I have to admit I'm slightly confused here, as I am seeing contradicting information on how to model solar collectors in EnergyPlus and OpenStudio.
On one hand, everything on EnergyPlus side seems to imply the solar collector must be on the demand side of the plant loop.
- In the I/O reference guide, there is a section Solar Collector Heating System Plant Connections, which says the following:
The solar collector must be connected on the demand side of the plant loop. Multiple collector modules can be combined in series and parallel using the normal plant connection rules. The supply side of the plant loop should contain a water heater with the solar collector loop connecting to the Source Side Inlet and Source Side Outlet nodes
- The example files such as
SolarCollectorFlatPlateWater.idfdo implement it this way.
On the other hand, there are numerous questions about OpenStudio here that show the solar collector on the supply side, for example Active indirect solar hot water collector modeling and solar collector panel to DHW.
So I could see two explanations, which one is right?
- The I/O reference guide and example files are outdated, and it is possible to put it on the supply side of the plant loop
- OpenStudio is doing some "magic" in Forward translation, to create a plant loop where it's on the demand side (a cursory look at source files didn't reveal anything obvious...)
