In cold storage, the margin between a normal week and a very expensive one is measured in degrees and hours. A compressor fails on a Friday evening. A door doesn’t latch properly after the last pallet goes in. A defrost cycle hangs. In each case the room drifts quietly out of range, and whether you lose a load depends entirely on one thing: how quickly somebody found out.

That is why temperature logging and alerting have become baseline practice rather than a nice-to-have — and why a growing number of operators run a second, independent device alongside whatever their equipment came with.

Logging is what turns a claim into a fact

Continuous temperature logging does two jobs, and they’re different enough to be worth separating.

Assurance — knowing, not assuming

A spot check tells you the temperature right now. A log tells you what the temperature has been — overnight, over the weekend, during the heatwave, while the unit was being serviced. That history is the difference between believing your cold chain held and being able to demonstrate it.

It also surfaces the slow problems that no single reading will ever show you: the room that now takes twice as long to recover after a door cycle, the gradual upward creep that means a seal or a charge needs attention, the one freezer that always runs warmer on the top shelf. Those are maintenance decisions you can only make with data behind you.

Audit reporting — having the record when someone asks for it

Customers, insurers, auditors and buyers increasingly want evidence, not assurances. When a complaint lands or a claim is filed, the operator who can produce a documented temperature and humidity history for the period in question is in a completely different position than the operator who can’t.

With Watchman, logs are downloadable as Excel files from the portal. A subscription keeps up to 60 days of history in the portal and can email you a daily Excel file of that day’s logs, so you can archive the record as far back as your customers or your retention policy require. There’s also an API if you want to pull readings into your own systems.

Watchman gives you a documented temperature and humidity history that helps you keep the kind of logs auditors ask for. We don’t claim any formal regulatory certification on your behalf — your compliance obligations remain yours to define.

Alerting is what prevents the loss in the first place

Logging proves what happened. Alerting is what stops it happening. A record of a freezer rising to 20°F over a holiday weekend is useful for the insurance claim and useless for the product.

The failures that cost real money are almost always the ones that occur when nobody is on site. Watchman logs hourly by default, and every 15 minutes on a subscription. A sudden swing of temperature triggers an immediate log and alert regardless of your logging interval — and in a freezer, a fast rise is exactly the signature of the failures you most want to catch early.

Email alerts to the account holder are included at no cost. A subscription adds text alerts to a US or Canada number, alerts to up to three email addresses, and a daily log-snapshot email. Just as importantly, it enables the Watchman Health Check, which tells you when a unit loses power or internet connectivity. In cold storage that matters more than almost anywhere else: a monitoring device that has gone quiet because the site lost power is reporting the single most urgent thing it could possibly report, and you need to be told.

You already have a built-in monitor. Here’s why operators add a second one.

Most cold storage equipment ships with an integrated temperature display, controller or alarm, and those are genuinely useful. But they share a structural weakness: the thing doing the controlling is also the thing doing the reporting. If the controller’s sensor drifts, the board fails, or the unit loses power, the same fault that caused your problem can also silence the thing meant to warn you about it.

An independent device has no such dependency. It’s a separate sensor, on separate power, reporting over a separate path to a system your equipment vendor doesn’t control.

This isn’t about distrusting your equipment. It’s the same logic as a smoke detector in a building that already has a sprinkler system: two independent layers, so that no single failure takes out both your protection and your warning.

One dashboard across every site and every unit

The redundancy argument is what gets operators to install the first Watchman. Centralization is what makes them install the rest.

A typical cold storage operation is a patchwork: walk-ins of different ages, reach-ins from three vendors, a blast freezer, a couple of refrigerated trailers, maybe several sites. Each with its own controller, its own interface, its own way of showing a temperature — and no way to see them together.

Watchman units all report into the same pp-Code portal and the Watchman.Online app, regardless of what equipment they’re attached to or which site they’re at. One account manages multiple units, so you get:

• Every room, cabinet and site on a single screen, in the same format
• Consistent alert rules you set, rather than whatever each vendor’s controller happens to offer
• A uniform log format across mixed equipment, which makes audit reporting straightforward instead of a reconciliation exercise
• Alerts to the people who should get them — with a subscription, up to three email recipients, an SMS number, and portal access for additional users such as a site supervisor, maintenance contractor or QA lead
• The ability to compare units against each other and spot the one that’s degrading

Deploying in a cold environment

A few practical notes specific to cold storage:

• Use a probe for the cold space. The Temperature Probe and Probe Addon options let you place the probe inside the freezer or chiller while the unit itself sits outside — which keeps the electronics and the WiFi connection in a friendlier environment.
• Monitor the point that matters. Put the probe where product actually sits, not next to the evaporator outlet, where you’ll read the coldest air in the room rather than the condition of the load.
• One per enclosure, not one per building. Separate rooms and cabinets fail separately, so they need to be measured separately.
• Check WiFi at the install point. Watchman uses 2.4GHz WiFi with no gateway required, working up to about 75ft from the access point and within 50ft for a consistently stable connection.
• Consider the related risks too. The product line also includes water, gas, noise and humidity sensing, plus a relay option — useful around compressor rooms, condensate, and humidity-sensitive storage.

Buying for a cold storage operation

Temperature Probe Units start at $45.95, with an optional subscription at $2.49 per month or $19.99 per year per unit, or a one-time lifetime BuyOut at $49.99. Standard monitoring and email alerts need no subscription.

That said, for cold storage we’d generally encourage the subscription on every unit, because the features it unlocks are the ones that matter most in this setting: 15-minute logging, SMS alerts, multiple recipients, the daily log export for your audit record, and the Health Check. For operators running many units across multiple sites, a lease arrangement is also available, which bundles all features with product and service coverage — worth a conversation if you’re deploying at scale.

Every unit comes with a 30-day money-back guarantee, and a 1-year warranty for subscribed customers (90 days otherwise).