Modeling simple fans and fan-heaters in Openstudio

edit

Hi Graphus,

To your first question, are you just trying to capture the energy from running the fan? If so, I'd recommend adding it as an electric load, and giving it a schedule that has it turning on and off at the times you're expecting throughout the year. Since desk fans are usually driven by occupant behavior, you could look at using a schedule that follows occupancy loads or just use something as simple as the fans running all day and turning off at night. If you're just trying to capture energy, then using the power draw from the outlet will capture everything.

As for the space heater, the CV unit heater elec is what you want. Notice that after adding the heater to the zone and clicking it to edit it, even though the OS:ZoneHVAC:UnitHeater section mentions water coil info, if you scroll down there isn't a water coil object associated with the unit heater. You could hard size the Maximum Hot Water Flow Rate input to zero if that would make you feel better, but there isn't a water coil that can actually supply heat. The unit heater only has OS:Fan:ConstantVolume and OS:Coil:Heating:Electric objects that you can configure for it. TheUnitHeater objects in EnergyPlus and OpenStudio can take a few different forms, which is why you get some input overlap. I would recommend hard sizing the Nominal Capacity for the electric heater rather than relying on autosize for your use case. It sounds like these are imitating heaters that plug into walls, so choosing a fixed value for the unit heater makes the most sense.

Hope that helps a bit!