How to choose a temperature monitoring system for a multi-store chain

To monitor hundreds of freezers, fridges and walk-ins across many stores, you want a complete system with one wireless sensor per unit, one connection per store and a central platform with alerts that someone has to close, not WiFi thermometers or loose sensors. The technology matters less than it seems; what decides whether it works is how it is installed, what happens when the internet goes down and whether alerts reach the person who fixes the problem.

The four possible technologies

Almost every system on the market uses one of these four ways to get the reading from the sensor to the internet:

	WiFi sensor	Cellular sensor	LoRaWAN with gateway	Bluetooth (BLE) with gateway
Connections to pay for	None extra, but it uses the store network	One per sensor	One per gateway	One per gateway
Sensor battery	Short: WiFi draws a lot of power	Short: the modem draws a lot of power	Years	Years
Depends on the store network	Yes, and on its password	No	Only the gateway, which can use 4G	Only the gateway, which can use 4G
Range	The store WiFi’s	Cellular signal, which often fails inside metal walk-ins	Very long: kilometers outdoors	Tens of meters: covers a retail store with 1 or 2 gateways
Sensor cost	Low to medium	High, plus a line for each one	Medium to high	Low
Best for	A few units in a single store	Equipment that moves: trucks, containers	Very large or outdoor sites: farms, industrial parks	Retail stores, warehouses and walk-ins: the range is enough and it is the most cost-effective option

For a store chain, the two gateway options scale best: one connection per store, batteries that last years and nothing to configure on each store’s network. Between the two, Bluetooth Low Energy is the better fit for retail stores: one or two gateways cover the whole store, the sensors cost less and the total cost is lower. LoRaWAN’s range of kilometers goes unused inside a store; it pays off when you need to cover long distances, such as industrial sites or farms, where it justifies more expensive sensors.

What the system needs to do

With 500 units, nobody watches 500 temperatures. The system has to do the work:

1. Install without touching the units. If the controller has to be replaced or the unit opened, every sensor is a service call. A self-contained sensor goes in in seconds and works with any brand, including supplier-owned freezers.
2. No gaps in the data. The sensor and gateway have to store readings when the internet or power goes down, so the history has no gaps. How that works is in the guide to large-scale monitoring.
3. Alerts that someone closes. The alert has to reach the store manager with instructions, escalate to the next level if the problem continues and stay on record as a ticket until it is closed. The full workflow is in the guide to temperature control for franchises.
4. Every store on one platform, with users by store and by role: the store manager sees their units, the area supervisor their region and head office the whole network.
5. Records that hold up in audits. History per unit, alerts with who handled them and when, exportable reports and sensors with a calibration certificate.
6. More than temperature, if needed. Humidity in warehouses and rooms, door-opening counts, and alerts for power outages, gateways that lose their connection and low batteries.
7. Scale without changes. Going from 20 to 200 stores should not change the architecture or multiply the connectivity cost per sensor.

How to work out the real cost

Comparing only the sensor price is misleading. The total cost of a multi-store system adds up:

• Hardware: sensors and gateways.
• Connectivity: one line per sensor versus one per store makes a huge difference at scale. With 500 units in 20 stores, that is 500 lines against 20 to 40.
• Installation: seconds per unit, or a service call per unit.
• Platform and alerts: the monthly fee, whether it charges per user and whether WhatsApp or SMS alerts are included.
• Maintenance: how often batteries need replacing and who does it.

What to ask the vendor before signing

• What does it cost per unit per month for my number of units, and what is included?
• Do the units have to be modified or their controller replaced? Who installs, and how long does it take per store?
• How many connections will I pay for: one per sensor or one per store?
• How long does the battery last inside a freezer, in real conditions?
• What happens to the readings if the internet or power goes down over a weekend?
• Do alerts escalate if the problem continues? Are they recorded as tickets?
• Can I see every store on one platform, with users by store and by role?
• Do the sensors come with a calibration certificate? Have the records been presented in an audit?
• Does it integrate with our maintenance system or ERP?
• What is the largest deployment you have in operation, and with which customers?

How Alephius solves it

Alephius uses the option that works best in retail stores: Alephius Edge sensors that install in seconds without touching the units, take a reading every 15 minutes, have a 5-year battery and do not depend on the store network. If the internet or power goes down, the history has no gaps. Alephius Cloud shows every store with users by store and by role, and Alephius Assist notifies the store manager on WhatsApp or by email, guides them to fix the problem and escalates if the deviation continues, with a ticket that stays on record until it is closed.

A supermarket chain connected 600 sensors in 30 stores in 5 business days, and companies such as Día, McCain, Havanna and Aramark run on Alephius. The architecture is covered in detail in the guide to large-scale temperature monitoring, and the full solution in retail and cold chain.