Current tag set has a primaryLoop and a secondaryLoop, which seems very specific. Would it be possible to get a generic loop, and then we can tag it as necessary? We have projects where there are multiple tertiary loops, and we don't have a way to describe them with the current tag set.

We already have tags to describe the types of loops typically present in facilities - chilled / condenser / water, and could use these to describe the generic loop. You could also use a refrig tag to describe a loop between a compressor and coil, as those typically have sensing and control equipment associated with them.

I think it makes a lot of sense to leave the tags as abstract as possible and let the users decide how to use them. In this sense, I would get rid of the primaryLoop, secondaryLoop, and consider getting rid of the chillerPlant / boilerPlant tags, and just associate the equipment with a loop equip, which more accurately reflects how systems are laid out.

I like the idea of having a loop tag whose value could identify the loop. Because often there are multiple loops of the same type; such as a secondary chilled water loop that only feeds the air handlers and another which only feeds the fan coils; each of which could have its own pumps and sensors.

However I think the primaryLoop and secondaryLoop tags are essential to defining the loops relationship to the primary plant equipment. And in the situation that any additional loop comes off a secondary loop, it is still really a secondary loop. The primary/secondary loop tags really tells you if a change in loop flow will change the flow through the boiler/chiller, which can drastically alter the ways that loop could be controlled.

I agree with you Leroy on the importance of distinguishing between a primary and secondary loop, or whatever other loops might be present in the system.

What I think I meant to say is that a loop point should be an abstract - similar to a pump. We can then describe the loop in the same way we do a pump - by applying tags to it. I don't think it makes sense to have an equip type of primaryPump and secondaryPump in the same way I don't think it makes sense to have a specific primaryLoop and secondaryLoop. I think a better approach is to make a loop, and then apply the primary / secondary / whatever tags to it.

So for a primary chilled water loop, you could apply the loop tag to the equip, and then apply chilled and water to it, and then marker it with primary, secondary, whatever. The way we're approaching this specifically is to leave them generic, and then let the other components that reference the loop determine it's function.

Todd, After Haystack Connect, we started a working group on Chiller Plants. One item that came up is the concept of looking at the primaryLoop and secondaryLoop as pieces of equipment similar to an AHU.

We have not gotten too far into this yet, but I think you are on the same wavelength as some of the other folks. If you send an email to [email protected] I will forward to you some of the correspondence to date.

I like the tertiaryLoop tag. Maybe tertiaryLoop:1, tertiaryLoop:2 etc might work

My vote goes to a simple loop tag.

This would fit a lot of applications

1. : discharge air temperature loop, etc.

equipRef can then be used to refer to the device being controlled by the loop if needed.

In regard to primaryLoop and secondaryLoop, I think we would be better served by splitting the tags. For me, primary, secondary, tertiary are tags. My 2 cents.

primary loop is as good as primaryLoop with the benefit to be able to use primary elsewhere.

Best e-mail to add me with would be [email protected].

I'm with Christian on this one - why do we have to make the loop specific, especially when it can be described using existing tags? If we move toward making equip abstract, and use tags to describe that equipment, that frees us up to make things truly self-describing and doesn't limit what we can do with the tags.

I like the idea of a loop being its own entity which could be referenced by equipment attached to it and described by tags. However I don't think it should get an actual equip tag, as I think that would make for confusing nav trees and such.

I agree that primary could potentially be as good as primaryLoop and multi-use tags can be beneficial. But the tags still need to have a pretty definitive definition to be of use. Case in point Christian's example above, I would assume is referring to a control loop? That would considerably change the definition of how I would think a loop tag would be used.

I'm also happy to help if you are looking to take the discussion offline and I can be of any help [email protected]

You are absolutely right, I've always thought about the loop as a control loop ! Never as the physical piping consisting of a loop...

I would think that if refering to a physical loop, wouldn't it be better to have some kind of equipRef that would be a "physical loop" vs a tag which is applied to an information of some sort ?

Leroy : If we currently have primaryLoop and secondaryLoop as equip, what would be the difference in making just a loop and describing it via tags? A loop is just as much a piece of equipment in a facility as an ahu, chiller, etc. A loop can have sensors and control equipment installed in it, and can be referenced by other equip.

How would this make for confusing nav trees? Wouldn't it make it cleaner, especially in cases where you have multiple loops in a facility?

I can see the potential confusion in a plain loop equip when it comes to control vs. physical, I'm just curious as to if we would ever see the need to tag a control loop. Would we have the need to identify a control loop? If we get to that level, would we be identifying programs, alarms, etc? As long as we're clear on the definition of the loop equip, having multiple equips with loop in it doesn't seem to be an issue. See : chill, chilled. Same concept.

The references to loop in Topic 341 reminded me of this discussion. If we look at loop as the piping equivalent of an electrical circuit, that should give us the structure and flexibility for analyzing piping systems with our existing tags.

• loop - An equip which models a piping system (or section of piping) for liquids and gases that may be operating under pressure or vacuum.