Freezer to fridge guys, need a recommendation please!

[Rednecktek]

So I had this BRILLIANT thought that if I got a chest freezer and just set the thermostat to 1 that it would hover right around the freezing mark....

Yeah, not so much... BUT having seen videos of people doing it I know there is some sort of magic relay/thermostat/probe/thingymabober out there that will go between the freezer's compressor/thermostat system and the wall to have it kick on and off at fridge temperatures.

Unfortunately I don't know the terminology involved to even start looking for that magic thermostat/contactor box.

I'm good keeping it all 110v so no inverters or low/high voltage combinations or anything, I just don't know what I'm looking for or what makes one better or worse?

Someone on here knows what I'm talking about, right? Wanna point a guy in the right direction?

Some maybe important details: It draws between 62-74 watts and only gets used 2 weeks a year at the family camping trip. It's a 7cf Magic Chef that I got for $175 new and I really don't want to spend $5000 on a relay for such a cheap freezer.

 

[MrM1]

What about something like this? Would plug into the wall and freezer plugs into it. Temp probe goes in the freezer. There are a few different brands and variations

iPower Variable Duct Inline Fan Speed Adjuster with Temperature Controller for Hydroponics Exhaust Vent Blower, 750W 6A https://a.co/d/d6kFdXQ

 

[featherlite]

I use one of these Ink Birds to control my freezer for use as a refrigerator when I have shore power. I am very happy with it.

Temperature Controller ITC-308

INKBIRD ITC-308 is out-of-the-box, safe and reliable with temperature calibration, independent setting for refrigeration and heating, over-temperature protection and automatic temperature control system for more accurate temperature control. With output power of 1,100W(110V) /2,000W(220V), it...

inkbird.com

 

[MrM1]

The one I link doesn't go low enough, try this one or the one above

BN-LINK Digital Cooling Thermostat Controller for Cooling Device Circulation Box Fans 40-108F 8.3A 1000W https://a.co/d/g3aojh0

 

[42OhmsPA]

I've been using this since 2017 to control a secondary blower on my coal stove with the probe in the plenum(coal on a solar forum, I know crazy ?). Plenum hits x temp it turns the blower on to pull air off the stove, when it hits low temp setpoint it shuts the blower off.

You could use it the same way for a fridgeezer, just set your temps accordingly.

WILLHI WH1436A 10A Temperature Controller 110V Digital Thermostat Switch Sous Vide Controller NTC 10K Sensor Improved Version https://a.co/d/gj536cb

 

[Bluedog225]

I read somewhere that running a freezer at fridge temps was hard in the equipment to the point of failure.

 

[E. Cho]

I also use the Ink Bird lined above, now going on 2 years and it has been great, but it does use 110-120V power, so I run my inverter 24/7 which only uses 16 watts. The Inkbird uses very little power and the chest freezer after start surge only uses 50 watts. With the Inkbird, I set the High Temp at 5C and the Low Temp at 2C and the low cost 7.2 cu ft Danby chest freezer I use cycles between the two temperatures and sips energy.

The other option is a 100% mechanical controller made by Johnson Controllers. It does not require power but it can be expensive and difficult to find and maybe not as fine to dial in for temperature control as the digital Inkbird. But it used to be extremely popular for off grid use. I'd consider it if I could find one for a low cost.

FWIW, I have read a lot on the topic over time and not once have I EVER seen information about running a freezer as a fridge as being hard on the equipment to the point of failure. As well, I emailed the manufacturer on this topic and how to finely dial the stock thermostat and the technician did not warn me against it, only that the stock thermostat could not have fine enough control. I got it within a 10C degree swing, but either just under 0C or up to +10C before I gave up and just bought the Inkbird. The Johnson Control model was over $100 plus shipping and I didn't want to spend that much in case the freezer to fridge didn't work for my needs.

Also, Danby had recently announced a chest Freezer Fridge combination unit that has a thermostat that can be adjusted for either use. I've never looked at the specs to see how technically it might be different than a specific chest freezer or compare their energy use. The cost was about $600 CDN whereas I paid $249 CDN for mine.

Depending on the humidity in your area, chest freezers do not have auto fan defrost, so they can have some or a lot of moisture build up, but should be no problem for short periods in a humid area. My humidity is low, so I only need to remove water with a sponge every few weeks.

 

[SamDeleted]

Simply turn the freezer up full and control the AC input with an external digital thermostat as linked above ... It's well worth it, externals are much more accurate than the built ins

Get one that has a delay feature or that can offer separate cut in/out temperatures , these digitals are so accurate they can end up turning your freezer on and off 10 times a minute which isn't good for the motor , so if you can let it swing between say 40f & 37f that'll work better


47f & 37f are the absolute outliers temps your fridge should reach



EDIT: I didn't read your post properly lol, thought you were just trying to control a freezer better, not use it as a fridge ..., but this is still interesting:





Another thing you can do with a freezer is stick it on a timer (after the thermostat) and turn if off for 6/8hrs over night, have it turn back on during solar hours so it's not hitting your batteries over night, it'll draw hard when turned back on but if you've got excess solar in the day that's not an issue


If you do want to play the 'turn it off overnight game' , you'll need a separate digital thermometer with max/min & an external probe to keep an eye on the temperature inside , adjust length of time turned off accordingly

Freezers want to stay within 6f to -2f roughly

Put both probe cables inside the fridge, shut the lid on them


Better prices are available:
Digital thermometer (max/min)

Hope that makes sense sorry for the essay

 

[SamDeleted]

.

 

[SamDeleted]

I use one of these Ink Birds to control my freezer for use as a refrigerator when I have shore power. I am very happy with it.

Temperature Controller ITC-308

INKBIRD ITC-308 is out-of-the-box, safe and reliable with temperature calibration, independent setting for refrigeration and heating, over-temperature protection and automatic temperature control system for more accurate temperature control. With output power of 1,100W(110V) /2,000W(220V), it...

inkbird.com

Thats very similar to the one I use, works perfectly

 

[HarryN]

Look at digikey for electronic thermostats.

It might surprise you that those old fashion analog thermostats that we like to scoff at are remarkably good at temperature control, especially for the range that you are looking at.

The electronic ones tend to be +/- 3 - 5 F.

The very large heat of fusion of water can really help with temperature stabilization.

2 weeks - for a moment I was imagining burning man.

 

[SamDeleted]

https://www.hunker.com/13409719/can-you-use-an-upright-freezer-as-a-refrigerator

 

[Bluedog225]

Fwiw generally and post no 7.

May not be relevant to your use case.

Rack battery storage-upright freezer

I’ve given way too much thought to how to keep my SOK rack batteries cool in Texas. Underground, insulated box, water cooled, mini split, etc. As far as I can tell, this is the direction I’m headed. Took a bit of digging to find a wire shelf (not cantelever) upright with 100 lb per shelf...

diysolarforum.com

 

[Rednecktek]

InkBird on the way, thanks all!

 

[rodrick]

InkBird on the way, thanks all!

Costco also sells the 7cuft media convertible chest freezer/frig for 269.99 they were only 169.99 a year ago but even at the 269.99 still a good deal I’ve been running one for five years now freezer version only no problems at all and having a spare in case of a failure was cheep at the old price I ended up buying 4 2 freezer’s only and 2 convertible and have been very pleased something to consider if you haven’t got the chest yet

 

[JJJJ]

This is a topic discussed in other circles. Basically switch out the freezer thermostat for a refrigerator thermostat. There are plenty of web sites that discuss this. I did see the InkBird on Amazon and it looks like it is on the way.

 

[E. Cho]

I did not find switching the freezer thermostat for a fridge thermostat to be a good solution. Finding parts was not easy here and then there was the main problem of removing the freezer thermo coupler and the difficulty of routing in the replacement refrigerator unit. That can be a real PITA to pull out and replace and it can cause damage to the insulation or interior material and or greatly reduce the accuracy of the refrigerator thermo coupler, if it cannot be re-routed into the correct position. Then trying several or more times to find the correct spot could further damage the insulation with each push or pull. I opted against it when I got to the point of pulling the freezer thermo sensor out as a possible option.

The InkBird digital thermo sensor is so incredibly easy, very accurate and causes zero problems or physical damage and the chest freezer can be returned to stock in an instant.

The InkBird was also similar in price as a refrigerator thermostat that "might" have worked (am not in the USA) but the InkBird would be one hell of a lot easier, more accurate, more elegant and removeable without damage.

 

[JJJJ]

The InkBird digital thermo sensor is so incredibly easy, very accurate and causes zero problems or visible damage and the chest freezer can be returned to stock in an instant

These are great selling points. Definitely a lot of improvement since I looked at this last.

 

[Rednecktek]

Installed the Ink Bird today, worked like a charm. Thanks y'all!

 

[Nobodybusiness]

So I had this BRILLIANT thought that if I got a chest freezer and just set the thermostat to 1 that it would hover right around the freezing mark....

Yeah, not so much... BUT having seen videos of people doing it I know there is some sort of magic relay/thermostat/probe/thingymabober out there that will go between the freezer's compressor/thermostat system and the wall to have it kick on and off at fridge temperatures.

Unfortunately I don't know the terminology involved to even start looking for that magic thermostat/contactor box.

I'm good keeping it all 110v so no inverters or low/high voltage combinations or anything, I just don't know what I'm looking for or what makes one better or worse?

Someone on here knows what I'm talking about, right? Wanna point a guy in the right direction?

Some maybe important details: It draws between 62-74 watts and only gets used 2 weeks a year at the family camping trip. It's a 7cf Magic Chef that I got for $175 new and I really don't want to spend $5000 on a relay for such a cheap freezer.

Never even knew this was possible.

Great thread and information!!