Question-and-Answer Resource for the Building Energy Modeling Community
 | 1 | initial version |
I am not sure how this works in OpenStudio but we model radiant ceilings a lot in EnergyPlus (the background engine). In EnergyPlus you need to name the ceilings which are radiant, they have a special construction called construction:InternalSource. These radiant ceiling surfaces need to be put into a surface group (ZoneHVAC:LowTemperatureRadiant:SurfaceGroup, if you have more than one surface per zone that is a chilled ceiling. In the surface group EnergyPlus asks that you specify the surface name of your chilled ceiling and the percentage or fraction that each surface takes of the overall area in the zone that is chilled ceiling. So if you have two chilled ceilings which have an area of 20m² and 30m² respectively then the fraction for the first is 0.4 and for the second 0.6, all fractions must add exactly to 1 for each surface group.
This surface is then put into the radiant ceiling object, ZoneHVAC:LowTemperatureRadiant:VariableFlow. If there is only one chilled ceiling in your zone you can just put the surface name in there.
If you have pulled the idf out and opened it in E+ then these are the two places to look to check for these things: ZoneHVAC:LowTemperatureRadiant:SurfaceGroup ZoneHVAC:LowTemperatureRadiant:VariableFlow
