# Monitoring points

> Every heat network assurance monitoring point mapped to its six-level MQTT address, with units and minimum data frequency.

Every monitoring point that heat network technical assurance asks for, with the address it is published under in [HNQAP-MQTT v1](/protocol/). 106 entries, generated 2026-10-25. Download as [monitoring-points.json](/data/monitoring-points.json).

A full address is `{schema}/{network}/{element}/` followed by the device, vargroup and varkey shown. On a monitored element the device is named for the point it serves (`intake`, `offtake`, `boundary` and so on, see [protocol §2.2](/protocol/#22-elements-and-devices-on-monitored-networks)), so a receiver finds each point without a mapping step:

```
acme/riverside_court/ss1/intake/hmeter/kwh
```

Point codes and descriptions paraphrase the scheme drafts; the scheme documents remain the authority. Some of these names, including the `hmeter` and `meter` vargroups, are in use on live networks but not yet in the [vocabulary](/vocabulary/) export. They are being registered, and this table is their reference until then. Comments on any address are welcome as [issues](https://github.com/heatweb/HNQAP/issues/new?template=protocol-comment.yml).

## Energy Centre (EC)

**Live readings**

| Point | Monitoring point | Quantity | Address (device/vargroup/varkey) | Units | Minimum frequency |
|---|---|---|---|---|---|
| EC5 | Make-up Water meter | Accumulated Volume | `makeup/meter/m3` | m³ | 30 min |
| EC8 | Operating pressure measurement point | Static Pressure | `pressure/sensor/pSystem` | bar | 5 min |
| EC7 | Distribution differential pressure measurement point | Differential Pressure | `EC7/sensor/dpSupply` | kPa | 5 min |
| EC4 | Distribution pump set | Accumulated Energy | `pump/emeter/kwhElectric` | kWh | 30 min |
| EC3 | Energy Centre boundary | Accumulated Energy | `boundary/hmeter/kwh` | kWh | 5 min |
| EC3 | Energy Centre boundary | Accumulated Volume | `boundary/hmeter/m3` | m³ | 5 min |
| EC3 | Energy Centre boundary | Flow Temperature | `boundary/hmeter/tF` | °C | 5 min |
| EC3 | Energy Centre boundary | Instantaneous Flow Rate | `boundary/hmeter/m3h` | m³/h | 5 min |
| EC3 | Energy Centre boundary | Instantaneous Power | `boundary/hmeter/kw` | kW | 5 min |
| EC3 | Energy Centre boundary | Return Temperature | `boundary/hmeter/tR` | °C | 5 min |
| EC6 | Index differential pressure measurement point | Differential Pressure | `EC6/sensor/dpIndex` | kPa | 5 min |
| EC2 | Heat Source energy output | Accumulated Energy | `EC2/hmeter/kwh` | kWh | 5 min |
| EC2 | Heat Source energy output | Accumulated Volume | `EC2/hmeter/m3` | m³ | 5 min |
| EC2 | Heat Source energy output | Flow Temperature | `EC2/hmeter/tF` | °C | 5 min |
| EC2 | Heat Source energy output | Instantaneous Flow Rate | `EC2/hmeter/m3h` | m³/h | 5 min |
| EC2 | Heat Source energy output | Instantaneous Power | `EC2/hmeter/kw` | kW | 5 min |
| EC2 | Heat Source energy output | Return Temperature | `EC2/hmeter/tR` | °C | 5 min |
| EC1 | Heat source energy input | Accumulated Energy | `EC1/meter/kwh` | kWh | 30 min |
| EC1 | Heat source energy input | Accumulated Volume of Gas | `EC1/meter/m3Gas` | m³ | 30 min |

**Values entered once** (design, identity)

| Value | Address | Units |
|---|---|---|
| HNTAS element code — instance ID assigned at registration (e.g. 00005) | `system/elementCode` |  |
| Parent element — energy flows from here (e.g. cd1 / cd1) | `system/parentElement` |  |
| System Volume | `design/systemVolume` | litres |
| Maximum System Pressure | `design/maxPressure` | bar |
| Maximum Supply DP | `design/maxDPSupply` | kPa |
| Design Annual Pump Energy Use | `design/kwhAnnualPump` | kWh |
| Design flow temperature | `design/tF` | °C |
| Minimum Flow Temperature | `design/minFlowTemp` | °C |
| Minimum Index Differential Pressure | `design/minDPIndex` | kPa |
| Minimum Generation Efficiency | `design/efficiency` | % |
| DESNZ fuel type ID (carbon calculator Table 1: 17 mains gas, 25 natural gas, 28 electricity, 27 biomass, 15 hydrogen) | `design/fuelType` | ID |
| Declared boiler efficiency (fraction or %) - carbon fuel-input fallback when generation is unmetered | `design/boilerEfficiency` | fraction |
| Design heat fraction of the lead heat source | `design/heatFraction` | % |

**Derived by the platform**

| Value | Address | Units |
|---|---|---|
| Distribution efficiency (delivered / generated) | `kpi/distributionEfficiency` | % |
| Carbon content of delivered heat | `kpi/carbonContent` | kgCO2e/kWh |

## District Distribution (DD)

**Live readings**

| Point | Monitoring point | Quantity | Address (device/vargroup/varkey) | Units | Minimum frequency |
|---|---|---|---|---|---|
| DD3 | DP Measuring Point | Differential pressure at Index | `DD3/sensor/dpIndex` | kPa | 5 min |
| DD1 | Intake Boundary | Accumulated Energy | `intake/hmeter/kwh` | kWh | 30 min |
| DD1 | Intake Boundary | Accumulated Volume | `intake/hmeter/m3` | m³ | 30 min |
| DD1 | Intake Boundary | Flow Temperature | `intake/hmeter/tF` | °C | 30 min |
| DD1 | Intake Boundary | Return Temperature | `intake/hmeter/tR` | °C | 30 min |
| DD1 | Intake Boundary | Instantaneous Power | `intake/hmeter/kw` | kW | 30 min |
| DD1 | Intake Boundary | Instantaneous Flow Rate | `intake/hmeter/m3h` | m³/h | 30 min |

**Values entered once** (design, identity)

| Value | Address | Units |
|---|---|---|
| HNTAS element code — instance ID assigned at registration (e.g. 00005) | `system/elementCode` |  |
| Parent element — energy flows from here (e.g. cd1 / cd1) | `system/parentElement` |  |
| Minimum Index Differential Pressure | `design/minDPIndex` | kPa |
| Expected average flow temperature | `design/tF` | °C |
| Expected average return temperature | `design/tR` | °C |
| Design maximum bypass flowrate | `design/maxBypassFlow` | m³/h |
| Minimum required flow temperature | `design/minFlowTemp` | °C |
| Dwellings served (heat-loss W/dwelling basis) | `design/dwellings` |  |
| Non-domestic connected load (heat-loss W/kW basis) | `design/kwConnection` | kW |

**Derived by the platform**

| Value | Address | Units |
|---|---|---|
| Flow/return ΔT | `kpi/deltaT` | K |

## Substation (SS)

**Live readings**

| Point | Monitoring point | Quantity | Address (device/vargroup/varkey) | Units | Minimum frequency |
|---|---|---|---|---|---|
| SS6 | Defined differential pressure exceedance measurement point | Differential Pressure | `SS6/sensor/dpOff` | kPa | 5 min |
| SS5 | Defined index differential pressure measurement point | Differential Pressure | `SS5/sensor/dpIndex` | kPa | 5 min |
| SS7 | Defined operating pressure measurement point | Static Pressure | `pressure/sensor/pOff` | bar | 5 min |
| SS1 | Intake Boundary | Accumulated Energy | `intake/hmeter/kwh` | kWh | 5 min |
| SS1 | Intake Boundary | Accumulated Volume | `intake/hmeter/m3` | m³ | 5 min |
| SS1 | Intake Boundary | Flow Temperature | `intake/hmeter/tF` | °C | 5 min |
| SS1 | Intake Boundary | Instantaneous Flow Rate | `intake/hmeter/m3h` | m³/h | 5 min |
| SS1 | Intake Boundary | Instantaneous Power | `intake/hmeter/kw` | kW | 5 min |
| SS1 | Intake Boundary | Return Temperature | `intake/hmeter/tR` | °C | 5 min |
| SS3 | Network distribution pump | Accumulated Energy | `pump/emeter/kwhElectric` | kWh | 30 min |
| SS2 | Offtake Boundary | Accumulated Energy | `offtake/hmeter/kwhOff` | kWh | 5 min |
| SS2 | Offtake Boundary | Accumulated Volume | `offtake/hmeter/m3Off` | m³ | 5 min |
| SS2 | Offtake Boundary | Flow Temperature | `offtake/hmeter/tFOff` | °C | 5 min |
| SS2 | Offtake Boundary | Instantaneous Flow Rate | `offtake/hmeter/m3hOff` | m³/h | 5 min |
| SS2 | Offtake Boundary | Instantaneous Power | `offtake/hmeter/kwOff` | kW | 5 min |
| SS2 | Offtake Boundary | Return Temperature | `offtake/hmeter/tROff` | °C | 5 min |
| SS4 | Water meter | Accumulated Volume | `watermeter/meter/m3` | m³ | 30 min |

**Values entered once** (design, identity)

| Value | Address | Units |
|---|---|---|
| HNTAS element code — instance ID assigned at registration (e.g. 00005) | `system/elementCode` |  |
| Parent element — energy flows from here (e.g. cd1 / cd1) | `system/parentElement` |  |
| Maximum Supply DP | `design/maxDPOff` | kPa |
| Minimum Index Differential Pressure | `design/minDPIndex` | kPa |
| Maximum System Pressure | `design/maxPressure` | bar |
| Design Annual Pump Energy Use | `design/kwhAnnualPump` | kWh |
| Maximum PHE Approach Temperature | `design/maxApproachTemp` | °C |
| Minimum Output Temperature | `design/minFlowTempOff` | °C |
| Design flow temperature (secondary) | `design/tFOff` | °C |
| System Volume | `design/systemVolume` | litres |

## Communal Distribution (CD)

**Live readings**

| Point | Monitoring point | Quantity | Address (device/vargroup/varkey) | Units | Minimum frequency |
|---|---|---|---|---|---|
| CD3 | DP Measuring Point | Differential pressure at Index | `CD3/sensor/dpIndex` | kPa | 5 min |
| CD1 | Intake Boundary | Accumulated Energy | `intake/hmeter/kwh` | kWh | 30 min |
| CD1 | Intake Boundary | Accumulated Volume | `intake/hmeter/m3` | m³ | 30 min |
| CD1 | Intake Boundary | Flow Temperature | `intake/hmeter/tF` | °C | 30 min |
| CD1 | Intake Boundary | Instantaneous Flow Rate | `intake/hmeter/m3h` | m³/h | 30 min |
| CD1 | Intake Boundary | Instantaneous Power | `intake/hmeter/kw` | kW | 30 min |
| CD1 | Intake Boundary | Return Temperature | `intake/hmeter/tR` | °C | 30 min |

**Values entered once** (design, identity)

| Value | Address | Units |
|---|---|---|
| HNTAS element code — instance ID assigned at registration (e.g. 00005) | `system/elementCode` |  |
| Parent element — energy flows from here (e.g. cd1 / cd1) | `system/parentElement` |  |
| Minimum Index Differential Pressure | `design/minDPIndex` | kPa |
| Expected average flow temperature | `design/tF` | °C |
| Expected average return temperature | `design/tR` | °C |
| Dwellings served (heat-loss W/dwelling basis) | `design/dwellings` |  |
| Non-domestic connected load (heat-loss W/kW basis) | `design/kwConnection` | kW |
| Design maximum bypass flowrate | `design/maxBypassFlow` | m³/h |
| Minimum flow temperature | `design/minFlowTemp` | °C |

**Derived by the platform**

| Value | Address | Units |
|---|---|---|
| Accumulated Energy | `calculated/kwh` | kWh |
| Accumulated Volume | `calculated/m3` | m³ |

## Consumer Connection (CC)

**Live readings**

| Point | Monitoring point | Quantity | Address (device/vargroup/varkey) | Units | Minimum frequency |
|---|---|---|---|---|---|
| CC1 | Consumer Connection Boundary | Accumulated Energy | `boundary/hmeter/kwh` | kWh | 30 min |
| CC1 | Consumer Connection Boundary | Accumulated Volume | `boundary/hmeter/m3` | m³ | 30 min |
| CC1 | Consumer Connection Boundary | Flow Temperature | `boundary/hmeter/tF` | °C | 30 min |
| CC1 | Consumer Connection Boundary | Instantaneous Flow Rate | `boundary/hmeter/m3h` | m³/h | 30 min |
| CC1 | Consumer Connection Boundary | Instantaneous Power | `boundary/hmeter/kw` | kW | 30 min |
| CC1 | Consumer Connection Boundary | Return Temperature | `boundary/hmeter/tR` | °C | 30 min |

**Values entered once** (design, identity)

| Value | Address | Units |
|---|---|---|
| HNTAS element code — instance ID assigned at registration (e.g. 00005) | `system/elementCode` |  |
| Parent element — energy flows from here (e.g. cd1 / cd1) | `system/parentElement` |  |
| HNTAS metering point ID | `system/hntasMPID` |  |

**Derived by the platform**

| Value | Address | Units |
|---|---|---|
| Flow/return ΔT | `kpi/deltaT` | K |