SENSE
Measure the
temperature.
A wired sensor runs from the case, through the edge of the fridge door, and into the fridge compartment. It measures the temperature inside for the display and alarm.
REFRIGERATOR TEMPERATURE MONITORCONRAD CHALLENGE / INNOVATION PROJECT
Fridge
monitoring.
01 / 12TEMP
DEVICE ILLUSTRATION
DEVICE ILLUSTRATION
An external display for fridge temperature.
An audible alarm when it becomes unsafe.
AUDIBLE ALARM
OUTSIDE-MOUNTED DISPLAY✳AUDIBLE TEMPERATURE ALERT✳POWERED BY 2 AA BATTERIES✳WIRED TEMPERATURE PROBE
Fridge temperature
can go unnoticed.
Food and refrigerated medicine can be affected when a fridge is not kept at the right temperature. Checking a thermometer inside the fridge means opening the door and remembering to look at it.
12temp puts the temperature reading on the outside of the fridge and adds an audible warning. Our target users include households, clinics, and hospitals, particularly in areas with unreliable power.
02 — HOW IT WORKSSCROLL THROUGH THE DEVICE ↓
01 / 03
Measure the
SEE
Read it without
opening the door.
Adhesive mounting strips attach the case to the outside of the fridge. The screen shows the temperature inside, so users can check it without opening the door.
HEAR
An audible
temperature alarm.
The buzzer starts beeping as soon as a reading exceeds the alarm threshold, with no added delay. The final temperature threshold has not yet been set.
+
+
EXTERNAL DISPLAYCONCEPT ILLUSTRATION / NOT FINAL HARDWARE
TEMPERATURE DISPLAYTemperature reading
Temperature reading
and alert state.
The buzzer begins beeping on the first reading above the configured limit. This example shows the display and alert states; the final alarm threshold is still being decided.
12TEMP / DISPLAY EXAMPLEMONITORING STATE
3.5°C
The display shows the fridge temperature.
ILLUSTRATIVE READINGS · NOT LIVE DATA · SOUND NOT PLAYEDBattery powered.
Mounted outside.
Two AA batteries
The batteries are housed inside the case. Estimated battery life is 6–12 months per pair.
Adhesive strips
The case attaches to the outside of the refrigerator with adhesive mounting strips.
Wired probe
A wire runs from the case through the edge of the fridge door to the sensor inside the compartment.
03 — PROTOTYPE TESTINGCATAVIÑA, MEXICO ↗
Three prototypes
installed in Cataviña.
Our team tested a prototype and installed three units in Cataviña, Mexico, with help from renewable energy nonprofit GRID Alternatives.
Device components & project detailsFIELD NOTE / 00103PROTOTYPES
INSTALLED
INSTALLED
CATAVIÑA
BAJA CALIFORNIA, MEXICOPROTOTYPE
INSTALLATIONS
BAJA CALIFORNIA, MEXICOPROTOTYPE
INSTALLATIONS
Who the device
is designed for.
Households
People who need to monitor the storage temperature of food or refrigerated medicine at home.
Clinics & hospitals
Care settings that store refrigerated supplies. Clinics and hospitals are target users identified in our project plan.
Community partners
Nonprofits and local clinics are our planned first customers and distribution partners, helping the device reach the people they serve.
05 — THE PROJECTThe device
The device
and the project.
We are developing 12temp for the Conrad Challenge. The device combines a temperature sensor, an external screen, and an audible alarm in a mountable case.
01 / Product & engineering+
Our component plan includes an Arduino Nano, a temperature sensor, a screen, an audible warning, and printed circuit boards.
The electronics and two AA batteries sit inside a white, 3D-printed case. Adhesive mounting strips hold the case on the outside of the fridge. A wired probe passes through the edge of the door into the fridge compartment.
02 / Battery power+
12temp runs on two AA batteries inside the case. Estimated battery life is 6–12 months on one pair of batteries.
03 / Business model+
We plan to sell the device and pursue grants to support development. Our initial distribution plan is to work with nonprofits and clinics that already serve our target communities.
The main costs are the electronic components, printed circuit boards, 3D-printed case, and shipping. Our current case estimate is $2.03 per enclosure; this is not the cost of the complete device.
04 / Project goals+
We plan to track devices sold, households reached, and financial performance to assess distribution and operating costs.
Our initial focus is reaching people who need to monitor refrigerated food or medicine in areas with unreliable power.