Cannabis Drying/Curing Refrigerator - Build Questions - Need Help!

[Diverge]

For whatever it's worth, I picked up a refurbished wine refrigerator for $150 delivered from eBay. I figure for $150 it was a cheap experiment. I eventually plan on modifying it in the future.

This is the one I got for reference: https://www.amazon.com/NewAir-NWC023SS00-Single-Freestanding-Stainless/dp/B087T5VW3W/

It has a max temp of 64 degrees, but didn't seem to kick on the compressor until I adjusted it to 63. Here's some sensorpush data. You can see it's humidity swings pretty wide, probably when the compressor turns on and off.

 

[MIGrampaUSA]

For whatever it's worth, I picked up a refurbished wine refrigerator for $150 delivered from eBay. I figure for $150 it was a cheap experiment. I eventually plan on modifying it in the future.

This is the one I got for reference: https://www.amazon.com/NewAir-NWC023SS00-Single-Freestanding-Stainless/dp/B087T5VW3W/

It has a max temp of 64 degrees, but didn't seem to kick on the compressor until I adjusted it to 63. Here's some sensorpush data. You can see it's humidity swings pretty wide, probably when the compressor turns on and off.
View attachment 1306872
View attachment 1306873

What kind of modifications do you have in mind for it? Anything you're thinking of doing to address the humidity spikes? What you're doing is exactly what I'm considering. I wanted to experiment first with my old refrigerator before buying a glass front beverage refrigerator.

 

[Diverge]

What kind of modifications do you have in mind for it? Anything you're thinking of doing to address the humidity spikes? What you're doing is exactly what I'm considering. I wanted to experiment first with my old refrigerator before buying a glass front beverage refrigerator.

The goal is to get some sort of humidity control. I bought a tiny dehumidifier that has an external drain line. Pretty much what has already been discussed here. I might replace or modify the controller for the compressor with an Arduino.

Next step is probably just putting the tiny dehumidifier in it to see how it affects the refrigeration and see if it can actually reduce the humidity, and howuch they fight each other.

I'm probably a while away from getting to this though. Too many projects and things to do. I just thought I'd show some data on what you can expect out of those refrigerators unmodified.

 

[MIGrampaUSA]

The goal is to get some sort of humidity control. I bought a tiny dehumidifier that has an external drain line. Pretty much what has already been discussed here. I might replace or modify the controller for the compressor with an Arduino.

Next step is probably just putting the tiny dehumidifier in it to see how it affects the refrigeration and see if it can actually reduce the humidity, and howuch they fight each other.

I'm probably a while away from getting to this though. Too many projects and things to do. I just thought I'd show some data on what you can expect out of those refrigerators unmodified.

Thanks for that. It's been informative. The humidity spikes aren't surprising. It's what people are doing to control it is the information I'm looking for ... just like you shared. Can you post a link to this mini dehuey you were speaking of?

 

[Diverge]

Thanks for that. It's been informative. The humidity spikes aren't surprising. It's what people are doing to control it is the information I'm looking for ... just like you shared. Can you post a link to this mini dehuey you were speaking of?

Sure , no problem: https://www.amazon.com/gp/aw/d/B0BDZ51ZMJ

 

[RootsRuler]

Unless you're not able to drop the humidity in your room when you grow I'm not sure why you can't cure in that same environment.

 

[MIGrampaUSA]

Unless you're not able to drop the humidity in your room when you grow I'm not sure why you can't cure in that same environment.

Humidity isn't an issue. I'm not able to get my drying temps below 70F once the warmer weather rolls around again. Then everything dries too fast.

I'm stacked up with plants right now and I'll be lucky to be done by the 1st of July. Most years, I'm wrapping up indoors late April/early May ... that won't happen this year.

 

[RootsRuler]

Humidity isn't an issue. I'm not able to get my drying temps below 70F once the warmer weather rolls around again. Then everything dries too fast.

I'm stacked up with plants right now and I'll be lucky to be done by the 1st of July. Most years, I'm wrapping up indoors late April/early May ... that won't happen this year.

What dry temp are you going for?

 

[MIGrampaUSA]

What dry temp are you going for?

60F tops ... If I could dry at 55F, I'd be smiling like this

 

[RootsRuler]

While drying and curing at that temp would be great I've found that weed can be cured properly at up to 75* with humidity as high as 65%. Is it ideal? No but you can have excellent results at those higher marks but you just need to be more on top of the process. If I'm in the dry phase and the temp is higher I check the product and move on to the next phase right before their ready to go. The time to transition to the next phase usually gets them there at the point you wanted them to be and don't get overdry. In other words I try and anticipate the continued drying that will happen and go from there.

 

[MIGrampaUSA]

While drying and curing at that temp would be great I've found that weed can be cured properly at up to 75* with humidity as high as 65%. Is it ideal? No but you can have excellent results at those higher marks but you just need to be more on top of the process. If I'm in the dry phase and the temp is higher I check the product and move on to the next phase right before their ready to go. The time to transition to the next phase usually gets them there at the point you wanted them to be and don't get overdry. In other words I try and anticipate the continued drying that will happen and go from there.

I can make it work. It seems my weed dried during summer months takes longer to cure ... which leaves me thinking that I left more terps behind during the dry than I do during the colder months here. I'm looking at using a refrigerator connected to one of my temperature controllers for consistency year round ... even if I have to run a small dehuey inside of it to keep rH stable.

 

[RootsRuler]

I can make it work. It seems my weed dried during summer months takes longer to cure ... which leaves me thinking that I left more terps behind during the dry than I do during the colder months here. I'm looking at using a refrigerator connected to one of my temperature controllers for consistency year round ... even if I have to run a small dehuey inside of it to keep rH stable.

I can see how that could work but........Household refrigerators typically run at 65%RH at around 38*. What you are looking for is a vessel that can lower the temp to keep from gassing your terps but dry enough that you don't get mold and the low humidity will help draw moisture out of the flower. That is your goal.

In a normal household refrigerator you should be able to set the temperature at 55* and expect an RH of around 70% - 80% RH. A specialized refrigerator made for something like produce should be able to run at 55* at sub 60% RH. Rather than try and DIY something that may or may not work I would look to industry first to see if there is already a product made that falls within the parameters you are looking for. Obviously price matters but a refrigerator like this could be had used for cheap and work better than what you are trying to do. Even if this specialized fridge is too pricey just getting a look at the design should inform your solution.

Not saying your idea won't work but I do see some design flaws in concept. Trying to run a dehumidifier inside a refrigerator will be a lesson in futility. The fridge will be fighting the heat from the dehu. The temp swings will drive you crazy and the compressor will be constantly running trying to correct the heat coming from your dehu. There's a reason the dehumidification equipment is on the outside of the fridge. The way a fridge removes humidity is that they run the air over cooling coils that turn the water vapor in the air into solid liquid. The liquid drops out of the air into a collection pan and gets evaporated away from the heat of the compressor and other fridge components.

In a refrigerator design your issue is not temp control moreso it's humidity control. Find the fridge that can hit both those parameters.

 

[MIGrampaUSA]

I can see how that could work but........Household refrigerators typically run at 65%RH at around 38*. What you are looking for is a vessel that can lower the temp to keep from gassing your terps but dry enough that you don't get mold and the low humidity will help draw moisture out of the flower. That is your goal.

In a normal household refrigerator you should be able to set the temperature at 55* and expect an RH of around 70% - 80% RH. A specialized refrigerator made for something like produce should be able to run at 55* at sub 60% RH. Rather than try and DIY something that may or may not work I would look to industry first to see if there is already a product made that falls within the parameters you are looking for. Obviously price matters but a refrigerator like this could be had used for cheap and work better than what you are trying to do. Even if this specialized fridge is too pricey just getting a look at the design should inform your solution.

Not saying your idea won't work but I do see some design flaws in concept. Trying to run a dehumidifier inside a refrigerator will be a lesson in futility. The fridge will be fighting the heat from the dehu. The temp swings will drive you crazy and the compressor will be constantly running trying to correct the heat coming from your dehu. There's a reason the dehumidification equipment is on the outside of the fridge. The way a fridge removes humidity is that they run the air over cooling coils that turn the water vapor in the air into solid liquid. The liquid drops out of the air into a collection pan and gets evaporated away from the heat of the compressor and other fridge components.

In a refrigerator design your issue is not temp control moreso it's humidity control. Find the fridge that can hit both those parameters.

I haven't purchased anything at this point. I have a spare refrigerator and an extra temperature controller which is what got me thinking ... However, that high humidity situation has been stuck in my mind. What I would like is one of these:

Cannatrol Cool Cure

The Cannatrol™ Cool Cure Box with patented Vaportrol™ Technology, for the first time, gives the small grower precision control over the dry/cure process from start to finish, regardless of the climate conditions. Dial in the optimal conditions and time for your dry cycle, dial in the cure...

cannatrol.myshopify.com

It's $1600 + tax and shipping so I don't yet even know what shipping would be. I suppose I could finance it but should I? ... probably not. I can get the kind of glass front beverage/wine refrigerator with humidity control (how much, not sure ... didn't dig that deep yet) starting around $400. I'd do that, but not the $1600.

Edit: I also thought about using one of those extra large desiccant tubs like people use in their basement in an attempt to regulate humidity ... I'm not convinced it will work as well in practice though.

 

[RootsRuler]

That's pricey. It's essentially a small fridge with a good dehumidifier. A comparable fridge would be something like one they use to dry age meat but those are pricey too.

Here's someone that converted his refrigerator to dry age meat. If you scroll down you'll see a picture that shows a hygrometer he keeps in the meat locker. It reads 61.5* and 53% humidity. That's right where you want to be. He added a humidifier to his for the meat. Doubt you'll need to do that part.

How to Convert a Refrigerator for Curing Meat or Aging Cheese | Have YOU Ben Starr Struck?

Post pics and give me a shout out once you've completed your cure chamber. An anonymous ounce received through the mail would not be rejected.....kidding....

 

[MIGrampaUSA]

I'll be checking that out for sure ... thanks for the link.

That's exactly what I thought myself about the Cool Cure machine.

 

[RootsRuler]

Let me add that you may want to run your fridge and put a hygrometer in it to see if you can reach the conditions you are looking for with just the fridges controls. The fridge may already be able to hit the zones you're looking for.

 

[MIGrampaUSA]

Let me add that you may want to run your fridge and put a hygrometer in it to see if you can reach the conditions you are looking for with just the fridges controls. The fridge may already be able to hit the zones you're looking for.

I have a number of hygrometers. A couple of them are bluetooth enabled and you can view the history and current conditions right from your smart phone. My refrigerator is moisture controlled. It's not that old either so it could surprise me in how well it does. I'll haul it in from the garage this weekend and see what happens. It will be a dry run so it won't show the same humidity readings I would have with drying buds inside it. It will be useful information though.

 

[RootsRuler]

I have a number of hygrometers. A couple of them are bluetooth enabled and you can view the history and current conditions right from your smart phone. My refrigerator is moisture controlled. It's not that old either so it could surprise me in how well it does. I'll haul it in from the garage this weekend and see what happens. It will be a dry run so it won't show the same humidity readings I would have with drying buds inside it. It will be useful information though.

Yes. At least you'll have a base line. Then you can figure in what the rise in humidity would be once you have product in there and where you need to be so that the numbers equalize into your zone.

 

[PahPahCee]

Hi dudes, first post on here. This is my “Canna Troll” recreation.

Do not confuse compressor fridges with thermoelectric peltier wine coolers. The dehumidifier is hooked up to an inkbird controller. The Dehum is also using a “peltier.”

You can easily maintain 60F and 60% humidity. Or really whatever range you want. No crazy temp or humidity swings.

 

[RootsRuler]

I've heard anecdotal accounts stating that Peltier is not as efficient at removing humidity as a traditional dehumidier is especially when it comes to removing larger amounts..

Do you have to modify the cooler at all or are you working within its operational parameters?