Cold Storage Monitoring & Alerts
Continuous temperature monitoring for walk-in coolers, freezers, blast chillers, and controlled-atmosphere rooms — across every facility, with audit-grade HACCP / FDA / USDA records and threshold alerts that wake someone up before product spoils.
Running an HVAC fleet instead? See the HVAC page.
The Problem
A single excursion costs thousands in spoiled product
Coolers and freezers fail without warning — compressor lockout, defrost cycle stuck, door left open overnight. By the time someone notices, the inventory is already at risk.
Manual temperature logs are unreliable and labor-intensive
Walking around to log each cooler temperature on a clipboard is hours per week, and produces gaps overnight and on weekends — exactly when failures happen.
No remote visibility across multiple locations
Multi-site operators (cold-storage chains, regional food processors, restaurant groups) have no single view of every walk-in across every facility.
Manual records fail inspections
FDA, HACCP, and USDA inspectors expect continuous temperature records with timestamps. Paper logs and spot-checks are not audit-grade.
How LoopString Solves It
On-edge monitoring that survives outages
A Raspberry Pi per facility reads every cooler and freezer probe locally and runs threshold logic on-device. Process control survives ISP outages, power flickers, and cloud incidents.
Multi-cooler, multi-location dashboard
See every walk-in, freezer, blast chiller, and controlled-atmosphere room across every facility on one screen. Sparkline trends per cooler. Grouped by location.
Threshold + door-open alerts before product spoils
Configure alert thresholds per cooler with hysteresis to avoid false positives. Anomaly detection flags compressor failures via rolling-baseline drift. Escalation chains wake the right person.
Continuous, audit-grade compliance records
Every reading is logged with a timestamp and exportable as a HACCP / FDA / USDA-style PDF report. Inspector-ready records, not clipboards.
Built for these cold-storage operators
Cold-storage chains
Multi-site walk-in cooler + freezer monitoring across every facility, with grouping and RBAC for facility managers.
Food processors
Continuous-record temperature monitoring on raw-material coolers, finished-goods freezers, and blast chillers.
Restaurant + grocery chains
Walk-in, prep-fridge, and reach-in monitoring across every location, with regional-manager dashboards.
Controlled-atmosphere storage
CO₂ + O₂ + temperature monitoring for fruit / produce CA rooms — apple, pear, kiwi, banana ripening.
Biotech + pharma cold chain
Per-unit temperature and humidity records for samples, vaccines, and biologic-storage freezers (-20°C / -80°C).
Cold-chain logistics
Distribution-center cooler + reefer-staging-area monitoring with audit-ready exports for chain-of-custody compliance.
Hardware You'll Use
DS18B20
Waterproof temperature probe for walk-ins and freezers
1-WireSHT31
Combined ambient T + relative humidity for staging areas
I²CMH-Z19B
NDIR CO₂ sensor for controlled-atmosphere rooms
UARTDoor switch
Magnetic reed switch for door-open alerts
GPIO
Free tools for this work
Dew Point Calculator
Watch the dew-point spread to stop condensate drip and coil frost before they start.
HACCP Temperature Log
Free printable + CSV log template and a guide to log frequency and corrective actions.
Temperature Mapping Guide
How to validate a cold room or warehouse and find the hot and cold spots.
Frequently asked questions
- Can LoopString monitor multiple cold rooms or freezers from one dashboard?
- Yes. Each room is a device or card with its own temperature limits, and a fleet/group view rolls them up so you can watch a whole facility at a glance. Alerts are per-room.
- Does it meet HACCP temperature-logging requirements?
- LoopString keeps timestamped temperature history and generates HACCP/FDA/USDA-style reports, plus alert-event records with acknowledgements. The record lives in the cloud; the Pi keeps logging locally if the link drops so there are no gaps.
- How fast will I know if a freezer starts warming?
- Threshold alerts fire within seconds of a reading crossing your limit, over the notification channels you configure, and a door-open or power-failure sensor can trigger its own alert before the temperature even moves.
Ready to put eyes on every cooler?
Start free — no credit card required.