Question-and-Answer Resource for the Building Energy Modeling Community
 | 1 | initial version |
There is a better option calledZoneHVAC:UnitHeater in EnergyPlus - and also OpenStudio - that would serve this purpose.
You go to the Thermal Zones tab, and drag and drop from "Unit Heater", in your case either the "CV Unit Heater HW" or "VAV Unit Heater HW". You can then attach the coil to the plant loop of your choosing. You can enter the W for the heating coil (instead of UA), and the maximum air flow rate in the ZoneHVAC component.
Model a secondary plant loop, connect it to the boiler plant loop with a HeatExchanger:FluidToFluid.Add your unit heaters to the demand side of the secondary plant loop, and on this loop make your pump run all the time.
Pipe - Indoor and Pipe - Outdoor would serve here. Note that I wouldn't encourage you to model indoor pipes that are in conditioned zones especially if you have a lot of them: it'll get too complicated for little reason. Stick to modeling indoor pipes in unconditioned spaces and outdoor pipes. You can also preprocess your stuff to calculate an equivalent pipe instead of entering dozens of them.
