My First Cave

[rsterne]

My wife and I have started into this adventure, and since we recently closed our small Motel we had some bar fridges, so I converted one to a Cheese Cave....



I got an external temperature control and humidity sensor, and removed the door on the freezer compartment (since taking the above photo), to prevent it icing up.... I partially blocked the dehumidifer vent, placed three trays of water in the bottom, and I have achieved the following performance profile.... The humidity dips while the fan in the fridge is running to 55%, but recovers quite quickly to 65%, then more slowly.... reaching 88% before the fridge turns on again....



The fridge runs for 17 minutes and cycles about every 2 hrs. 10 min. and produces an average temperature of 54.4 *F and average humidity of 76.5%.... I'm quite pleased with this, but only time will tell how well it works....

Bob

[Jeannie]

Thank you for such detailed data.  Keeping my cheese cave stable is always a challenge.  I will try some of the things you mentioned.

[rsterne]

It would be great if the Humidity was as stable as the Temperature (3 deg. range), but the average of 76.5% is not that bad, and it is only below 65% for about 17 min. of the cycle (about 13% of the time).... It spends a hour at over 80% (46% of the cycle time).... We have a lot of surface area of water, which I think is what keeps the humidity high and allows it to recover quickly....

Removing the freezer compartment door aided in reducing the dip in humidity when the fan is on, but the biggest thing that it did was to keep frost from forming on the metal floor and walls of the freezer compartment, which led to dripping ice water into the ice tray, causing it to create condensation and drip on the cheese.... That no longer happens with the freezer door removed....

I may be wrong in my approach, but we are concentrating on hard (and semi-hard) cheeses, so I plan to just find out which ones work well in the cave conditions we have....

Bob

[MacGruff]

I have the same controller you have, but a slightly large refrigerator that it controls.

To solve the humidity issue I purchased a small room humidifier and stuck it in the fridge, snaked the power cord out of the fridge and plugged it in to the controller. This way the controller turns the power on when the humidity drops below the range I want and I am seeing a consistent range of 87% to 95% (what I set it to).

The three "tricks", if you will are:
1.   Get a small enough humidifier to fit your space (and you lose cheese space, of course!  :-(  )
2.   Make sure you get one that can be left on all the time. The first one I purchased had a button you needed to press to turn on in addition to power, so that did not work. The one I have now does not.
3.   Check the water level every so often.

[rsterne]

Thanks, I will keep my eye out for a small humidifier.... I have hear of the "Cave Cube", but I guess it is no longer available?....

Bob

[John@PC]

.... I have hear of the "Cave Cube", but I guess it is no longer available?....

We used to make and sell the Cave Cube humidifiers but discontinued about three years ago when we suspended our cheese making equipment business.  We also sold ultrasonic mist makers for larger cheese caves and did some experiments with ultrasonic humifiders in fridge-sized caves.  I was never happy with the mist humidifiers in a small enclosure because of condensation unless you had a circulation fan to distribute and vaporize the mist particulates.  The Cave Cube was a very simple design using a evaporation wick with 12v circulation fan.  I have put together a DIY version of it that I want to post when I get some time.  The other option as you probably are aware are separate ripening boxes that eliminate the need for added humidification but take up valuable space in a small fridge like yours.  Since you have a %RH controller already you could go the vaporizer / humidifier route and hit your target much better than with the pans.  Whatever you put in the fridge just make sure it's low voltage for safety sake.

[rsterne]

I have ordered an ultrasonic mister, and have the perfect size box (with lid) to put it and its water supply inside.... I am going to try offsetting the mister and the outlet hole, and will add a small USB fan if necessary....

Bob

[John@PC]

Sounds like a good plan.  There are a bunch of low-priced USB fans available if you need one.  Let us know how it works out.

[rsterne]

OK, so I got the mister installed in one corner of a water box, with lots of holes in the opposite corner for the fine mist to escape.... It works great, lots of mist coming out but no larger water drops (they hit the lid and drop back into the reservoir).... The problem is that it works worse than just the simple water tubs.... I can get the humidity to about 88% with the tubs (lots of surface area) but with the mister by itself it won't go about about 70%.... Even putting most of the tubs back inside it won't go over about 75%.... Even stranger, if I unplug the mister, and change nothing else, it goes back to working fine.... 

So, it looks like I wasted the money on the mister.... If anyone has any idea WHY this is happening, please post it here.... I can't see why adding a mister is reducing the humidity.... 

Bob

[rsterne]

I gave up on the mister and removed it and I'm back to simple water trays to provide the humidity.... I did, however, restrict the fan outlet to about 30% of its original area, and that made a big difference to the drop in humidity when the fridge is running.... The fridge is running for about 15 minutes out of each 2 hour cycle.... Here is the new performance graph....



Instead of dipping to 56% RH at the end of the fridge cycle, it only drops to 72%, which raises the average humidity to 83%, from 76% before.... That puts me in the middle of the range I want, and as the number of cheeses in the cave increases, if the humidity increases too much, I can just remove water trays to compensate.... I think I now have a dependable arrangement for aging my cheese, at least I hope so....

Bob

[John@PC]

... but with the mister by itself it won't go about about 70%.... Even putting most of the tubs back inside it won't go over about 75%.... Even stranger, if I unplug the mister, and change nothing else, it goes back to working fine.... 

That is strange, esp. your second observation.  Are you using the USB fan and your controller? The mist has to be going somewhere: either vaporizing, condensing and/or freezing on the coldest surfaces.  Do you have the USB fan on when you're using the trays?

[rsterne]

I had no luck with the mister, so I never purchased a USB fan to try it (good money after bad?).... The freezer door is taped open and does not freeze (only a slight frost just at the end of each compressor cycle), and there is no collection of condensation I can find from the mister.... The only thing I can think of is that the rise in water temperature caused by the ultrasonics (they mention that in the instructions) is somehow affecting the humidity.... Perhaps that heat source (the mister draws 16W) inside the fridge is causing the compressor to cycle longer, and depressing the humidity further, but that does not explain the slow humidity rise after the dip.... I gave up on the mister as a result, and am happy with my new results obtained by restricting the airflow from the fridge fan....

Bob

[John@PC]

Perhaps that heat source (the mister draws 16W) inside the fridge is causing the compressor to cycle longer, and depressing the humidity further, but that does not explain the slow humidity rise after the dip....

That makes sense.  Also as the water in the mister cools in the fridge you will get less "mist".  If you had the fan I was going to suggest that you use it with the pans to increase rate of vaporization but it looks like you're in a pretty good zone now.  If you did want to bump it up without a fan you can purchase humidifier wicks and stand them up in your water pan.   Here are the ones we used for our Cave Cubes.  They increase wet surface area quite a bit and last a long time.