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Cold thermostat and temperature recorder. Answered

Cold thermostat and temperature recorder.

Good day everyone!
I luckly obtained for free a freezer with a broken thermostat. I am planning to brew some lager beer, so I would like to replace the thermostat with a digital one, in order to set the temperature on 4°C / 39,2°F / 277,15K (ahah) (lager beer brewing temperature!) and to record it during the fermenting process, transfering then the data on my computer.

Before I get lost through the universe of electronics, could anyone of you give me a good advice on where to look? I suppose an Arduino could do the trick, but I know almost nothing about it; so i ask you.

Otherwise, I scavenged a "working", non-digital fridge thermostat, but I've just seen that it makes the freezer to get no warmer than -10°C: does anyone know if it is fixable and how to?

Many thanks for the attention, and have a good day!

Discussions

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steveastrouk

2 years ago

If you can handle the coding, then you can get 1/16th DIN temperature controllers with RS485 outputs, which you can interrogate either with standard serial protocols, or MODBUS.

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FrancescoC12Quadrifoglio

Answer 2 years ago

Hi :) It seems what I was looking for, but at first glance (very quick glance, since I'm going to bed), I didn't see the way to record the temperature. If I'm wrong, I'll see tomorrow. Anyway, thanks!

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Josehf Murchison

2 years ago

Yes get a fridge thermostat not a combo fridge freezer thermostat, or a refer truck thermostat they come in digital.

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Downunder35m

2 years ago

Most combi devices only use a single compressor and a single circuit for the refrigerant.
The freezer get's colder as it has more cooling pipe than the fridge (compared to actual inside volume).
Some modern models only cool the freezer department and the fridge is cooled by a fan drawing cold air from the freezer into the fridge.
In most cases you will only have temp control for the fridge and the freezer only has a knob from low to max cooling.
Works like this:
On min cooling the compressor only kicks in when required to lower the fridge temp.
On medium and high settings the compressor runs more often to cool the freezer but the fridge temp is only regulated through the fan.
If the fridge has the cooling pipes somewhere, than usually only in the area for the meat (top) but the regulation of temp is done the same way just without the fan.
If you check on the right you will find a lot of projects for your purpose to start.
In case you skills are low you can also use a temp controller and a weather station.
Place the sender unit in the fridge and the receiver wherever you like.
Be aware though that some weather stations with computer access can be quite costly.

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rickharris

2 years ago

Freezer temp is normally around -17 deg C to perhaps -20 deg C

If your wanting to use it as a fridge this may be problematic.

https://www.amazon.co.uk/s/ref=nb_sb_noss/256-9200...

buy one ready made could be your best option. i am not too sure what effect switching a freezer on and off so often (to keep temp high) would be.

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FrancescoC12rickharris

Answer 2 years ago

Thanks rickharris :) Anyway, buying it is the easy way, but I want to do it myself, so I will go on searching!

As they explained me, the difference between fridge and freezer should be the cryogenic gas, in quantity and quality. That is to say, it shouldn't be problematic making it switch on and off often, since the motor could be/is the same.

Moreover I think the freezer would switch on and off more often than a fridge, because the difference with the room temperature is greater in the first case and due to thermodinamics, it would be more difficult to maintain than the smaller one you would have with the fridge. However, I don't know how much does the different insulations influence all of this. So, maybe I'm wrong :P