using Radiance I computed the schedule of the solar incidence values for that surface and then fed it to EnergyPlus for simulation. I get this warning:

** Warning ** Zone THERMAL_ZONE does not have all surfaces scheduled with surface gains.
 **   ~~~   ** If at least one surface in the zone is scheduled with surface gains, then all other surfaces within the same zone should be scheduled as well.
   **   ~~~   ** Surface 245779 does not have scheduled surface gains.
   **   ~~~   ** Surface 5B30C6 does not have scheduled surface gains.
   **   ~~~   ** Surface C0C614 does not have scheduled surface gains.
   **   ~~~   ** Surface THERMAL_ZONE_WINDOW_LOWER does not have scheduled surface gains.
   **   ~~~   ** Surface THERMAL_ZONE_WINDOW _UPPER does not have scheduled surface gains.
   **   ~~~   ** Surface DC934B does not have scheduled surface gains.
   **   ~~~   ** Surface AE57E2 does not have scheduled surface gains.

Does this message means that in order to implement the SolarIncidentInside object I must create schedules for all the solar gains of the surfaces of the space?

If only one surface is scheduled does EnergyPlus also take into account the solar gains from the other surfaces that are not scheduled during simulation?

answered 2016-07-01 09:49:10 -0600

kwalkerman
1472 ●8 ●9

updated 2016-07-01 09:49:45 -0600

The short answer is that I believe that having a SurfaceProperty:SolarIncidentInside object inside a zone triggers EnergyPlus to turn off it's internal calculation for solar gain on surfaces.

The long answer (and why I believe what I stated above):

I ran a quick test on the example file for this object. The example file is "CmplxGlz_SchedSurfGains.idf"

For the test, I deleted the SurfaceProperty:SolarIncidentInside object for surface "ROOM102 FLOOR". If you look at the output file "CmplxGlz_SchedSurfGains_delete_surface.csv" - "ROOM102 FLOOR" reports 0 for all hours for Surface Inside Face Absorbed Shortwave Radiation.

I then further modified the file to delete all SurfaceProperty:SolarIncidentInside and ComplexFenestrationProperty:SolarAbsorbedLayers objects. Running this file resulted in Surface Inside Face Absorbed Shortwave Radiation reported for all faces, except for "ROOM102 South Wall". I'm pretty sure that "ROOM102" South Wall is not reporting Surface Inside Face Absorbed Shortwave Radiation due to the zone geometry.

The files can be viewed by following this Dropbox Link.

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To add to this post. I found that Solar Heat Gain can still occur through a window even with the use of SurfaceProperty:SolarIncidenInside. I changed the BuildingSurface:Detailed to NoSun to alleviate this behavior. What was confusing to me was that the EnergyPlus documentation say that the EnergyPlus calculations are no longer used. However, I observed that even with the SurfaceProperty:SolarIncidentInside for all surfaces set to 0 I was still receiving some energy in the Surface Inside Facade Absorbed Shortwave Radiation. After changing to NoSun I no longer receive any.