COMET H6420 CO₂ + Temperature + Humidity Controller with 2 Relays and RS485

COMET T6420 CO₂ + Temperature + Humidity including 2 Relays RS485

The COMET H6420 is an intelligent 3‑in‑1 climate controller with direct control functionality. It precisely measures CO₂ concentration (0–5000 ppm), temperature, and relative humidity – and automatically activates two powerful relays (e.g. for ventilation, air conditioning, window openers, or alarms) when thresholds are exceeded. In addition, a 3‑color LED indicator (green/yellow/red) and a loud acoustic buzzer immediately warn of poor air quality – perfect for fully automatic, energy‑efficient, and healthy room ventilation.

Whether in schools, kindergartens, offices, conference rooms, production halls, sports halls, or restaurants – the H6420 ensures optimal air quality at all times, without the need for manual intervention. Demand‑controlled ventilation saves up to 50 % in heating and cooling energy.

The RS485 interface with Modbus RTU protocol seamlessly integrates the H6420 into any building automation, BMS, or SCADA system. All derived humidity values such as dew point, absolute humidity, etc. are also available.

Its robust housing, maintenance‑free NDIR CO₂ sensor with automatic calibration, and a 3‑year warranty make the H6420 the top choice for professional indoor climate control.

Why the COMET H6420 is No. 1 for automatic ventilation:

• 3 measured parameters: CO₂ (0–5000 ppm) + Temperature + Humidity
• 2 potential‑free relays (8 A / 250 V AC) – direct HVAC or ventilation control
• 3‑color LED + acoustic alarm – instantly visible and audible
• RS485 Modbus RTU – ideal for BMS and building automation
• Control by CO₂, temperature OR humidity – maximum flexibility
• Maintenance‑free thanks to automatic CO₂ calibration
• Dew point, absolute humidity, etc. integrated
• Large dual‑line display – switchable
• Simple wall mounting
• Warranty: 3 years

Technical Highlights:

• CO₂ measuring range: 0 to 5000 ppm (±50 ppm + 3 % of reading)
• Temperature: –30 to +60 °C (±0.4 °C)
• Humidity: 0 to 100 %RH (±2.5 %RH)
• Dew point: –60 to +80 °C
• Relays: 2 × potential‑free, max. 8 A / 250 V AC
• LED indicator: Green ≤ 1000 ppm | Yellow 1001–1200 ppm | Red ≥ 1201 ppm
• Acoustic alarm: Built‑in beeper, switchable
• Communication: RS485, Modbus RTU (standard)
• Power supply: 9–30 V DC or 24 V AC
• Protection class: IP30 (indoor use)
• Operating temperature: –30 to +60 °C
• Warranty: 3 years

Perfect for:

• Schools, lecture halls, and kindergartens
• Offices, open‑plan offices, call centers
• Conference and assembly rooms
• Sports halls, fitness studios
• Restaurants, canteens, catering areas
• Production and storage facilities
• Hospitals and waiting rooms
• Demand‑controlled ventilation systems according to DIN 1946‑6

Installation & Commissioning – done in minutes

Mount to the wall with two screws, connect relays and power supply, optionally connect RS485 – done. Switching points, hysteresis, and alarm delay can be easily configured using the free TSensor software or directly on the device.

Summary:

• Temperature, humidity, and CO₂ sensor with two output relays
• Green LED on: CO₂ 0 to 1000 ppm
• Yellow LED on: CO₂ 1001 to 1200 ppm
• Red LED on: CO₂ ≥ 1201 ppm

Scope of Delivery:

• H6420 unit
• User manual
• Traceable calibration certificate
• Free TSensor software for transmitter configuration