Every walk-in fridge and freezer in a central kitchen sends a reading every 5 minutes. A unit running warm for 20 minutes triggers a WhatsApp alert to the chef on shift, escalates to the head chef if ignored and lands in a daily HACCP log.
Typical results
5 min
Between readings from every fridge and freezer
20 min
Above 5°C before the chef on shift is alerted
Daily
PDF temperature log filed for inspectors
Figures reflect typical results for this kind of automation.
The challenge
The central kitchen runs six walk-in fridges and freezers that hold stock for four branches. Temperatures are written on a paper sheet twice a day, so a compressor that fails at midnight is found at 6 AM with the stock already lost. Before inspections, someone spends hours tidying the sheets and filling in missing corrective actions.
Before and after
Hours per week on manual temperature logs
−86%Minutes to detect a failing fridge
−96%Spoiled stock incidents per quarter
−67%The automation
Wireless sensors in each walk-in fridge and freezer send a reading every 5 minutes to a monitoring sheet. If a fridge stays above 5°C for 20 minutes, the chef on shift gets a WhatsApp alert with the unit, the temperature trend and a corrective-action checklist. If nobody acknowledges within 15 minutes, the head chef is alerted. Short spikes from door openings are ignored. Each day a PDF log with all readings, alerts and actions taken is filed for health inspectors.
How it works
- 01
Readings every 5 minutes
Wireless sensors in each walk-in fridge and freezer send the temperature to the monitoring sheet.
- 02
Threshold check
A fridge above 5°C for 20 minutes in a row triggers an alert, while short spikes from door openings are ignored.
- 03
WhatsApp alert to the chef
The chef on shift gets the unit, the temperature trend and a corrective-action checklist.
- 04
Escalation
If nobody acknowledges within 15 minutes, the head chef receives the same alert.
- 05
Daily HACCP log
Readings, alerts and actions taken are compiled into a dated PDF log and filed for inspectors.
Starts from
- Wireless fridge sensors
Delivers
- WhatsApp alert to chef
- Escalation to head chef
- Daily HACCP PDF log
The impact
A failing fridge is caught within about 20 minutes, day or night, instead of at the next manual check. Spoiled stock incidents drop from around 3 a quarter to 1, the team saves about 3 hours a week of manual logging, and the HACCP records are complete whenever an inspector asks.
Questions about this automation
What counts as an alert, and what is ignored?
An alert fires only when a unit stays above its limit for 20 minutes in a row: 5°C for fridges, or warmer than minus 18°C for freezers. Brief spikes during deliveries or door openings recover before then and are recorded without an alert. Each unit's limit and delay can be set separately.
How does the chef acknowledge an alert?
The WhatsApp alert has a one-tap reply to acknowledge it, followed by the corrective-action checklist: check the door seal, move stock to another unit, call the technician. The chosen actions and the time are written to the log. If no one replies within 15 minutes, the head chef gets the same alert.
What does the inspector's log contain?
Each daily PDF lists every unit with its readings, minimum and maximum, any alerts, which role acknowledged them and the corrective action taken. The files are stored in a dated Google Drive folder, so a month of records can be printed or shared in minutes. This is a multi-step build, usually rolled out in stages.