Radiant Panel Sensor/Setpoint Questions

[gtfierro]

Context: we are adding attributes to Brick point classes to support better queries and to ensure greater consistency in how points are modeled. See the following for more context:

• https://github.com/BrickSchema/Brick2-specification-drafting/tree/main/point-attributes
• Missing hasQuantity and hasSubstance properties for some Point classes #713
• Consistency of hasQuantity/hasSubstance on Point subclasses and Point instances #696

The relevant Brick point classes are:

Class	Type	Notes
brick:Radiant_Panel_Temperature_Sensor	Sensor	Generic radiant panel temperature
brick:Radiant_Panel_Temperature_Setpoint	Setpoint	Generic radiant panel temperature
brick:Core_Temperature_Sensor	Sensor	Temperature at heat source/sink level
brick:Core_Temperature_Setpoint	Setpoint	Temperature at heat source/sink level
brick:Embedded_Temperature_Sensor	Sensor	Internal temperature of radiant layer
brick:Embedded_Temperature_Setpoint	Setpoint	Internal material (e.g. concrete slab)
brick:Inside_Face_Surface_Temperature_Sensor	Sensor	Inside surface relative to the space
brick:Inside_Face_Surface_Temperature_Setpoint	Setpoint	Inside face surface temperature
brick:Outside_Face_Surface_Temperature_Sensor	Sensor	Outside surface relative to the space
brick:Outside_Face_Surface_Temperature_Setpoint	Setpoint	Outside face surface temperature

Sensor position on radiant panels/slabs:

We have points that measure temperature at specific positions within or on a radiant panel or slab (e.g., a radiant floor or ceiling). We're not sure how to model the sensor's position as a Brick attribute.

1. What positions are standard? We've seen references to:

   • core
   • embedded
   • inside face surface
   • outside face surface
   • are core and embedded the same thing? What's the full range of values?

2. Is sensor position a location (like a brick:Location), or is it something else — a measurement modifier, a structural annotation, or something specific to radiant systems?

Substance for radiant slab temperature sensors:

3. What is the substance being measured for a radiant slab core temperature sensor? Is the substance "concrete"? Or is substance not the right attribute here at all?

These came up as we were working through radiant panel point types. Happy to provide more context if helpful!

[carlosduarteroa]

It is great that there is an effort to standardize points for radiant systems. I proposed these initial Brick concepts so I can clarify further my initial thinking and intent.

1. There is no standard sensor position, but the proposed references are intended to account for the recommendations in practice, depending on the purpose of the measurement (control, monitoring, or research).

   • Surface: This placement would be at or near the surface of the slab. The purpose of this sensor placement so that the measurements represent what occupants sense. It is also the most common for control. The distinction between inside and outside is to give additional context, which surface is being measured relative to the zone. Illustrated in the figure below.
   • Core: This placement would be near the center of the slab, often close to the tube elevation. The purpose of this sensor placement is to better understand the slab's thermal storage state and use it for advanced TABS control.
   • Embedded: This reference was to consider where the data modeler didn't really know where the sensor was. They just know it is embedded within the slab. This can be used in conjunction with a 'distance property' to cover situations where the sensor location is known but is not a surface or core sensor placement.
   • The sensor placement can be anywhere within the slab since it is not a standardized position for radiant systems. The above references would cover the majority of the recommended practice or unknown placement.

Referenced Zone

                              Inside Surface
				      _ _ _ _ _ _ _ _ _
Inside Surf sensor-> │
				     │
				     │
   Core sensor     ->│ Water Tubes (~mid slab)
				     │
				     │
Outside Surf sensor->│_ _ _ _ _ _ _ _ _
				
                             Outside Surface

2. I think the above references can be represented as a location. That way, it can be used for any generic temperature sensor and not tied to radiant systems specifically.
3. Yes, for a high thermal mass radiant system, the substance usually measured would be concrete or concrete-like material. However, when referencing the surface temperature, for a radiant metal panel, the substance being measured is the metal of the panel.