I needeed a good digital fridge thermostat.

[Seriously Slow]

Originally Posted by wingssail

I looked at several of these and most I saw required AC electricity, which I was not prepared to supply. So I stayed with the standard Dometic thermostat which seems to work pretty good, although it does not have a cool digital display.

The ones I used were labeled for 12v AC but I found that they also worked on 12v DC and have for 4 years. I read it from some other user but can't remember where.

[Hermia II]

Have a look at www.egismobile.com Fridge Optimizer (only DC, 12 and 24v) for a very advanced and efficient unit. Probably the best there is.

[David B]

Originally Posted by Olly75

I have two, one for the fridge and one for the freezer. They are great units, dramatically reduced energy consumption and so far had no issues with them in 2 years. Bear in mind that they come as a stand alone unit, so I got a project box on ebay to fit them into.

Wondering about the energy consumption reduction.
Can you advise a rough percentage, and why?

Thanks,

David

[Hoohaa]

Originally Posted by David B

Wondering about the energy consumption reduction.
Can you advise a rough percentage, and why?

Thanks,

David

They cycle the fridge or freezer off and take the guesswork out of the temperature control with the results that your fridge and freezer only run as required which is generally allot less than Just switching them on full until the beer starts to freeze.

[Olly75]

Originally Posted by David B

Wondering about the energy consumption reduction.
Can you advise a rough percentage, and why?

Thanks,

David

I dont have exact numbers as I dont have an energy monitor, but the fridge cycled probably 20% less than with the standard issue thermostat that came with the unit. Suspect its down to the precision of the digital thermostat and the sender itself, the ability to control what temp that the compressor turns on, and how cold it will make the fridge and finally you can set a a time between cycles.


Definetly one of the cheaper and better upgrades Ive made to the boat.

Edit, what Hoohaa said!

[Hermia II]

Originally Posted by Hermia II

Have a look at www.egismobile.com Fridge Optimizer (only DC, 12 and 24v) for a very advanced and efficient unit. Probably the best there is.

There are AC units as well https://www.egismobile.com/shop?search=fridge

[tangara]

I purchase Geekcreit® W3230 DC 12V / AC110V-220V 20A LED Digital Temperature Controller Thermostat Thermometer Temperature Control Switch Sensor Meter
US$5.49 thermostat on Bangood and are very satisfied at this price you order 2 and you have one for spare.

[David B]

Originally Posted by Hoohaa

They cycle the fridge or freezer off and take the guesswork out of the temperature control with the results that your fridge and freezer only run as required which is generally allot less than Just switching them on full until the beer starts to freeze.

Thanks - I was wondering whether more accurate temperature was all there was to it, or whether a tighter hysteresis was a factor.

[David B]

Originally Posted by Olly75

I dont have exact numbers as I dont have an energy monitor, but the fridge cycled probably 20% less than with the standard issue thermostat that came with the unit. Suspect its down to the precision of the digital thermostat and the sender itself, the ability to control what temp that the compressor turns on, and how cold it will make the fridge and finally you can set a a time between cycles.


Definetly one of the cheaper and better upgrades Ive made to the boat.

Edit, what Hoohaa said!

OK - so I suspect then it is the tighter hysteresis that you get with an electronic control. Makes sense. Rather than a swing of a degree or three, it controls closer around the set temp, so there is no pull-down factor. It's a while since I had to play with this sort of controller, but from memory, you can set the hysteresis also (lower level in the menu system.

So I did have on my list, a set of three digital displays for our refrigeration systems - that's changing to controllers now! Just have to hone in on the model with hysteresis control, because tuning that could be a significant factor also - cutting in too often and you get the in-rush current factor. Not enough and you get the pull-down factor. Hmm - a DC power meter (period not instantaneous) would be useful for the tuning ……..

Thanks for the ideas (and the addition to the list ……..)

[David B]

So does anyone know of a source of controllers in this form-factor that have adjustable hysteresis?

[Matt Johnson]

The unit shown in the first post is fully adjustable for the on/off temperature swing. You can also set a delay or limit to how often it cycles.

Matt

Originally Posted by David B

So does anyone know of a source of controllers in this form-factor that have adjustable hysteresis?

[Hoohaa]

Update. I have two of the STC 1000 on there way.
Thanks for the replies.

[David B]

Originally Posted by funjohnson

The unit shown in the first post is fully adjustable for the on/off temperature swing. You can also set a delay or limit to how often it cycles.

Matt

Perfect - thank you! I think I will order four of them (one spare). Just need to design a panel for them now …...

[Gerrycooper56]

I installed exactly the same things for my fridge and freezer. Been operating since October last year without a problem. Mine are wired through a refrigerant solenoid valve and then to the compressor run solenoid. (One compressor but split lines)

[Cuvee]

I've been using the AcuRite wireless digital fridge and freezer thermometer for the past 5 years to monitor fridge and freezer temperatures. Each sensor runs on 2 x AA batteries (preferably lithium). Their current model 515M retails for only US$35.