Has anyone been able to handle heating load with a combination of Water-cooled VRF + Boiler?
My project has water-cooled VRF which is connected to cooling tower and boiler. I created the HVAC system with HVACTemplates (Zone:VRF, System:VRF, Plant:Tower, Plant:Boiler and Plant:MixedWaterLoop) in EnergyPlus 9-4-0.
The calculation completes, and cooling in summer works fine, but there is no heating in winter even though there are a very large heating load. No electricity and natural gas are used. Almost all the heating periods are counted as unmet hours.
When I change Condenser Type in HVACTemplate:system:VRF from WaterCooled to AirCooled, VRF handles heating load well. So, I think there is something wrong with MixedWaterLoop, but I don't know what it is. Operation Scheme Type in HVACTemplete:Plant:MixedWaterLoop is Default. I tried various Temperature Design Setpoint settings, but they didn't work. MixedWater is properly selected as Templete Plant Loop Type in HVACTemplete:Plant:Boiler.
I also tried to created the WSHP system with HVACTemplete:Zone:WaterToAirHeatPump instead of VRF, but I faced exactly the same problem with heating in winter.
I'd really appreciate it if someone could tell me why it doesn't go well.
