Cold room and cold storage temperature monitoring

A cold room is not one temperature. It is warmer by the door, colder by the evaporator, and in the far corner is where the thing nobody sees happens. The system places several sensors in the room on a single cable, reports over cellular from a controller that stays outside, and alerts the moment one point leaves its range.

A cold room is not one temperature

One thermometer by the door tells half the story. Several sensors on one cable tell all of it.

-40 to +80°C
Measurement range
±0.3°C
Temperature accuracy
RS-485
Several sensors on one cable
Wi-Fi / 4G-LTE
Wi-Fi or cellular, from outside the room

The door was left open

A truck being unloaded, a forklift stuck in the doorway, someone who forgot. The sensor by the door shows the rise first, and the allowed excursion duration you set separates a normal fifteen-minute unloading from a door left open for an hour.

An evaporator icing up

The temperature does not jump, it creeps. The room's history shows a slow rise over days before the first alert arrives, and that is the moment to book a defrost or a technician, not after the stock is thrown out.

A warehouse with several rooms

temperature and humidity sensors are addressable on an RS-485 bus up to 2,000 m long, so one controller outside the rooms covers several rooms and several points in each. Every sensor gets its own name, range and history on the dashboard.

A record per room

Every reading is stored with a timestamp. Before an inspection, or before a dispute with a customer over a delivery that arrived warm, you export the room's history for the requested period to Excel.

What gets installed, and where

Sensors inside, controller outside, one cable between them.

  1. 01

    Sensors inside the room

    A temperature and humidity sensor in a sealed or IP67 housing, one by the door and one in the far corner, on the same RS-485 cable. For a freezer room or a point inside product, a stainless IP68 temperature probe that measures down to -55°C.

  2. 02

    Controller outside the room

    The Omni Genesis controller hangs on the outer wall, at normal temperature, and takes the sensor cable through a pass-through in the panel. It reports over Wi-Fi or 4G-LTE with a SIM included in the subscription, runs on a rechargeable battery and connects to a power adapter where a socket exists.

  3. 03

    A range and an excursion duration per point

    On the dashboard each sensor gets a name, a minimum, a maximum and an allowed excursion duration. Meat room between 0 and 2°C, vegetable room between 4 and 8, freezer room below -18. The reporting interval is set per controller, from one minute up.

  4. 04

    Alert and history

    An excursion that outlasts the allowed duration sends an alert by SMS, email, phone call or push notification to every user on the account. The history of each point is stored in the cloud and exports to Excel.

For individual refrigerators and freezers in a kitchen or shop, see the refrigerator and freezer temperature monitoring system.

Wireless temperature monitoring for a cold store with metal walls

An insulated panel faced with metal on both sides is a small Faraday cage. A wireless transmitter placed inside a cold room loses its signal the moment the door closes, and many systems solve that by mounting the transmitter next to the door, which is the least representative point in the room. Here the wireless part is the controller outside, and the part inside is wired.

The controller reports over the cellular network with a SIM included in the cloud subscription and runs on a rechargeable battery. A warehouse with no Wi-Fi, a warehouse with power cuts or a rented warehouse where the network is off limits are all monitored the same way.

Types of room

Same installation, different ranges.

Cold storage and distribution

Several rooms at different temperatures on one controller. A history per room when a customer claims a delivery arrived warm.

Freezer rooms

A temperature probe down to -55°C. An allowed excursion duration that covers a scheduled defrost without missing a stopped compressor.

Packing houses and pre-cooling

Pre-cooling of produce after harvest, where the time to target temperature decides shelf life. Temperature and humidity together.

Ripening rooms

Bananas, avocados and mangoes, where relative humidity matters as much as temperature. The temperature and humidity sensor measures both at the same point.

Technical specifications

Temperature and humidity sensor, temperature-40 to +80°C, ±0.3°C @ 25°C
Temperature and humidity sensor, humidity0-100% RH, ±3% RH
Temperature and humidity sensor, housingsVented, sealed, stainless, sintered, IP67
Sensor busRS-485 Modbus RTU, up to 2,000 m
Temperature probe-55 to +125°C, ±0.5°C, IP68
ControllerOmni Genesis, 4 ports, rechargeable battery, 6-32V DC input
ConnectivityWi-Fi / 4G-LTE (SIM included), Bluetooth
Reporting intervalYour choice, from one minute up
ExportExcel, per sensor and per period
Warranty24 months on the controller, 12 months on sensors

Questions about cold room temperature monitoring

How many measurement points does one cold room need?

A small room is covered by one point away from the door and the evaporator. A room of several tens of square metres gets at least two, one near the door and one in the far corner, because the difference between them is exactly what an inspector asks about. temperature and humidity sensors are addressable on an RS-485 bus, so several sensors in the same room sit on a single controller port.

How does the cable get into the room?

Through an existing pipe pass-through in the panel or a small drilled hole sealed after the cable is pulled. The controller stays outside at normal room temperature and the sensor inside. A wired link through an insulated panel is more reliable than any transmitter trying to broadcast from within.

Does the warehouse need Wi-Fi?

No. The controller reports over the cellular network with a SIM included in the cloud subscription. In a cold store with metal-faced panel walls that is usually the more reliable option as well. Wi-Fi is available for anyone with a stable network near the controller.

What happens in a power outage?

The controller runs on a rechargeable battery, so measurement, logging and alerts continue when the warehouse loses power. Readings are stored and sent, and the history afterwards shows exactly when the room started warming and how fast.

Can humidity be monitored as well?

Yes. The temperature and humidity sensor measures temperature and relative humidity in one body, from -40 to +80°C and 0 to 100% RH. In ripening rooms, in pre-cooling rooms for fresh produce and in vegetable cold stores it is the second variable that decides shelf life.

Tell us about your cold store

How many rooms, at which temperatures, and where the controller can sit. We will scope the measurement points with you.

Send a message instead

The far corner of the room, on your screen

Several measurement points per room, an alert on excursion, and a history that is ready for inspection.

Technical capabilities

The facts an integration plan needs. Full measurement range and accuracy specifications are on every product page and datasheet.

Sensor protocols

  • RS-485 Modbus RTU
  • SDI-12
  • I2C
  • Analog
  • 1-Wire

Connectivity

  • 4G LTE cellular (optional)
  • Wi-Fi
  • Bluetooth

Power and enclosure

  • Solar powered
  • Battery operated, deep-sleep cycle
  • IP65 rated controllers

Data and integration

  • Cloud dashboard with real-time alerts
  • Configurable reporting intervals
  • REST API access