Dry Cure Cabinet

[mjdeez]

Heres a graph of my temps and humidity from my data logger

Are you controlling the humidity via a humidifier and / or extraction fan with humidity controller? Or just letting the humidity lie where it may as the temperature swings up and down?

I got my frost free freezer a couple of weeks ago, and a guy at work gave me a couple of really heavy duty relays that he didn't need anymore. I'm pretty excited to get started on this project.

[mikeradio]

Sorry I missed your question.

I am using this humidity controller  http://www.sausagemaker.com/19013humiditycontroller.aspx
It has one plug for humidity which I have a ultrasonic cool mist humidifier and one plug for dehumidify
which I have a small dehumidifier plugged into.  One thing I don't like is there is no differential, either the humidifier
is on or the dehumidifier is on, there is no time when both are off.

Everytime the compressor runs the humidity drops, then climbs back up after it turns off.
I have been using about 1 gal of water in 2 weeks in the humdifier and only dumping about
a quart out of the dehumidifier.

I am looking for a better controller if anyone has any suggestions.

[mjdeez]

Sorry I missed your question.

I am using this humidity controller  http://www.sausagemaker.com/19013humiditycontroller.aspx
It has one plug for humidity which I have a ultrasonic cool mist humidifier and one plug for dehumidify
which I have a small dehumidifier plugged into.  One thing I don't like is there is no differential, either the humidifier
is on or the dehumidifier is on, there is no time when both are off.

Everytime the compressor runs the humidity drops, then climbs back up after it turns off.
I have been using about 1 gal of water in 2 weeks in the humdifier and only dumping about
a quart out of the dehumidifier.

I am looking for a better controller if anyone has any suggestions.

Thanks for getting back to me.  I bought a perfect size frost free freezer also, and this was my worry as well... the compressor running forcing dry air into the chamber.  I plan on building my own temperature and humidity controllers. It will take awhile so I don't plan to have results anytime soon. But your data is REALLY helpful because now i know what i'm up against.

For your setup, i see you have the dial set to around 65% humidity. It looks like the humidifier is turning on at 70% and off at 90% (maybe earlier, hard to tell). Much wider band than the advertised 7%, but this could be due to the distance between the humidifier and sensor / controller -- hard to say. It's unfortunate that you can't decrease the 7% band to something like 2%.  Do you have a circulation fan to get the humidity uniform?

One thing that struck me about your humidity is how high the gain is... the slope is pretty steep in both directions. From what i can gather, the humidifier is on during the steep slope up, then dehumidifier turns on and the humidity levels off, then the humidity spikes down when the fridge kicks in.  Another way to look at it: At least your humidifier is perfectly balancing out your fridge dehumidification .

I had a couple of half baked ideas for you but the more I think about them the more holes see. 1. Limit the gain of the humidifier with a 555 timer circuit + relay to lower the duty cycle -- would be stable but probably wouldn't buy you much more accuracy.  2. Add a 2nd humidifier to turn on only when the fridge is on. May be unstable and not necessarily better. At least now your average humidity is controllable. Also your dehumidifier isn't doing much so counteracting the fridge's dehumidification may not be a good idea.

Another note: Keep in mind your dehumidifier may be kicking out heat, increasing temp, kicking on fridge and dehumidifying via fridge. Maybe cut down on any heat you have in there (lower wattage bulb, unplug de-humidifier temporarily). This would reduce the turn-on cycles of the fridge, dehumidifying (via fridge) less frequently. Then you would have an occasional down spike but the humidity would mostly at the top end (which you could lower with the dial).   This is a lot of speculation here, but I hope it helps you get it figured out.

Control theory aside, what kind of cheese is that?

[mikeradio]

Thanks  mjdeez

The cheese is an English Cheddar call Lancashire, my first cheese I made, it has to age 6 to 8 weeks.

I don't want to steal this thread so I move to a new one.  I will try unplugging the dehumidifier and plot the results
and post them in a new thread, that's a great idea.  There is a fan that runs continues you can just see the
fan guard to the right of the cheese.  The cold coils are in a chamber in the middle the bottom is open and draws the air
up through the coils and out.  I also installed 300w of heat inside the chamber for the winter months because it
is in an unheated garage.  I will post more pics and plots soon.

Mike

[carnie1]

Well ya got all the ingredients, but I'll be on the road in May, maybe an adult beverage and some jerky will convince me to do it right away, I'll check it out when I bring that test item over

[mjdeez]

Thanks  mjdeez

The cheese is an English Cheddar call Lancashire, my first cheese I made, it has to age 6 to 8 weeks.

I don't want to steal this thread so I move to a new one.  I will try unplugging the dehumidifier and plot the results
and post them in a new thread, that's a great idea.  There is a fan that runs continues you can just see the
fan guard to the right of the cheese.  The cold coils are in a chamber in the middle the bottom is open and draws the air
up through the coils and out.  I also installed 300w of heat inside the chamber for the winter months because it
is in an unheated garage.  I will post more pics and plots soon.

Mike

The cheese sounds good.

Try unplugging the heater too. If the ambient temperature is below your set point, use a much lower wattage instead. 50 to 100W.  This is probably giving off much more heat than your dehumidifier, but you can check the specs on that dehumidifier. Its probably on a sticker or something.

I'll catch you in the new thread.