The ZENNER zelsius C5-ISF is an economical single-jet heat meter for measuring heating and cooling energy in homes and small commercial buildings. A brass body, compact design and a choice of M-Bus, Wireless M-Bus or LoRaWAN communication give it broad application flexibility. Monthly internal data logging and historical index tracking make it work with Argus EMS from the moment it is installed.
| Nominal Flow (qp) | 0,6 / 1,5 / 2,5 m³/h |
| Max. Temperature | 90 °C |
| Min. Temperature Difference | Δθ ≥ 3 K |
| Accuracy Class | Class 2 (EN 1434), MID MI-004 |
| Energy Output | kWh heating + kWh cooling |
| Protocol | M-Bus EN 13757-2/-3 + Wireless M-Bus / LoRaWAN |
| Connection | Via an M-Bus TCP gateway (Argus EMS compatible) |
| Battery | ≥ 11 years |
| Body | Brass |
| Connection Compatibility | A1 · IST · M60 · PCC · TE1 |
| Protection Class | IP54 |
| Standards | EN 1434, MID 2014/32/EU Annex MI-004 |
The zelsius C5-ISF connects to Argus EMS over M-Bus (EN 13757) two-wire meter loop, and because a ready register template ships with the platform you do not have to work out a point map on site. The field agent polls the device every 60 seconds by default, writes the reading into a local queue first and then forwards it to the server over MQTT/TLS; nothing is deleted before the server acknowledges it. Hourly and daily summaries are derived from these raw readings, and the consumption and cost screens are fed from the same series.
| Protocol | M-Bus (EN 13757) two-wire meter loop |
| Connection path | The M-Bus loop is read through an M-Bus TCP gateway |
| Default polling period | 60 seconds (field agent) |
| Points in the ready template | 12 registers |
| Consumption calculation | Difference of the heat energy index (kWh) over the period |
| Data assurance | Local queue plus server acknowledgement; nothing is deleted before it is confirmed |
It measures the energy carried in a heating or cooling circuit, evaluating flow together with the supply/return temperature difference. In buildings with central systems this is the measured basis of heat-cost allocation.
The M-Bus loop is two-wire and meters connect in parallel on the same pair, so no dedicated cable is pulled per meter. Loop length, conductor cross-section and the number of meters on the loop are assessed together, because an M-Bus gateway can only drive a limited load. Meter addresses (primary/secondary) are verified one by one during commissioning.
Explore the system with your own data in a demo session.