Re-investigate fire-related systems

[gtfierro]

There is some ambiguity in our classes around fire control systems. According to https://www.nfpa.org/News-and-Research/Publications-and-media/Blogs-Landing-Page/NFPA-Today/Blog-Posts/2021/03/03/A-Guide-to-Fire-Alarm-Basics we may want to have 3 broad types of equipment: fire control panel, fire alarm initiation systems, and fire alarm notification systems.

[ektrah]

Proposal:

• Fire Safety Equipment
  • Alarm Device
    • Audible Alarm Device (AAD)
    • Visual Alarm Device (VAD)
  • Fire Alarm Control Panel
  • Fire Detector
    • Carbon Monoxide Fire Detector
    • Flame Detector
    • Heat Detector
      • Line-Type Heat Detector
      • Point-Type Heat Detector
    • Smoke Detector
      • Aspirating Smoke Detector
      • Line-Type Smoke Detector
      • Point-Type Smoke Detector
  • Manual Alarm Initiating Device
    • Manual Call Point (MCP)
    • Pull Station

Details (click to expand)

| Proposal | EN 54-1 | [ISO 7240-1][1] | Brick 1.3 | |:--------------------------------------|:------------------------------------------|:--------------------------------------|:--------------------------------------------------------------| | Alarm Device | fire alarm device | fire alarm signalling device | `brick:Fire_Alarm` | | Aspirating Smoke Detector | aspirating smoke detector | aspirating smoke detector | | | Audible Alarm Device (AAD) | fire alarm sounder | audible alarm device (AAD) | | | Carbon Monoxide Fire Detector | carbon monoxide fire detector | carbon monoxide gas fire detector | | | Fire Alarm Control Panel | | | `brick:Fire_Control_Panel` / `brick:Fire_Alarm_Control_Panel` | | Fire Detector | fire detector | fire detector | | | Flame Detector | flame detector | flame detector | | | Heat Detector | heat detector | heat detector | `brick:Heat_Detector` | | Line-Type Heat Detector | linear heat detector | line-type heat detector | | | Line-Type Smoke Detector | line smoke detector using an optical beam | line-type smoke detector | | | Manual Call Point (MCP) | manual call point | manual call point | `brick:Fire_Alarm_Manual_Call_Point` | | Manual Alarm Initiating Device | | | `brick:Manual_Fire_Alarm_Activation_Equipment` | | Point-Type Heat Detector | heat detector ∩ point detector | heat detector ∩ point detector | | | Point-Type Smoke Detector | smoke detector ∩ point detector | smoke detector ∩ point detector | | | Pull Station | | | `brick:Fire_Alarm_Pull_Station` | | Smoke Detector | smoke detector | smoke detector | `brick:Smoke_Detector` | | Visual Alarm Device (VAD) | visual alarm device | visual alarm device (VAD) | | [1]: https://www.iso.org/obp/ui/en/#!iso:std:55316:en

[jbkoh]

Would like to add suppressing systems like extinguishers and sprinklers.

[jbkoh]

Also wonder if detectors could be an alarm at the same time in many cases (like home fire alarms)

[gtfierro]

Also wonder if detectors could be an alarm at the same time in many cases (like home fire alarms)

We can probably create an Alarm Point that we associate with the detectors to draw a distinction between the device and the signal

Or are you asking if it is both the "detector" and the "sound emitter"?

[jbkoh]

Or are you asking if it is both the "detector" and the "sound emitter"?

Yes. Those detectors emit sound as well, so either we have to adjust the hierarchy or let users instantiate both at the same time. I 'guess' it's common to have both functions.

[gtfierro]

According to the conversation I'm having on the REC gitter, future versions of DTDL (v3 in particular) will support up to 1024-way multiple inheritance. Azure Digital Twins v3 is still in preview I guess, so we don't know if REC will migrate to DTDLv3 yet. If they do, it will probably be after ADTv3 moves out of preview

[ektrah]

Or are you asking if it is both the "detector" and the "sound emitter"?

Yes. Those detectors emit sound as well, so either we have to adjust the hierarchy or let users instantiate both at the same time. I 'guess' it's common to have both functions.

Yes, I think it's quite common to have devices that combine multiple aspects (e.g., a point detector that detects both heat and smoke).

A sound-emitting fire detector, I think, I would model as a combination of a Fire_Detector and an Audible_Alarm_Device.

According to the conversation I'm having on the REC gitter, future versions of DTDL (v3 in particular) will support up to 1024-way multiple inheritance. Azure Digital Twins v3 is still in preview I guess, so we don't know if REC will migrate to DTDLv3 yet. If they do, it will probably be after ADTv3 moves out of preview

Great, then perhaps we can avoid the combinatorial explosion by using multiple inheritance here.

What would be the most pythonic brickish bricky way of doing this, e.g., for the Fire_Detector? Should there be one subclass for each item along each dimension?

• flame detectors, smoke detectors, heat detectors, carbon monoxide detectors;
• point detectors, line type detectors, multipoint detectors, aspirating detectors;
• resettable detectors, non-resettable detectors;
• detachable detectors, non detachable detectors.

[ektrah]

Relevant past discussion: https://github.com/BrickSchema/Brick/pull/336

[ektrah]

@gtfierro @jbkoh @epaulson I would like to ask for quick feedback as to whether the proposed terms in https://github.com/BrickSchema/Brick/issues/556#issuecomment-1708900836 are OK. If so, I would prepare a pull request so that the new equipment types can become part of Brick 1.4.

[jbkoh]

Though I like the hierarchy, I'm not sure if we have an agreement on the audible fire detector issue. Is the solution to have "Fire_Detector_with_Audible_Alarm"?

[jbkoh]

Btw, I'm looking to define Smoke Zones and Fire Zones too: https://ltc.health.mo.gov/archives/15059#:~:text=The%20fire%20alarm%20zones%20are,full%20evacuation%20of%20the%20building. Maybe this should go to REC though.

Smoke damper and fire dampers too.

[connorjcantrell]

@ektrah @jbkoh I suggest changing the term "Carbon Monoxide Fire Detector" to simply "Carbon Monoxide Detector." These devices primarily serve to identify the presence of CO gas originating from malfunctioning boilers, water heaters, leaking exhaust vents, or vehicles in enclosed parking areas. While they are associated with combustible sources, their primary function is not directly connected to fire detection or fire safety.

[ektrah]

As I understand it, on the one hand there are detectors that have the purpose of detecting fire and of which there are a number of variants that differ in the detection method (e.g., based on the presence of smoke, heat, flames, carbon monoxide). And on the other hand, there are detectors whose purpose is to detect the presence of gases. I'm not sure if carbon monoxide fire detectors and carbon monoxide detectors are interchangeable enough that we should combine them, even though they probably work internally very similarly. What do you think about having both?

[jbkoh]

Hi @ektrah yeah, we can have both and let the fire one be a subclass of the other one. However, if we distinguish "alarm device" from "detectors", sole detectors are equivalent to just "sensor equipment", and in that case having a separate class of "CO Detector" might be not super necessary.

So, I have to ask the question that I raised again; are "detectors" dedicated to just sensing something alone if we have Audible_Alarm_Device separately? In that case, what are the distinguishable features for detectors compared to Sensor Equipment's?

With regards, Jason Koh

On Thu, Feb 22, 2024 at 4:05 PM ektrah @.***> wrote:

As I understand it, on the one hand there are detectors that have the purpose of detecting fire and of which there are a number of variants that differ in the detection method (e.g., based on the presence of smoke, heat, flames, carbon monoxide). And on the other hand, there are detectors whose purpose is to detect the presence of gases. I'm not sure if carbon monoxide fire detectors and carbon monoxide detectors are interchangeable enough that we should combine them, even though they probably work internally very similarly. What do you think about having both?

— Reply to this email directly, view it on GitHub https://github.com/BrickSchema/Brick/issues/556#issuecomment-1960539217, or unsubscribe https://github.com/notifications/unsubscribe-auth/AAL76E6GSXUQC2WNMYTASPDYU7MMFAVCNFSM6AAAAAA4KUIKCOVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMYTSNRQGUZTSMRRG4 . You are receiving this because you were mentioned.Message ID: @.***>

[ektrah]

Here is how I understand it:

• A sensor¹ is a device that measures a physical quantity (such as temperature, humidity, flowrate, etc.). It can be installed in an air duct or water pipe or be part of a more complex device.
• A home weather station is a box that has the purpose of measuring the temperature and humidity in a room and has points that reflect these measurements. Internally, a home weather station might have a number of sensors¹ that perform the actual measurements, but these parts are usually not explicitly modeled as we are more interest in the points of the box.
• A water meter is a box that has the purpose of metering the volume of water consumed since some starting point and has a point that reflects these meterings. Internally, a water meter might have a sensor¹ that measures the flowrate of water, but this part is usually not modeled and there is no point that reflects these flowrate measurements.
• A fire detector is a box that has the purpose of detecting the presence of a fire and has a point that reflects these detections. Internally, a fire detector might have a sensor¹ that measures the concentration of carbon monoxide in the air surrounding the box, but this part is usually not modeled and there is no point that reflects these concentration measurements. However, we are often interested in the detection method used.
• A carbon monoxide fire detector therefore is a box that has the purpose of detecting the presence of fire using the measurement of carbon monoxide concentration as its detection method. It has a point that reflects these detections, but no point that reflects the concentration measurements.
• A carbon monoxide detector, on the other hand, is a box that has the purpose of detecting the (abnormal) presence of carbon monoxide and has a point that reflects these detections. Internally, a carbon monoxide detector might have a sensor¹ that measures the concentration of carbon monoxide in the air surrounding the box, but this part is usually not explicitly modeled as we are more interest in the point of the box.
• The different kinds of fire detectors and manual alarm initiating devices in general have the purpose of signaling a fire to a fire alarm control panel. The fire alarm control panel has the purpose of deciding how to react (sound an alarm, call the fire brigade, close fire dampers, ...) and sending commands to devices accordingly.
• An audible alarm device is a box that has the purpose of making noise to alert the occupants of a fire and that has a point for receiving commands.

The open question from my point of view is how to model a box that combines a fire detector and an audible alarm device.

(¹ in the sense of s223:Sensor, not brick:Sensor or brick:Sensor_Equipment)