#202 Haystack 2.0.5 Update

Brian Frank Wed 13 Aug 2014

I excited to announce the latest update to Project Haystack. I've updated the official documentation with the proposals we have reached final agreement on.

New Meter Model

The proposal from 193 has been incorporated into the docs. This is a breaking change to how meters and their points are tagged.

Meters are now modeled as composable individual tags:

domestic water meter 
chilled water meter
condenser water meter
hot water meter
makeup water meter
blowdown water meter
condensate water meter
steam meter
elec meter
gas meter

The tags used on the meter points have been changed as follows:

kw -> power
kwh -> energy
flowRate -> flow  // consistent w/ AHU air flow
flowConsumption -> volume

The /doc/Energy chapter has been significantly rewritten to reflect these changes. In addition a slew of new tags has been added: domestic, hot, makeup, blowdown, condensate, power, energy, volume.

VFDs

The proposal from 193 for VFDs has been added. The new /doc/VFDs chapter covers the new model. This standardizes the the key points of VFDs:

There is also new sections for how to model pump and fan.

Chiller Enhancements

The proposal from 193 also adds additional point definitions for chiller. Mostly these are taken from the VFD and energy discussion. But there is also a new load tag for chiller load points.

JSON

Per the proposed changes in topic 50 there are two tweaks to the JSON encoding:

  • URIs are encoded as string literals with backticks "`uri`"
  • Numbers with a unit encode their unit as a separate field named "{tag}.unit"

Point Min/Max

Per topic 181 we've standardized the minVal and maxVal tags on point.

French Localization

There is new "fr.props" file available from downloads with the French translations for all the tags (from last update). This file was provided by Christian Tremblay.

File Downloads

The Downloads tab has been reworked a bit to include misc files to share with the community. We've posted the ai, eps, and png versions for the logos.

Denis OConnor Mon 18 Aug 2014

Did we consciously leave out the "feed water meter" tags recommendation from discussion #177?

Brian Frank Mon 18 Aug 2014

Did we consciously leave out the "feed water meter" tags recommendation

In a way yes. We don't have the boiler plant tags flushed out and that one wasn't really used by chillers/cooling towers. Nor was it clear to anybody who I talked to what exactly it means and how is it is different than makeup water.

If you can put together a concise definition and explanation on it, its easy to add for next rev

Denis OConnor Thu 21 Aug 2014

Good question.

The "makeup water" is added to the steam plant to account for condensate that is not returned to the plant.

The "feed water" is pumped directly into the boiler to replace the "blowdown water" and steam that leaves the boiler.

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