Humidity issue in my first chamber

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wasuky
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Humidity issue in my first chamber

Post by wasuky » Fri Nov 27, 2020 21:30

Hi guys! I am a bit embarrased because I have read posts about this several times but still can't figure it out.

So after a month trying to figure out how to program an arduino board (I know my thing of electronic but have no clue in software development) I was finally able to crank the thing up. What I made was basically a Wifi controller. It was supposed to control temperature and humidity but since the fridge temperature is almost all day between 12-15 ºC I decided to use it to control just the humidity. So I basically send the sensor reading to a web service which sends it to an app that allows me to watch what the sensor is reading and change the min/max humidity parameters.

I am using no-frost old freezer/fridge. One side freezer and fridge on the other side.
Neverga ge.jpg
I took out everything from the fridge side to make some room and monitor it for a few days with a STC-3028 controller. The controller read 13ºC and 74% average and of course I fell in love. I went to the kitchen and made a 1kg spanish chorizo in a 55 casing. After 1 week the thing had lost 20% (seemed odd to me) and in 2 weeks it lost 38% (then I knew there was something wrong). I cut it open and of course it was casing hardened. I put the sensor in a closed plastic bottle with wet salt and after 12hrs it was reading 92%. So the damn thing was reading 74% when it was actually around 55%. I know... my bad, I trusted the "calibrated" stamp (thank you China).

Anyway I now have this arduino board set up and running. I also made a humidifier with a mist maker used in holloween bowls and a computer fan that pushes down the fog and forces it to go out through a pipe.

I can make the humidity go up to 85% but it goes down in matter of minutes. I been playing with the min/max humidity control but what I get to turn on/off the humidifier every 3 to 5min.

This is how my screen looks like (the temperature chart is above and cannot be seen in the picture). As you can see my min humidity is 71 and the max is 79. So it gets to 69-70% and it starts going up to 80-81%. It takes 5min to go up and 5 more to go down which makes the relay click every 5min. I don't like this setup because it gets too low.
01.jpg
This is the same chart for the past 12hrs and the same one from the last hour.
2.jpg
3.jpg
Now if I try to keep the humidity between 75% and 80% I have to set the minimum in 76% and the maximum in 79%. With this setup the humidity goes down to 74-75% in 3min and goes up to 80-81% and 3 more minutes.

I have no idea how often the humidifier should go on/off in a "normal" curing chamber (though I know curing chambers should have a dehumidifier). Could it be normal for the humidifier to go on/off every 3min?
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Bob K
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Re: Humidity issue in my first chamber

Post by Bob K » Sun Nov 29, 2020 15:44

How often does the refrigerator fan run.
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wasuky
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Re: Humidity issue in my first chamber

Post by wasuky » Sun Nov 29, 2020 16:42

The fan located in the freezer side and it runs almost all day. The fridge timer stops the motor and the fan every 6hrs for 15-20min.

Early this morning I stopped the motor and the humidity started going up until 75-80% and it stayed that way for 20-25min so I decided it was time to add the temperature controller to the board.

Right now I am adding a piece of code to the arduino board to control the temperature (I thought it wouldn't be necessary). Still don't know if I am just going to turn off just the motor (this setup will keep the fan running until the timer tells it to stop) or the entire fridge (it is the easier thing to do and I belive it's what everybody does). I am also adding a piece to update the code throught the wifi connection as it's just not cool to connect/disconnect every time I decide it's time for an update.
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Re: Humidity issue in my first chamber

Post by Bob K » Sun Nov 29, 2020 17:09

Ok. The fan running also works as a dehumidifier. Use the temp controller to shut down the whole unit. That should smooth out your on/off curve for the humidifier. Once you add product to the chamber the humidifier will seldom run as the product adds moisture to the chamber, The refridge fan running all the time also contributed to the dry rim in the first batch.

Here is a nice setup with a side by side: viewtopic.php?f=25&t=8198
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