Refrigeration temperature sensor placement

[rubberduck]

Hi everyone,

Had to find good information on this. I'm trying to understand a bit about fridge/freezer temperatures and where the proper place to put the sensor is. For example... today i was trying out a new freezer, the temp sensor is located less than 3 CM away from the bottom of the plate. Using a lazer temp meter, the sensor was -7C while the evaporator plate was -20 C (rest of the box was showing -20. I had the controller set to -15 but it was just not able to get there.

The fridge is the same issue. The temp prob is reading 2C but when i shine the light in to the back of the fridge its saying 15c (which i have a hard time believing - think this has to do with warm air rushing in when i open the door.

Any thoughts on where these reading should be taken from? And what the temperature on the plate should be V in the space within the Fridge/Freezer?

Thanks!

[sailorboy1]

it takes some trial and error. I have my frig side set to 36-39F, which is measured at the back along the wall and it probably is at a "warm" spot, but is running about a 50% cycle time. Things on the bottom would freeze till I added a fan and changed the main fan to run all the time. I have my freezer set to 11-16F and it is measured at top of plate about 1cm inside, so that again is at the top of the box. I found setting lower used a LOT more power and even at this setting the food in the mid to bottom of the box was rock solid.

FYI I originally had a spillover system, which is just a freezer with a passage between it and the frig with a fan. Last year I added a small frig unit and sealed the holes. Am getting a LOT better cool performance now at the same power use that the single spillover system did

[Dsanduril]

In the industrial freezers where we set up monitoring all of the probes are placed in a small glycol bath to get rid of the air flow effects from opening the cabinets. You won't get instantaneous reads this way, but you will get something more representative of stuff actually stored in the fridge/freezer. You can pick up little bottles of glycol designed to be have a probe inserted for a few dollars.