Table of Contents

Intro — Introduction
    Introduction
    Systems and Equipment
    Appendix
TagModel — Tagging meta-model
    Metamodel
    Entities
    Tags
    Example
Structure — Core entities and structure
    Overview
    Containment
    Dis
    Site

"AREA: square footage or square meters of the facility. This enables site normalization by area".

I believe the above definition is out of context with the other tag definitions. It has been my experience that when forming a site string of tags that "AREA" is used as the building name (or portion thereof for larger facilities) followed by a "system" tag "AHU1" then followed by the point description and value eg (SAT) 15 deg C. When combined <area><system><point> gives the following (Tower A, AHU1, SAT, 15 deg C )

I believe there is a place for "square footage or square meters" as an extra associated parameter of the site/area tag. However it is just as important to know the space details served by each air handler as it is for the overall building measured space.

When acronyms are used they must be easily expanded to full language values as with AHU1 - Air Handling Unit # 1 or SAT - Supply Air Temperature.

To name every sensor forever piece of equipment for a large building will result in possibly thousands of points and or tags.

Good points. There are always trade-offs in picking which names to use. One thing to consider is ISA 95 which uses a 7 level hierarchy of:

• enterprise
• site
• area
• process cell
• work unit
• equipment module
• control module

But one thing we tried hard to do in haystack is avoid the complexity of fixed hierarchies. In a large complex facility there are many different groups/hierarchy of equips, areas/zones, systems, points, etc. But it is difficult to standardize and force any single hierarchy that works well across a broad range of use cases. So we have designed the tagging model to allow multiple hierarchies to be defined which happily coexist with hierarchies we might standardize. The tagging model is multi-dimensional by its nature.

So that would lead me to two questions:

1. should we reserve the tag area to mean an area of a site versus the square footage/meters
2. could we achieve suitable agreement that something like area should be standardized and what would it mean?

My thoughts on question 1 are this: I think zone works well as an alternative to the term area for what you describe. And on the other hand, I can't think of a suitable term to use other than area to describe what we currently use that term for (square footage/meters). So I'm thinking we keep area as is, and use the term zone for future modeling of areas within a site/building. But open to hear other ideas for terminology.

I am skeptical that we are ready to answer question 2 (but think as we get further into the model it will come).

I see that we are viewing this matter from opposite perspectives. I note in the definition of site you are limiting the definition to one postal address. It is often difficult to identify one structure with a single address. It is more often that structures have multiple address and various configurations which would challenge many to identify the predominant address.There are numerous examples such as former twin towers of New York city, and university campuses. I do not wish to belabour this point, however if it is decided to use square footage then how exactly would the value be used where the total structure might use multiple air handler to serve various parts of the same building. I would suggest that the value of "area" would be quickly lost as it would not represent anything specific. For analytical purposes it would not lead to usable results as is being suggested.

I would suggest that further thought be given to this matter. Is there a definition for; process cell, work unit, equipment module and control module.

Are these ISA terms? If so, I do not see how they apply to Commercial buildings. I have been disappointed with ISA over my career of 30 plus years that ISA did not seem to be concerned about the commercial controls industry. Both ASHRAE and the commercial controls industry during that period developed standards and conventions for their industry without participation from ISA. I do not understand why the ISA format is first choice just now.

Please forgive my rant and look forward to working with you on this project. There is a lot to be achieved if agreement can be reached.

Winston

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Are these ISA terms? If so, I do not see how they apply to Commercial buildings.

My point wasn't to necessarily say anything about ISA 95, other than they defined a rigid hierarchy. I loosely took the term "site" from them for our basic model. Just a reference point, nothing I particularly like about that spec (anything with rigid schema or hierarchies is unlikely to work well in the real world).

It is more often that structures have multiple address and various configurations which would challenge many to identify the predominant address.There are numerous examples such as former twin towers of New York city, and university campuses

No model will perfectly address every building, but I think the concept of a facility with its own unique street address is a good rule of thumb that is easy to apply as the basics of what a "site" means. We can come up with lots of complex cases like campus environments where the fit isn't perfect, but I think you will agree the model is easily applied to 95%+ of the buildings out there.

Campus and portfolio analysis is really just another way to group/analyze things. I can't stress this enough: site/equip/point is just one very basic way to organize things. It is not the only organization - Haystack's tag model assumes that they might be other ways to organize things (either standardized or done a per project basis). All we are trying to do with site/equip/point is define the most basic level of organization that is easily standardized.

I think the beauty of this tag-based system is its flexibility in handling hierarchies of all shapes and sizes. At a former employer, we were trying to develop a rigid hierarchy that could handle all business types from the Enterprise down to a t-stat on the wall and it was just about impossible to do without developing an incredibly complex model.

Zone vs. Area

In my opinion, the term Zone does a much better job of representing a sub-section of a building (or site). The term Area is more generic and should be used as a parameter to represent the square feet/square meters associated with an object (building, zone, etc.). In this way, the term Area could also be used for the building envelope (walls and roofs) when calculating R-values and $/sq ft cost.

Brian, I sincerely regret my rant yesterday. I later realized that the "area" tag was a sub-tag to "site" as opposed to my earlier thinking that it was at an equal to "site". Having a better understanding of the present structure gives me a clearer picture for this effort.

In response to Andrew, the term "zone",I would suggest is better used to refer to a space (on a floor) or a facade of a building served by some common system such as a single VAV device, or perimeter heating/cooling system. The question then becomes;is "zone" a tag for a "system' or the structure? Once decided then the "tag" area would be appropriate to other stated aspects of a building structure.

Winston