Thermoelectric wine cooler drying and curing - DIY

We’ve been waiting for someone to make a controller. The main reason I think a lot of us haven’t tried it is the INKBIRD controller method works and doesn’t require much to set it up. All in all my second fridge I built took me 45 minutes or so.

Watch enough of the cannatrol videos and your see how they just talk in circles to sound like it’s a revolutionary concept. Using Dew point to confuse people when in reality people have been using dew point forever by controlling temp and humidity.

Creating a large dry environment is not difficult. The biggest issues the home user has is it requires a whole dedicated space in a climate controlled environment. I don’t want to dedicate a room to this. I also don’t want to waste that much electricity running a A/C, dehumidifier, fan, and a humidifier.

The lower the temperature the less chance you have for mold growth. As long as we’re controlling the sublimation process with the dehumidifier/heater we should have little chance for mold growth at the RH/Temp we provide.

most people are keeping it as cold as they can through the whole process. So 58-60F. This is to preserve terpenes. If you look at the cannatrol patents they have different priorities. Cannatrol will heat the environment up more in order to speed things up. They also have a patent that they claim they’ll heat the environment up briefly to kill mold spores. I’m guessing it’s for their larger room units but still seems very counter productive to terpene preservation.

Been using a ac infinity controller 69 pro for mine and it can do all those alerts and what nots, monitor it and change settings anyplace. can set up automation to reduce humidity I really enjoy it im on my second run through now and im happy! first run i did a little to hot and to fast got some hay second time ive slowed things down been colder and its wonderful.!

I have hacked something together with Home Assistant and a smart outlet. Inside the fridge is a wireless temp/humidity sensor.
I wired the fan from the dehumidifier to an unused 12 V connection on the power supply of the fridge. That unsures airflow and the environment is stable. The fridge is set to 14 °C or lower. This ensure the fridge is running at maximum power. If the set point is just below the actual temp it lowers its cooling (probably to minimize undershooting the set point) The dehumidifier is toggled with a smart outlet.
In Home Assistant there's an automation. If the temp is above 16 °C or rH below 60 % the dehumidifier is turned off. If the temp is below 16 °C and rH above 60 % the dehumidifier is turned on.
This ensures that the temp stays below 16 °C and the dehumidifier heats the inside, so the fridge cools and removes the water.

pahpah-cee said:

We’ve been waiting for someone to make a controller. The main reason I think a lot of us haven’t tried it is the INKBIRD controller method works and doesn’t require much to set it up. All in all my second fridge I built took me 45 minutes or so.

Watch enough of the cannatrol videos and your see how they just talk in circles to sound like it’s a revolutionary concept. Using Dew point to confuse people when in reality people have been using dew point forever by controlling temp and humidity.

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A controller could be done by someone with enough skill pretty easily. I am unfortunately not that person. Cobbling something together for personal use and something for the general public to use is 2 totally different skill levels.

All companies love to talk in circles and talk like whatever over priced thing they are selling is super complicated and cutting edge so you just buy it instead of figuring out how to make your own.

gooshpoo said:

Been using a ac infinity controller 69 pro for mine and it can do all those alerts and what nots, monitor it and change settings anyplace. can set up automation to reduce humidity I really enjoy it im on my second run through now and im happy! first run i did a little to hot and to fast got some hay second time ive slowed things down been colder and its wonderful.!

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Those things do seem to be amazing for the price. Gonna sound like an old fart but back when I started doing vpd it was pay stupid money for a controller or monitor or diy your own. So I had to learn ardunio the hard way.

Lou66 said:

I have hacked something together with Home Assistant and a smart outlet. Inside the fridge is a wireless temp/humidity sensor.
I wired the fan from the dehumidifier to an unused 12 V connection on the power supply of the fridge. That unsures airflow and the environment is stable. The fridge is set to 14 °C or lower. This ensure the fridge is running at maximum power. If the set point is just below the actual temp it lowers its cooling (probably to minimize undershooting the set point) The dehumidifier is toggled with a smart outlet.
In Home Assistant there's an automation. If the temp is above 16 °C or rH below 60 % the dehumidifier is turned off. If the temp is below 16 °C and rH above 60 % the dehumidifier is turned on.
This ensures that the temp stays below 16 °C and the dehumidifier heats the inside, so the fridge cools and removes the water.

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Very nice. I love me some smart outlets. Combine them with ThingSpeak and ifttt and one can do a ton of stuff. I've controlled just about everything in my grow with them at one time or another. Some stuff I still do cause I just been too lazy to build ardunio stuff for. As they say nothing is more permanent than a temporary fix.

beer30 said:

Very nice. I love me some smart outlets. Combine them with ThingSpeak and ifttt and one can do a ton of stuff. I've controlled just about everything in my grow with them at one time or another. Some stuff I still do cause I just been too lazy to build ardunio stuff for. As they say nothing is more permanent than a temporary fix.

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I wanted to do something with an ESP. It only needs a relay and a sensor module. Costs maybe 10 bucks in parts and an hour or two tinkering. But I have some strange bugs I need to fix before I can add more ESP to my home assistant. But this temporary situation will never be remedied.

Excited to show these results after 14 days of drying in the Koolatrol!

I started pretty high at 64 RT & 74% RH for about 1 week then dropped it down to 70% RH then down to 65% then 1% down every other day.
I learned that these parameters were pretty high for RH and think that the next time around I'll start around 70% and drop 1% every other day depending on how much water is removed and in the back tray.

This is seriously the best thread to stumble across late at night haha I didn't expect to have my tents fully packed during harvest and drying.

attached are some photos of how the process looked like at the end. No hay smell, nice and sticky bud all from this controlled fridge. I am beyond grateful for this sub and @Hook Daddy for writing this up for us DIY'ers. Wish I could share some bud with ya!

Has anyone tested to see if the cooler really does ramp up and down voltage to the peltier? Because if they are just on off thermostats like I'm guessing one could build the "cooler" bigger and possibly cheaper depending on what you have laying around the house/shop.

Edit: Found how to ramp voltage up, down, or even change them from cooling to heating. Simply put Motor controllers. So one in theory put the box in say a basement or unheated garage and it could keep the box above room temp if the room got too cold. If anyone is curious someone already made a temperature controller that can do just that. I don't know if we are allowed to link YT videos here so if not my bad.

its pretty neat , but to my understanding colder is better, if you induce heat into the box wouldnt that effect the drying?
The controller is pretty cool but it looks like it made out of all cheap chinese shit. Id like to see his controller with some nice industrial din rail equipment thats not going to fail in 3 months.

beer30 said:

Has anyone tested to see if the cooler really does ramp up and down voltage to the peltier? Because if they are just on off thermostats like I'm guessing one could build the "cooler" bigger and possibly cheaper depending on what you have laying around the house/shop.

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The Klarstein Barolo Uno has PID control. I monitored power usage during a dry cycle. That's why I recommended to set the set temp significantly below the target temp.

gooshpoo said:

its pretty neat , but to my understanding colder is better, if you induce heat into the box wouldnt that effect the drying?
The controller is pretty cool but it looks like it made out of all cheap chinese shit. Id like to see his controller with some nice industrial din rail equipment thats not going to fail in 3 months.

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The dehumidifier puts off heat inside the cooler with the current design. My thinking was one could use the heating side for if say you were using it to dry in the winter time and your garage was like 40° F it would be able to raise the temp in the box to help dry/cure.

Other use for swapping cold and hot side would be to thaw a frozen cold side a bit faster. Though it shouldn't be freezing if you regulate temp to below dew point but above freezing.

I have some ardunio stuff that is at least 4 years old now if not a bit older and it's still going. So not sure where you get the whole "fail in 3 months" crap. But yes electronics do tend to fail at the worst possible time. Good thing about the ardunio stuff is it's cheap enough to keep spares around if it's something mission critical.

Lou66 said:

The Klarstein Barolo Uno has PID control. I monitored power usage during a dry cycle. That's why I recommended to set the set temp significantly below the target temp.

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Good to know. I wasn't sure if it was something I should plan on doing if I build one or not. I'm probably gonna build something a bit bigger than the wine cooler everyone is using. I have a giant igloo cooler in the basement I am thinking about using. It's that or build from scratch with 2in foam.

beer30 said:

I have some ardunio stuff that is at least 4 years old now if not a bit older and it's still going. So not sure where you get the whole "fail in 3 months" crap. But yes electronics do tend to fail at the worst possible time. Good thing about the ardunio stuff is it's cheap enough to keep spares around if it's something mission critical.

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I wasn't referring to the Arduino and more on the Chinese motor controllers and psu its going to be cycling heating/cooling on/off/reverse etc. over and over Id just would build it with better quality relays. It would make a better system in the long run and scalability would be easier.

Could I make a suggestion its something I have been thinking about. Rather then create a fridge type enclosure, why not create a air pass through box that could be attached to a tent/ custom enclosure and just create a closed looped system and the box handles cooling and dehumidifying/drainage.
How cool would it be just to plug it up to the tent and cannatent. Im really to lazy to buid this but you seem like a go getter.

The temp controller is already built into the cooler, or are you guys just trying to control the dehumidifier with something different? Thermoelectric temp controllers are simple devices and readily available. If you’re building a box from scratch then one will be needed, the peltiers should have voltage always applied, not just on and off. If trying to build a larger one, keep in mind even larger wine coolers are broken into zones for the simple reason peltiers are not efficient at cooling larger spaces, you will need multiple units and then must keep them in sync, that’s why they don’t make larger wine coolers or refrigerators that are thermoelectric. Can it be done? Yes. Is it cost effective? No. Easy as that. If you decide to run down that rabbit hole keep us up to date, would love to see how it works, but I already started down that route before realizing how well the current version works, how cheap it is and how easy it is to put together.

I recommend looking into the way peltiers work before plunging too far into trying to build a large one, it’s cheaper to build two small ones, or five for that matter.

Im loving mine I just got this tray to replace the current drip tray.

gooshpoo said:

I wasn't referring to the Arduino and more on the Chinese motor controllers and psu its going to be cycling heating/cooling on/off/reverse etc. over and over Id just would build it with better quality relays. It would make a better system in the long run and scalability would be easier.

Could I make a suggestion its something I have been thinking about. Rather then create a fridge type enclosure, why not create a air pass through box that could be attached to a tent/ custom enclosure and just create a closed looped system and the box handles cooling and dehumidifying/drainage.
How cool would it be just to plug it up to the tent and cannatent. Im really to lazy to buid this but you seem like a go getter.

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Ah my bad. Ya the motor controller I have no luck or experience with. The psu ya I can see where something better might be a good idea if you are gonna use it for long term storage too.

As Hook Daddy said the peltiers don't do well with large spaces so I doubt they would be able to cool something the size of a tent. Guessing at that point one would need to get into a normal compressor style setup. Which I imagine could be done but beyond what I'm trying to do.

Hook Daddy said:

I recommend looking into the way peltiers work before plunging too far into trying to build a large one, it’s cheaper to build two small ones, or five for that matter.

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I haven't dug into crunching numbers and seeing just how many peltiers it'll take to cool whatever size box I'm wanting yet. Kinda eying an old igloo cooler I have in the basement that is like 5ft long. But as you said it will probably require too many peltiers. So if nothing else I will end up building a box out of 2in foam board. If I build something small'ish like the wine coolers I've seen dual peltiers with fans and heatsinks for $20 on ebay. So 2 of those 1 set for cooling and 1 set for dehumidifcation, some temp sensors for the hot and cold sides, and the motor controllers is all I need as I have everything else. Damn foam board costs more than any other part at like $50 a sheet.

@Hook Daddy is right. I dived down the rabbit hole on the practicality of Peltier tech. You can scale up but it comes with too many downsides. The peltiers aren’t cheap or reliable. They aren’t efficient and give you very minimal cooling power compared to other cooling methods. There’s a reason 28 bottle is the largest commercial Peltier powered fridge you can find.

There’s a few people who have attempted a diy wine fridge and they struggled with peltiers prematurely failing and underwhelming cooling capabilities.

here’s my favorite DIY I found. Dude went all out but it’s flawed.

link to the original post: https://www.reddit.com/r/microgrowery/comments/1k203a

Hook Daddy said:

The fan will still run if it ices over, the fins in the back will be covered in a block of ice. Happens trying to go to low rh with that much moisture, unplug the dehuey for half an hour then start again, and set the rh higher, around 73-75, then drop down slowly each day. That’s what I did my last run that was packed fairly tight and not dried at all first and it came out fantastic.

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Thank you for posting this guide, Hook Daddy! I have 2 units built and am debating if I should hang dry first or go right from harvest to the cooler.

I see you've done it both ways; do you get any flat buds going right into the cooler? And for the first few days when RH is high, with your recommended RH at 75%, how do you have your inkbird set? Is it set to like 65% Rh with a 10 point so that it kicks on at 75%, down to 65%, then turns off?

bOGGLER82 said:

Thank you for posting this guide, Hook Daddy! I have 2 units built and am debating if I should hang dry first or go right from harvest to the cooler.

I see you've done it both ways; do you get any flat buds going right into the cooler? And for the first few days when RH is high, with your recommended RH at 75%, how do you have your inkbird set? Is it set to like 65% Rh with a 10 point so that it kicks on at 75%, down to 65%, then turns off?

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To hang dry first or not is just preference. I have never had my dehumidifier ice up when hang drying first, not that icing up is really all that big of a deal. I do get some flat spots on buds sometimes when going straight in, but I don’t flip the buds or try to stop it either, it doesn’t make a big difference to me. I find the slower longer dry time seems to keep more terps, or at least most people think it tastes slightly better going straight in.

I have my Inkbird set for only 1% difference, so when I set it at 75% it turns the dehumidifier on at 76% and back off when rh falls below 75%. That is how you keep the swings smaller, makes sense once you see it working. The dehumidifier will kick on at 76%, but if the buds are fresh and holding lots of moisture still it may go to 80% rh before starting to drop, then the dehumidifier will kick off at 75% but the cold side of the peltier is still cold and the rh will continue dropping to 73% or so, then start to rise again.

I just finished my koolatron. Thank you @Hook Daddy for the instructions. Heres a picture

I finally said screw it and pulled the trigger on ordering all the parts to build something. Still not decided on exactly what size to build the box. Found someplace that said the cannatrol is 2.49 cu ft which is roughly 70 liters which is a bit bigger than the koolatrons. So makes me lean towards a bit bigger box. Seeing how my spare room temp is pretty low for a first test I'm leaning towards just putting everything in a tote. Or heck I could go full ghetto and put it in a cardboard box LOL. My thinking is the cooling peltiers really just need to counteract the heat from the dehumidifier peltier if my room temp is in the right range. From hunting around the net it seems that peltiers make roughly 1.75 times as much heat as they do cold. So 2 cooling modules and 1 dehumidifying module, as everyone here appears to be using should work out fine. I'll have 2 extra modules if cooling really turns out to be an issue.

Still lots of coding left but I did knock out all the variables and if statements. So if again big IF everything works correctly I shouldn't have any of the freezing problems some here have talked about. I coded for reducing voltage if the dehumidifier or cooling modules freeze, back off dehumidifier voltage if the box temp gets too high, etc. Hoping to have the code usable by the time the parts arrive.