The record
Trust is a number, not a promise.
Every refrigerator claims a temperature. Kelvin keeps the receipts.
Measurement
One sensor tells you what one spot is doing.
Most compact refrigerators measure a single point, usually near the cooling plate, which is the coldest place in the cabinet. Kelvin uses two probes, forty millimetres below the ceiling and forty above the floor, each offset from the evaporator wall so they read air rather than metal.
The difference between them is the number that matters. If the top and bottom disagree by more than a degree and a half, something is wrong, and the app says so.
Record
Thirty days, stored on the unit.
Kelvin samples every thirty seconds and writes every five minutes to onboard flash. Not to a server — to the appliance. If your network drops, logging continues, and the gap fills in when it reconnects.
The history can be exported as a PDF. Nothing is smoothed, interpolated, or quietly cleaned up. Gaps appear as gaps.
Failure modes
The honest part.
Kelvin holds under eight degrees for about two hours with the door closed. It records the outage and tells you the peak temperature reached when power returns. It does not pretend nothing happened.
Refrigeration and logging are entirely local. The unit has never needed a server to be a refrigerator, and it never will.
If the two probes disagree for fifteen minutes, Kelvin flags the period as unverified rather than showing you a number it cannot stand behind.
Engineering
Thermoelectric cooling was never going to work.
Most small refrigerators in this price range use a Peltier module, which cools by a fixed offset from the room. On a warm afternoon that offset is not enough, and the cabinet drifts with the ambient temperature.
Kelvin uses a variable-speed compressor and isobutane, the same approach used in pharmaceutical cold storage. It costs more, it weighs more, and it holds the band from ten degrees ambient to thirty-two.
Not yet shipping
Kelvin ships in 2027.
Join the waitlist to see it first. No marketing beyond that.