I need some help finding a z wave freezer temperature sensor for my Vera. We just purchased a freezer and I would like to be alerted if the temperature should rise above a certain limit. Thanks for the help.
You might be hard pushed to find anything off the shelf. Any battery powered device would be out of the question unless it had an external probe that could drop into the unit.
Maybe a better idea would be to monitor it’s power consumption over time - observe a behaviour pattern and alert upon reasonable deviation of said pattern.
I think Autelis makes a probe type temperature sensor. It’s not Z wave, but they may help you get the values off of it via wget commands.
Actually, this sensor looks interesting and cheap:
This could be a viable solution -
I use a Fibaro door sensor and a waterproof DS18B20 to report my pool temerature. I’ve hardwired it to 3.3v power and it’s a very reliable sensor…
If you have wi-fi, and your controller is on the same subnet, you can easily make a sensor with a thermocouple and a Particle Photon or Arduino.
Thanks for all of your responses. I think using a wired probe might interfere with the seal of the freezer top door. The only affordable device I found without a wire going into the freezer is the AcuRite 00986A2 Refrigerator/Freezer Wireless Digital Thermometer. I just have to figure a way of tapping into the base unit with a Zwave switch that will alert my Vera if the freezer should drop below a preset temperature.
Im having a Fibaro Fgk-10x with a ds18b20 in my freezer. It reports temperatures well. Not sure how long the battery will hold. Ive only had it for a month.
I’m using a mysensors sensor that i built. running on 2 double A’s. for almost a year now.
check out mysensors
What is a ds2018b20?
I think he meant DS18B20. It’s a temperature sensor that can be connected directly to quite a few different systems that has excellent accuracy. Google DS18B20 and you’ll see many examples of it. There is most likely a point somewhere that you can thread the cable through without interfering with the door seal. I wouldn’t run it across the seal either. However, there’s usually a sensor or even a light that has wires running through a sealed up channel. You could add one (the cable is quite thin) and then reseal it. My pool sensor was constructed by drilling a hole big enough for the cable to pass through into a nylon pipe plug with threads matching the drain plug on my pool pump. I fed the cable through from the water side and put JB Weld in the well on the inside of the plug. Once the sensor was pulled down into the well and the JB Weld set up, I installed it into the pump housing. I did coat the entire sensor that contacts the water. Reason being that the sensor housing is already waterproof and stainless steel, but I have a salt water pool. Better safe than sorry…
If you want more advanced temperature reading, you can use Fibaro binary sensor, which allows you to attach up to 4 temperature sensors. You can put it inside in some waterproof housing, powered by i.e. 9V battery, or outside, as Mike Yeager suggested.
Also most of Qubino modules allow attaching temperature sensor, based on the same DS18B20 module.
When I played with Everspring 814 to understand how it works, I repeatedly shoved it into the freezer. From a distance of 10 meters, Vera saw him perfectly.
Netatmo external sensor, also often visited both the freezer and the iron cabinet, and has been living in the street for the third year with the first set of batteries.
And … you do not trust the manufacturer of freezers? It’s the “eternal” devaysy 
Personally, I’m more concerned about the presence of voltage in the outlet. Well, if it disappears, Vera will die and there will be an alert from Mikasa
I have two freezers - both with a wireless, battery powered sensor put into them. Don’t understand why people claim that won’t work. It works perfectly fine, and battery lasts more than a year.
According to Energizer, both NiMH and Alkaline batteries are OK down to -20C but will only give 20% capacity.
Alkaline can go lower (which I guess may be the case with freezers), but then with an even more significant capacity drop-off - graph on page 5 of this: http://data.energizer.com/pdfs/alkaline_appman.pdf
The limiting factor seems to be internal resistance and current capacity, which for a ZWave device isn’t a big deal they’re very low power.
You can try lithium, which have best performance in low temperatures. Just keep in mind that they have higher voltage when fresh than standard alkaline and because of that are not recommended for some electronic devices.
Which one are you using?
What temperature range will the Door Switch report? I see that the sensor DS18B20 temperature range is -55 ?c ~ +125 ?c
Also how quickly will it update a change in tempature?
Thanks
Jim
The door sensor reports whatever temperature it is given by the sensor. Mine has been set to report a change of about 2/10ths of a degree. I believe out of the box it reports about every 1 1/2 degrees F. As for how quickly it reports, as soon as the threshold is met, the sensor reports it back to the hub.