EnergyPlus cannot model non-homogeneous layers such as the hollow core slab. That layer should be modeled with the correct mass (thickness + density) and an average conductance.
The embedded pipes are not something I have modeled, but I believe that there are several radiant floor objects that will work for you. Look into object names such as ZoneHVAC:LowTemperatureRadiant:ConstantFlow.
James V Dirkes II, PE, BEMP, LEED AP
Energy Analysis, Commissioning & Training Services
1631 Acacia Drive, Grand Rapids, MI 49504 USA
616 450 8653
From: EnergyPlus_Support@xxxxxxxxxxxxxxx [mailto:EnergyPlus_Support@xxxxxxxxxxxxxxx] On Behalf Of Athinodoros Tzoulis
Sent: Sunday, November 03, 2013 12:18 PM
Subject: [EnergyPlus_Support] hollow core slabs [1 Attachment]
1) I would like to model a hollow core slab in a room and above it a concrete layer with embedded water pipes for concrete core activation.
Is there a possibility to do it in EnergyPlus?
I have seen a possibility to do it in but as a ventilated slab. However I don't want ventilation in the room.
2) I have modelled a room with a heated floor inside a solid concrete slab.
Is it possible to separate the system in 2 or more loops within the slab. So, having embedded tubes in the slab in the whole slab but having more than 2 water inlet and outlet nodes (as it is in reality)? (see pic)
Is there a possibility to model this system with virtual partitions?