Need better freezer solution

I’m working on lowering freezer energy.

A freezer is a BIG home energy consumer. Worldwide they are a huge electricity consumer. So to help slow global warming, it’s a very important appliance to make more efficient I think.

Fortunately it’s also a pretty good thermal battery, and I want to use that feature to save power. In particular, during the daylight hours I want to power my freezer with solar, and at night let its insulation and thermal mass keep things frozen. We can also back this up with AC power if needed, like possibly during hot summer nights.

This can avoid the huge cost of having to power the Freezer with batteries overnight. (We now run on solar by day and batteries by night. I’m trying to get fully off of carbon fuels, so am living on Lithium Ion at night, and am trying to only use them as much as necessary as usage wears them out.)

A good freezer solution requires accuracy and reliability.

First it needs a pair of accurate IoT low temperature sensors, two fully redundant circuits, and a smart, reliable, monitored power switch/relay. Problems need to be promptly reported, like if power is not flowing, or if an unexpected high temperature occurs.

I’ve searched all over for off-the-shelf solutions and have yet to find what I think are appropriate smart reliable thermometers that will work with Home Assistant and use either ZigBee (my preference), Wi-Fi (without an additional hub), or Z-Wave.

In particular freezer thermometers need to read freezing temperatures. And freezer thermometers need to keep their electronics out of the freezer to avoid corrosion, but instead can run a small signal wire into the freezer compartment with the actual thermister. And I think the temperature sensors need to be AC powered, so one doesn’t have to worry about their battery, ever.

I can see that many people are trying to monitor their freezers, and some are trying to use thermometers intended for interior conditioned space which don’t read low enough for a freezer and aren’t setup to avoid the corrosion. In other words, people are putting the electronics in the freezer and hoping for 6 months of life, rather than 16 years of service.

I’m one of the old guys using automation having had an Elk Products security/automation system running for 20 years. I’ve used it to monitor my freezer and report high temperatures for the past 10 years or so, and over that time it’s saved me a few times from a full thaw. I’m in the process of replacing my old Elk system with HA. I love HA and that Z2M Zigbee has TCP reliability. Most everything works great, but the freezer still needs a solution.

So I’m looking for other serious clever people here to help come up with a really good solution for freezers (starting with mine and yours), and moving towards technology that could be used globally to save energy.

I’m using one of these to monitor my fridge/freezer temps:
Amazon.com: Ambient Weather WH31P Water Proof Thermometer Probe Sensor : Patio, Lawn & Garden

I used it in the pool, but I needed to find a replacement for it after I got a pool robot that didn’t get along with the probe’s cable dangling in the water - so I moved it to the fridge/freezer.

It is currently hooked up to my Ambient weather station and reports and alarms that way, but I can also see it on my rtl_433 receiver - I know it’s not Zigbee or Z-Wave, but the battery life is great and so I just wanted to throw it out there for food for thought.

There’s also an inside-the-fridge/freezer version, but I have no experience with it:
Amazon.com: Ambient Weather WH51RF Refrigerator Freezer Sensor : Patio, Lawn & Garden

Probe is in the right direction. Thank you for the info on this.

But overall not what I’m seeking. I want something for HA without some other hub involved, which also adds cost and allows more things to go wrong.

I might have to try and custom engineer it if I can’t find it off the shelf.

(BTW I have a similar no-moving-parts Tempest weather station. Works great w/ HA!)

1 Like

Understood - lot’s of DIY stuff out there based on e.g. ESP DevKits.
Good luck!

1 Like

What hub?
You never need to use the manufacturers hub. Just get the appropriate dongles- one for Zigbee and one for Z-wave.

I just chuck a Zigbee thermometer in my fridge, but for my freezer I use a Wemos D1 Mini and a Dallas DS18B20 sensor on a 1M long micro cable taped to the inside of the freezer. The DS18xx are notoriously inaccurate, and the cheap ones are counterfeits. Since 0°C is the only place I needed accuracy that’s where I calibrated it. If the temperature goes above 0°C for five-minutes, I get a notify.

1 Like