How to build an efficient dehydrator with off the shelf components

Thread Starter

PDXone

Joined Aug 16, 2020
5
Unit should be 5Ft H x 2Ft W x 2Ft D

  • i want it to be able to handle high humidity fuits and veggies
  • I am thinking of buying one of those PID controllers
    -- I need help figuring out what kind, how to wire it, and apparently those things need to be tuned?
    -- My train of thought was that the controler can help maintain a stable temperature and possibly humidity as well
  • I think that a 16" exhaust fan like the ones used for HVAC can be used for this project, since they are capable of variable speed
    -- I don't know if this kind of fan may be too much, but my idea is to have a very sturdy component, since it wil be used for extended periods of time
  • I have no idea of what to use for a heating element
    -- Minimum temp of 80F Maximum temp of 250F
    -- I have seen some convection oven assemblies on e-bay ( something like a heating element that has 2 metal fans )
    -- I dont know if something like that can be controled by the PID
  • I have no idea of what type of sensor I need to buy fo the humidity aspect
    -- Especially one that is fully compatible with the PID

I am considering the idea of buying a busted fridge off my local appliance repair shop, and use for the ready made unsulated box that already has a door that can maintain a good seal.

I just dont have eough resources to afford a 2-to-5 thousand dollar commercial unit. I have certainly found some cheper ones on AliExpress but the durability is a big concern for me.

Any help AND feedback wil be greatly appreciated.

TX.
 

Thread Starter

PDXone

Joined Aug 16, 2020
5
Hello,

Thank you for the prompt response. Those plans have a lot of good information and I appreciate you taken the time to find the article as well. Granted, I am not an expert so I dont mean to contradict your recommendation, but I just dont like the idea of using christmas lights as a heat source.

I would like to gave a setup that can maintain a certain temperature, without me having to check on it constantly.

I am finding lots of info, but nothing that approaches the idea as described in my firs post. The document attached is the most useful I found, so far.
 

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shortbus

Joined Sep 30, 2009
7,921
Granted, I am not an expert so I dont mean to contradict your recommendation, but I just dont like the idea of using christmas lights as a heat source.

Did you see in your PDF the next to the last paragraph on page 1?

Personally I think you're over thinking this, when you talk about using a PID controller, I can almost guarantee no store bough home on uses one of them. I'd go with one of theses in the temperature of your choosing - https://www.sensata.com/products/temperature-sensors-and-switches
 

Thread Starter

PDXone

Joined Aug 16, 2020
5
Hello there :)
Yes, you are correct an electric heater (I am guessing like a space heater) is more alligned with my Idea.

I think the devices listed below could make things a bit less complicated and I am very much looking forward to read your feedback.

https://www.amazon.com/dp/B01LL4SNIE/ref=cm_sw_em_r_mt_btf_awdb_Gb7tFbZ2310KW

As I understand it, the devices are plugged to home outlet and serve as a mediator between the power outlet and the space heater or a fan.

Thanks again.
 

shortbus

Joined Sep 30, 2009
7,921
Yes, you are correct an electric heater (I am guessing like a space heater) is more alligned with my Idea.
You must be reading something other than the PDF you posted earlier. The paragraph I was talking about was the guy building that using many 75 watt light bulbs for heat.

I think the devices listed below could make things a bit less complicated and I am very much looking forward to read your feedback.
I would never do it like your doing so have no idea if those would work. You don't seem to want to listen to what I say so I don't know how much more help I can be, you have already made up your mind on what you want to do.
 

Thread Starter

PDXone

Joined Aug 16, 2020
5
I apologize for having given you the impression that I wont listen to your opinion and guidance.

While I was still reviewing the article you shared and the one I found, I was also attempting to combine ideas from both. The controllers i mentioned seemed like a good idea at the time, since they seemed to me like a plug and play option.

I will go back to reviewing your recomendations, and the article you shared as well.
 

shortbus

Joined Sep 30, 2009
7,921
I don't know if you paid attention to the size of the one in your PDF, but it is huge. Is that what your trying to make, an industrial sized one? Heat isn't really needed for small ones, and the heat must be kept away from the food, air movement is more important. Not huricane or tornado type movement just more of a breeze. What food are you dehydrating?
 

Thread Starter

PDXone

Joined Aug 16, 2020
5
Hello

Yes, I intend to build a unit about the size of a refrigetator. No less than 5ft. tall by 2ft. wide by 2ft. depth.

I want to dry fruits and veggetables, with a particular interest in high moisture items such as tomatoes or pineaples.

Thank you again for your feedback.
 
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