That’s not looking ‘bad’ to me. Especially for a shed.
If you want to even out the temperature swings further then you are looking at insulation and thermal mass. If you are not familiar, a good reference book is Designing and Building a Solar House by Watson.
Cheers
G
This is a book I downloaded a while ago that looked awesome but I haven’t read yet:
https://www.amazon.com/Golden-Thread-Years-Architecture-Technology/dp/0442240058
My friend who works in solar recommended this one to me for practical use:
That Golden Thread book is pretty neat @Dirt_Wizard!
@Gpaw for sure, it’s not ‘bad’ but I’d like better. Insulating the shed is not really a viable option, although I have considered a larger water cooler. Twice the water, half the deviation, all else the same. It’s a balance of what I’m willing to do and spend money on vs. what I’m not. Insulating the shed…probably not. Finding a bigger water cooler, depends. It’s not necessarily rational either. Appreciate the suggestions though. Hopefully in a year or two I’ll be buying a bigger house, with room to do all this stuff properly. Room for a real tent even 
I got about 1.5 dry pounds from my first cycle this season, figured I’d post an updated plot.
When I changed to RH control mode last week the humidity stabilized significantly for “cure.”
The large pertebations after that were caused by me opening the cabinet to trim or starting another dry cycle yesterday afternoon. It is very good at humidity control. Temperature, well, it’s not as good as I’d like but my external conditions play a huge part in that. It’s getting down in the 40s and up to the 90s in the shed.
My big NLD Panama x Malawi won’t be done for a few weeks and I’ll be operating in a different regime - heating mostly. I got a 500W digital aquarium heater I’ll be placing in the water cooler - I computed that the losses will be on the order of 200W so the 500W should be adequate.
Results?
Average temp was 64.5F, average RH was 63%, and the average VPD was about 0.76kPa. Very similar to what I ran last season with my VPD control technique. And it worked well. I don’t grow frost-monster varieties I’m more into heirlooms, terps and effects.
I’m very happy with the terps and bud consistency this season. Ran Indiana Bubblegum from FDM and 907 Blue Genes from AKBB. Bubblegum is on the left, and 907 on the right.
I recently looked at cryo cure. I’m considering freezing test sample to 0 degrees F(standard freezer temp.), then putting in a slightly greater vacuum then that required for sublimation, and slightly adjust vacuum as I allow it to thaw. Just experimenting with a friend who lives in Oregon. I got a square 2 gal vacuum chamber to play with next year, my curiosity with his produce. I might need a set-up for small mason jars, for multiple tests. The device looks like a clothes dryer with a vacuum sealed door, that stops short of complete freeze drying, it seems to me like frozen produce is put in it with some type of radiant heating surrounding the racks in a vacuum. The displayed products don’t have the shrinkage normally expected. Limiting the frozen sublimation time is how they don’t over dry, that is the trial and error. the chamber around the racks might spin to encourage the frost of the sublimation outwards to where it is channeled to a chiller? to be collected. For my experiments I’ll try having the sample positioned in the center of the jar, away from frost build-up. I only recently heard of vapor pressure deficit, then the cannatrol, then this cryo cure, my curiosity with this makes me wish I lived in a FREE country.
I’d be interested to hear how it goes. I had wondered how the freeze drying works for several reasons. I saw it advertised when I started reading some of the cannabis magazines. Our local Tractor Supply store has a home freeze dryer that I took a quick look at, it’s becoming a more accessible technology. I’ve been buying freeze-dried shallots and garlic at the local farmers market processed by one of those machines. Maybe I should chat with one of them and see if they are cannabis friendly and would be open to helping play with drying some weed.
What I wasn’t clear on, and still am not, is how they regulate end-state moisture content. I’m intrigued though. It sounds like they just do a specific interval, or perhaps they monitor the extracted water quantity. I’d think it would be possible to do that if they chill a collection plate (to encourage deposition) in the vacuum chamber. If you enter the start weight you could probably get a result pretty close just measuring the extracted water.
Maybe I’ll play with it myself next year. I have access to vacuum pumps and chambers that I could use. Perhaps we should start a thread dedicated to posting experiments using vacuum/sublimation methodology.
Please let me know if you do any experiments, I’m very interested 
In my limited XP with cold temps and drying it halts any cure process. I placed 4 oz in the fridge after the flower had dried enough to place in Grove bags. Cure was halted.
I must assume that the above discussion is about the water content at the end of the dry cycle and has nothing to do with curing. 2 separate processes in most cabinets apparently.
I’ve had good success with a 14 day hang in 60f and 60%humidity trim and seal in vacuum bags . Then I’ll freeze it or store in a cool dark place to cure .
I haven’t noticed that it kills the cure possibly the cool room vs the freezer the terps may be a bit better not froze but the difference is minimal.
2 year old weed done this way still has a great smell and taste trick is if you over dry it your screwed.
I read today about rapid freezing causes the ice flakes to be smaller, less disruptive to what’s frozen. Max Montrose of trichomeinstitute.com had a video today, called stinktank about abstracttech.com and how the stronger the smell the more potent. Trichome has an interesting blog section also. The -40 degree freezer will get use from quickly freezing the prime ribs on sale around Thanksgiving and Christmas, that I slice up for steaks. Also learned to dip fish in ice water before wrapping and putting into quick freeze at -20 or so, the layer of water helps keep’em fresh. Thanks for your info. and starting a thread idea. I went to tractor supply website, those harvest right freeze dryers look like the small cryocure and are $2700 to 5,000.
Doing some google searching on lyophilization(freeze drying) I came upon a diagram showing a small separation at different temps for vapor pressure above ice vs. water at -50 C to 0. Don’t know if that matters much. It seems the plates the product is on, is heated slightly(not enough to melt the ice) to increase the rate of sublimation, and the nearby condenser which is colder than the product collects the vapor as ice, this is called primary drying. Secondary drying is evaporation from heat. The times for both seems to be figured from trial and error(one study said just that), and the amount of time for each is crucial in importance. Key parameters are product temp, shelf surface temp, and the vacuum. I’d advise building/buying what size shelves you plan or hope for, then experiment with different times. The moisture content question I can’t answer.
Something like this one? Good lead @obiewanna1 I had not seen this diagram and it makes so much sense
Diagram scraped from here:
This dude seems like the guy to read about building your own, he’s a high vacuum engineer who does training and consulting on this specific thing among other manufacturing techniques using vacuum, check out his site!
Here’s someone’s home engineered project from almost a decade ago with some really detailed process notes and feedback, they have this chart leading off the article which I have to look at and try to understand:
People tell me freezing is ok but my brain can’t quite get around it, I keep my storage dorm fridge at 40-45F so there’s still a slow cure happening, and I like to bring the bud moisture back up from 58% RH to like 62-64 for the freezer because I think in my very unscientific experiments it keeps the cure moving better. I will eventually try freezing jars or vac sealed buds once we get a chest freezer and have the room.
Love what you have going on here… was wondering if you had considered using a peltier semiconductor to help get Temps down in the box
The chance of being able to rescue frosted produce, and doing once while improving the cure and size is what I was attracted to, I agree with the “Don’t phase change my stuff” cautionary approach. I havent grown since 05, and started assisting a friend in Oregon with his cure last year, which led to vapor pressure deficit, then cannitrol, now cryocure, I’m interested in DIY “affordable for working types” kind of substitutes for high priced stuff where I can. The $2700 freeze dryers adjusted properly via trial and error and help from the second diagram above for timing, and what we find out, and share, might help improve things. Thanks for that timing diagram, and the acknowledgement.
IIRC they’re nice for small DWC containers too. I think the one I remember was called the “Ice Probe” or something like that.
Nice job @FieldEffect!
Any updated findings/comments?
I am considering something similar but like the simplicity of Raspberry PI for implementation.
My environment will be maintained at 70F year round so that makes things a little easier.
Standard RH will vary based on season but will typically be above 49%.
Hindsight I think RPi is a better choice. Initially I figured this would be a simple thing, and the complexity evolved to push the capabilities of the Arduino Nano.
I didn’t realize that the hardware would be as challenging to assemble as it was either. I think the way to proceed would be something like a RPi, perhaps with a expansion board providing the I2C ports for sensors and power switching for control.
I think I’m going to build a new version. I want to attempt a different method of dehumidification based on two heat exchangers. One held at the desired dew point, the other, placed after the “dehumidifier” at the desired temperature, which would be 5-10 degrees warmer.
I want to achieve the ultimate in stability. Not because I think it’s necessary, but because I’m curious what the effect would be.
Overall I like the VP differential control method provided you can regulate the temperature below 65 degrees or so. If you want to achieve a stable end product to hermetically seal I’d perform a fixed absolute humidity “cure” to reach the proper moisture content before packaging. Grove bags seem to be pretty forgiving, it doesn’t matter as much.
You can take it as far as you want, but I think the original concept of a reasonably stable dry box was 75% of the way there. I’m just curious where the upper bound is now 
Yep. That’s exactly my reasoning for the RPi rec. Easier expansion. Everyone has Ras expansion.
I understand your original ideas and think they’re outstanding! Bravo!
Interesting idea with the dual dehumudification . What size chambers are you considering? Condensation is always a problem. Speaking off top of my head.
Already ordered some Grove bags. If they do what everyone says. It’s better than sliced bread…
Not sure I can offer any help in this project but am available for anything. Just ask.
Like you said…You’re 75% there already. I’d say 88% 
Way to go!
just so you know the Cannatrol Hass to be adjusted left at its default settings it produces bud that will test at 54 or 55% has a green front taste and because of its humidity level or moisture level I mean will never cure.
how on earth they can claim it produces killer bud at their settings is just beyond me they don’t know what killer bud is obviously
The way the slope is programmed 90% of the moisture is removed in the first two days no matter what you set the damn thing at. if there is a different setting for dewpoint it will get there 90% of the way in just two days.
i’ve had that thing a while now and I’ve run many many batches through it. which also means I’ve run the same exact plant through it many times at many different settings which really helped me nail down the stupid little box.
there for whatever reason is a huge difference in what the cannatrol displays as humidity level
and how the bud will test when pulled out
at their default settings running dry and cure
Machine will tell you 58 or 57% humidity level in the box at the end of day eight
I have like 60 meters , lay them all out on the table and let them stabilize next to one good expensive one I have and it’s very easy to get several meters that are dead on
they tell me the box is it 54 or 55%
Bud pulled out at this stage and put in a sealed container with a meter will read 54 or 55
The absolute fact at least in the world I live in is that once bud dips below a certain level the cure stops and no amount of rehydrating it will cause the cure to continue.
here in my environment that level is 57% if it goes below 57% and actually at 57% it starts you’ve just ruined your bud. not speculation not guessing but from running it right here in front of my own two eyes and smoking it with my own pair of lungs. smelling it feeling it touching it with my own hands
for me the Cannatrol is a way around a drying room. where I live is near impossible to drive anything properly our weather is just horrible.
The drying room was the bane of my existence oh Lord I hated to screw with it.
I basically take all canna trolls numbers and throw them out the window I run the machine with very little variance in the dewpoint for the first two days and then extend it a little for the next two days. I like to take about six days to bring the bud down to 53.5 on their gauge which gives the box an internal humidity level of 60 and when the bud comes out four days later it will test about 60 and the difference is night and day.
people who use the Cannatrol at the fault settings are ruining their bud and I can’t believe no one else but me will say it
I always call everything the way I see it. what it tells me is the people getting their hands on the Cannatrol are not expert growers nor really into the bud they couldn’t possibly be war after their first run with it they would’ve been horrified.
with all that said the little bitch box is perfectly sealed completely quiet Barranco simple yeah Barranco you stupid ass phone I wanna Barranco…Ronco simple ! with the proper settings it produces beautiful bud I’m still experimenting but I think the batch I have in right now is going to be dead ass perfect.
so the little thing will do exactly what I want with some tweaking and you’d have to fight me to take it. in my opinion it’s paid for itself many many times already and that’s just in peace of mind and saving my time and sanity.
it’s really cool all that you’re doing here and I understand why you were doing it I’m wondering if you could shed some light on the predicament with the Cannatrol
why would it tell me it’s at 60% but bud test at 54??? I guess the only explanation is is just using a chart to create these numbers on its screen it’s supposed to be at 68° and it’s supposed to be at 52 dewpoint so it must must must be at 60% humidity. Well guess what Cantral it ain’t
