HPBS Xeto Library

Xeto schema library implementing the High Performance Building Standard (HPBS) for Project Haystack.

About HPBS

The High Performance Building Standard (HPBS) is a comprehensive construction standard developed by the Utah Division of Facilities Construction and Management (DFCM). HPBS defines requirements for building automation systems, including point naming conventions, data collection intervals, and equipment modeling.

This Xeto library implements the HPBS conventions as defined in the HPBS Appendix F - Analytic Points and Tagging Standard, providing standardized point types, equipment templates, and system definitions for Haystack-compatible building automation.

Design Philosophy

This library follows a thin extension approach:

1. Extend, don't replace - All types inherit from standard Haystack types
2. Preserve interoperability - HPBS points remain queryable with standard Haystack queries
3. Add value, not complexity - Only include HPBS-specific conventions that provide real benefit
4. Composition over inheritance - Add HPBS defaults without deep hierarchies

What This Library Provides

History Collection Presets

Standardized history collection intervals for different point types:

Mixin	Mode	Interval	Use Case
HpbsHisCov	COV	24hr	Commands, setpoints, status points
HpbsHisSampled	Sampled	10min	Zone sensors, secondary equipment
HpbsHisSampledMajor	Sampled	5min	Major equipment sensors
HpbsHisConsumption	Consumption	10min	Submeters
HpbsHisConsumptionMajor	Consumption	5min	Main meters

Unit Preferences

HPBS uses imperial units:

Domain	Unit	Mixin
Temperature	°F	HpbsTempUnits
Air pressure	inH₂O	HpbsAirPressureUnits
Water pressure	psi	HpbsWaterPressureUnits
Air flow	cfm	HpbsAirFlowUnits
Water flow	gal/min	HpbsWaterFlowUnits
Humidity	%RH	HpbsHumidityUnits
CO2	ppm	HpbsCo2Units
Gas volume	ft³	HpbsGasVolumeUnits
Gas energy	therm	HpbsGasEnergyUnits

NavName Conventions

Consistent abbreviated display names for points:

Point Type	NavName Example
Zone Temperature	ZnTemp
Discharge Air Temp	DaTemp
Chilled Water Valve	ChwVlvCmd
Supply Fan Speed	SfSpd
Boiler Run Status	BlrRunSts

Library Structure

Layered Architecture

The library uses a two-layer architecture:

Layer	File Pattern	Purpose
Placeholder	ph.*.xeto	Generic base specs intended for upstream contribution to Project Haystack
HPBS Implementation	*.xeto	HPBS-specific specs with colors, navNames, and history settings

Core Files

File	Description
lib.xeto	Library metadata and dependencies
points.xeto	Base point types, color mixins, and history presets

Point Type Files

File	Contents
air.xeto	Air temperature, humidity, flow, pressure, CO2 points
water.xeto	Water temperature, flow, pressure, volume, energy (HW, CHW, CW)
fans.xeto	Fan run/status, speed, VFD points (supply, return, exhaust, relief)
valves.xeto	Valve position/command points (heating, cooling, bypass, isolation)
dampers.xeto	Damper position points (OA, RA, EA, mixed, economizer, zone)
pumps.xeto	Pump run/speed points (HW, CHW, CW, DHW, booster)
stages.xeto	Staging points (heating, cooling stages)
boiler.xeto	Boiler-specific staging and control points
chiller.xeto	Chiller-specific staging, load, and oil system points
compressor.xeto	Compressor staging and run points
cooling-tower.xeto	Cooling tower staging and control points
occupancy.xeto	Occupancy, schedule, override, lockout, alarm points
electrical.xeto	Electrical metering points (energy, power, demand)
naturalgas.xeto	Natural gas metering points (flow, volume, energy)
steam.xeto	Steam system points (flow, pressure, temperature, energy)
dhw.xeto	Domestic hot water points
alarms.xeto	Equipment and system alarm points
heatexchanger.xeto	Heat exchanger temperature points

Placeholder Files (for upstream contribution to ph xeto libraries)

File	Contents
ph.point_air.xeto	Generic air point placeholders
ph.point_water.xeto	Generic water point placeholders
ph.point_fan.xeto	Generic fan point placeholders
ph.point_valve.xeto	Generic valve point placeholders
ph.point_damper.xeto	Generic damper point placeholders
ph.point_pump.xeto	Generic pump point placeholders
ph.point_boiler.xeto	Generic boiler point placeholders
ph.point_chiller.xeto	Generic chiller point placeholders
ph.point_compressor.xeto	Generic compressor point placeholders
ph.point_cooling-tower.xeto	Generic cooling tower point place.olders
ph.point_stages.xeto	Generic staging point placeholders
ph.point_misc.xeto	Miscellaneous point placeholders
ph.point_co2.xeto	CO2 point placeholders
ph.point_weather.xeto	Weather point placeholders
ph.point_systems.xeto	Placeholder equipment specs
ph.equip.xeto	Placeholder equipment specs

Equipment and System Files

File	Description
equips.xeto	Equipment types with point profiles (AHU, VAV, boiler, chiller, etc.)
systems.xeto	Distribution system types (chilled water, hot water, steam, condenser water)

Point Type Coverage

Air Points (~80 types)

• Zone, discharge, mixed, return, outside, inlet air temperatures
• Zone, discharge, return, outside humidity
• Zone, discharge, return, outside, exhaust, mixed air flow
• Zone, discharge, building air pressure
• Zone, discharge, return CO2
• Weather (wet bulb, dew point, freeze stat)

Water Points (~50 types)

• Hot water (entering, leaving, supply, return, delta-T)
• Chilled water (entering, leaving, supply, return, delta-T)
• Condenser water (entering, leaving, supply, return)
• Domestic hot water (supply, return)
• Flow, pressure, differential pressure, volume, energy

Fan Points (~40 types)

• Supply, return, exhaust, relief, cooling tower fans
• Run command/status, speed sensor/command
• VFD frequency, fault, enable
• Power and energy

Valve Points (~35 types)

• Hot water, chilled water, condenser water valves
• Heating, cooling, preheat, reheat valves
• Bypass and isolation valves
• Steam and gas valves
• Domestic hot water valves

Damper Points (~30 types)

• Outside air, return air, exhaust, relief dampers
• Mixed air, economizer dampers
• Zone/VAV dampers with min/max setpoints
• Discharge, bypass dampers
• Fire/smoke dampers

Pump Points (~40 types)

• Hot water, chilled water, condenser water pumps
• Primary and secondary pumps
• Domestic hot water recirculation pumps
• Booster pumps
• Power, energy, VFD points

Staging Points (~40 types)

• Heating/cooling stages (electric, gas, DX)
• Compressor stages
• Boiler/chiller staging and control
• Cooling tower staging
• Lead/lag sequencing

Occupancy Points (~30 types)

• Zone occupancy sensor/command
• Operating mode points
• Schedule points (optimal start)
• Override and lockout points
• DCV points
• Alarm points

Metering Points (~25 types)

• Natural gas (flow, volume, energy, pressure)
• Electrical (energy, power, demand)
• Steam (flow, pressure, temperature, energy)
• Building and equipment submeters

Equipment Types (~40 types)

• Air handlers (AHU, RTU, MAU, DOAS)
• VAV terminals (standard, reheat, fan-powered)
• Boilers (hot water, steam, condensing)
• Chillers (air-cooled, water-cooled, centrifugal, screw)
• Cooling towers (open, closed)
• Fan coil units (2-pipe, 4-pipe)
• Computer room (CRAC, CRAH)
• Heat pumps, heat exchangers
• Meters (electric, gas, water, BTU, steam)

System Types

• Chilled water systems
• Hot water systems
• Steam systems
• Condenser water systems
• Domestic hot water systems

Equipment Point Profiles

Each equipment type defines a points: {} block specifying which point types typically apply to that equipment. This provides:

• Self-documenting templates - Equipment types show exactly which points are expected
• No duplication - References existing point types instead of creating equipment-specific variants
• Flexibility - All points are optional (?) - instances only include what they have

Slot Naming Convention

Slot names in points: {} blocks match the point type's navName abbreviation:

Slot Name	Point Type	NavName
daTemp	HpbsDischargeAirTempSensor	DaTemp
sfCmd	HpbsSupplyFanRunCmd	SfCmd
chwVlvCmd	HpbsChilledWaterValveCmd	ChwVlvCmd
znTemp	HpbsZoneAirTempSensor	ZnTemp

Equipment Point Counts

Equipment	Points	Key Categories
HpbsAhu	~30	Air temps, fans, dampers, valves, safety
HpbsVav	~10	Zone temp/flow, damper, occupancy
HpbsVavReheat	~13	VAV + reheat valve, discharge temp
HpbsBoiler	~14	HW temps, staging, gas, enable
HpbsChiller	~15	CHW/CW temps, staging, power
HpbsCoolingTower	~17	Fans, temps, staging, isolation
HpbsFcu	~11	Zone temp, fan, valves

How to use these libraries

• As a user

  • Install & enable the library (hpbs) in your Haxall project.
  • Declare equipment and points using the provided Hpbs types, extending abstract base types (such as HPBSAhu) for project-specific variants.

• As a contributor

  • Prefer extending or composing existing Hpbs traits/types instead of duplicating semantics.
  • Follow existing naming and history conventions within the hpbs libraries.

Contributing

We welcome contributions! Please see our Contributing Guide for details on:

• Development setup and guidelines
• Code style and naming conventions
• Pull request process
• Types of contributions we accept

Example: AHU Point Profile

HpbsAhu: Ahu {
  points: {
    // Air temperatures
    daTemp: HpbsDischargeAirTempSensor?
    daTempSp: HpbsDischargeAirTempSp?
    maTemp: HpbsMixedAirTempSensor?
    raTemp: HpbsReturnAirTempSensor?
    oaTemp: HpbsOutsideAirTempSensor?

    // Supply fan
    sfCmd: HpbsSupplyFanRunCmd?
    sfSts: HpbsSupplyFanRunSensor?
    sfSpd: HpbsSupplyFanSpeedSensor?

    // Dampers
    oaDmprCmd: HpbsOutsideAirDamperCmd?
    raDmprCmd: HpbsReturnAirDamperCmd?

    // Valves
    chwVlvCmd: HpbsChilledWaterValveCmd?
    hwVlvCmd: HpbsHeatingValveCmd?
  }
}

Using Pre-composed Types

// Use HPBS types directly - all Haystack queries still work
myZoneTemp: HpbsZoneAirTempSensor {
  equipRef: @my-vav
}

myChwValve: HpbsChilledWaterValveCmd {
  equipRef: @my-ahu
}

Using Equipment Templates

Equipment types define expected points - just instantiate what you have:

// Create an AHU with its points
myAhu: HpbsAhu {
  dis: "AHU-1"
  siteRef: @my-site
}

// Points reference the equipment - the equipment's points: {} block
// documents which point types are expected
myDaTemp: HpbsDischargeAirTempSensor {
  equipRef: @myAhu
}

mySupplyFan: HpbsSupplyFanRunCmd {
  equipRef: @myAhu
}

Installation

Add to your Haxall project's lib dependencies:

depends: {
  { lib: "hpbs", versions: "1.0.x" }
}

Interoperability

All HPBS types remain fully Haystack-compatible:

// These queries work with HPBS points
read(sensor and air and temp)     // Finds HpbsZoneAirTempSensor
read(boiler)                       // Finds HpbsBoiler
read(chiller)                      // Finds HpbsChiller
read(his and sampled)              // Finds sampled history points
read(vav and hotWaterReheat)       // Finds HpbsVavReheat

Target Platform

• Haxall: 4.x
• Haystack: 5 (ph 5.0.x)

References

• High Performance Building Standard (HPBS)
• HPBS Appendix F - Analytic Points and Tagging Standard
• Project Haystack - Industry standard for building data semantics
• Haxall Framework - IoT framework that runs Xeto libraries
• Xeto Language - Official Xeto specification and standard libraries

License

Academic Free License version 3.0