LowTemperatureRadiant:VariableFlow does not call up any Cooling Load when using Radiant Surface Type Floors

Edit: Label: Bug - Normal
When using the "LowTemperatureRadiant:VariableFlow" in OpenStudio for heating and cooling purposes there is no Cooling Load called up when the "Radiant Surface Type" is set to Floors. Changeing it to "Ceilings" makes the system work more or less like its supposed to (i think).

I have created the necessary internal source construction, using four layers and placing the pipes between the first and second layer. Tube Spacing set to 0.15m and all other Fields set to the number 1. It is then set as the material for Internal Surface Construction: Floors as well as Ground Contact Surface Construction. When running the simulation all other calculations seem to work out fine, loads and autosizing works the same. But no Cooling Load is called up by any of the radiant systems. Unlike Heating which gets called up in both cases. I use district heating and cooling, heating and cooling use a schedule to work during different month of the year.

I tested it with the exact same file and only changed this one setting (radiant surface type) and the results are as follows in the Screenshots

Pictures for Reference
Radiant Surface Type set to Ceiling

Radiant Surface Type set to Floor

Current Behavior

Simulation does not call up any cooling or heating loads at all. All affected rooms stay unconditioned by thes Radiant System

Expected Behavior

Simulation should call up at least similiar cooling or heating regardless of the Radiant Surface Type beeing Floors or Heating, not Zero.

Possible Solution

System works using Radiant Surface Type Ceiling.

Environment

I dont believe this to be an issue that is caused by the environment, but some basic info:

• Platform Windows 11
• Version of OpenStudio 1.9.0+d1f890902a
• Compiler: Ninja
• SO SDK (core) Version 3.9.0

I Have attatched my model for testing purposes. Thanks for all the work you guys put into OS!
Fabian

OS_SZ8_V4_noLoad_floor - Kopie.zip

load "OS_SZ8_V4_noLoad_floor.zip" -->

Start by running the attached model and compare simulations with LowTemperatureRadiant:VariableFlow set to Floors and Ceilings. Trace how the Radiant Surface Type is handled and verify whether cooling and heating loads are reported for affected rooms. Done means the floor configuration produces conditioning loads comparable to the ceiling configuration.