Hi everyone,9
I just got a ESPHome wifi probe for my freezer and over the last 2 days I noticed a trend that it goes from its normal -20°C setting up to -10°c, it seems to do this every 12 hours. Because it is so consistent this looks like normal behaviour but just checking with others. Is this part of the self defrosting cycle of some kind? and if so how does dropping to -10°c do that?
Where have you placed the probe?
“Defrosting is controlled by an electric or electronic timer. For every 6, 8, 10, 12 or 24 hours of compressor operation, it turns on a defrost heater for 15 minutes to half an hour.”
Wikipedia…
That’s why you might find some cheap freezer has better energy class than top ones.
The ESPHome unit is outside and a long probe is inside the freezer at the back…
Ahh so the temp in the freezer would go up because the electric heater is hot enough to melt the frost on the walls but only enough to drop the temp by 10°c that makes sense…
this seems like what it is. I had an alarm on the freezer to let me know if it was ever above -10c and it kept going off. I’ll have to adjust that to say either -5 or state that has to be below there for a certain amount of time…
things you don’t know about your hardware till you start monitoring it!!
Move the probe further from evaporator/condensor plate if want to be measuring the temp of the freezer contents
Give it a time condition, above -10 more than 1h
Residential refrigerators/freezers defrost cycles are all programmed differently by each manufacturer. Whatever is cheaply done is what they will choose to control the cycle. You can’t count on a set schedule but you can try to plan for the spike and adjust alarms around that. If you watch your graph of the temps you can see a pattern. How high does it go up and for how long. You can’t count on a set time as that will drift away even if you guess close. For this example freezer, I’d generate an alarm if it went over 0F for >60 min.
