Self-contained temperature regulated solar powered dehydrator

[Spuzzana]

Current project: Looking for information on how to build a self-contained temperature regulated solar powered dehydrator.

Would like to understand the power requirements for a small motor to control convection in the unit.

The unit need to have temperature control so that it can be set at differnet levels dependant on the produce being dehydrated.

Need to know how many solar cells would be ideal to run such a stand alone unit.

Ideas and technical knowledge greatly appreciated.

Thoughts so far:
12v motor
thermo coupling for temperature control
Light bulbs for heat source regulated by thermo coupling switching on/off dependant on temperature.
36 solar cells 3x6 inches placed in series on a single panel that will achieve about 18 volts.

[Skean Dhude]

Ah! I misunderstood what was being solar powered.

Interesting idea. Use solar to power the unit, solar to heat it as well and just provide the difference.

[Scythe13]

As an idea, although it would make a huge unit, you could solar panel to battery, battery to alternator, alternator to normal dehydrator.

What's your need for portability?

[Spuzzana]

Shean Dhude

Yes solar to power and heat the unit with thermostatic temperature control. Convection is the important part as this will dissipate the fluids that are yielded from the products being dehydrated.

The idea is to be able to dehydrate produce from a hidden forest garden. Produce will vary according to the time of the year. 12 hours is normally long enough to dehydrate most meats, fruits and vegetable. However, there are some that take longer which is often dependant on how they have been treated prior to being dehydrated. E.G. Jerkey normally take about 5-8 hours dependant on preparation. For products that take longer, ideally these would be started one day and completed the next to avoid bacterial contamination.

If someone chooses to keep animals, the dehydrator should be able to dehydrate meat as well. This is normally dehydrated at a slightly higher temperature.

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Scythe13
Once built, portability is not of great consideration. Plan is to be deep into an area that would not normally be frequented by people in transit. The only concern is if (fuck wits) others smell the produce being dehydrated and think they can have an easy meal.

As you are probably aware, when you are hungry, your sense of smell is heightened.

[Scythe13]

I'd just go panel, car battery, alternator, dehydrator, and then a flue to take the smell up high and dissipate it quickly, or down low into the ground to mix the smell with dirt to disguise it.

There is always the option to use strong aromatic plants around it to further disguise the item and process.

How are you going to hide a solar panel in the woods?

[LawAbidingCitizen]

(7 October 2013, 23:02)Spuzzana Wrote: Current project: Looking for information on how to build a self-contained temperature regulated solar powered dehydrator.

Would like to understand the power requirements for a small motor to control convection in the unit.

The unit need to have temperature control so that it can be set at differnet levels dependant on the produce being dehydrated.

Need to know how many solar cells would be ideal to run such a stand alone unit.

Ideas and technical knowledge greatly appreciated.

Thoughts so far:
12v motor
thermo coupling for temperature control
Light bulbs for heat source regulated by thermo coupling switching on/off dependant on temperature.
36 solar cells 3x6 inches placed in series on a single panel that will achieve about 18 volts.

Not exactly sure what you're trying to do, but will you be using batteries to store up the charge from the panels? What Wattage will the panel be?

[CharlesHarris]

For what it is worth, here in the summertime, interior temperature of a parked motor vehicle in full sun can exceed 70 degrees C.

I place fruits and vegetables on pizza trays and position inside my SUV, parked in the sun. Set out in the morning, bring in at duck, monitor progress daily.

The Hillbilly Dehydrator!

[Skean Dhude]

You wouldn't need a battery, therefore no controller. You could build a normal solar cooker, then using a solar panel to power a heater or a fan to heat or cool to keep a constant temp.

Sounds simple enough.

[Lightspeed]

Interesting project.

We dry fruit and mushrooms on curtain net stretched on pine frames. These are left in the sun for two or three days to dry completely.

Smart idea using solar electric. What about car seat heating elements as the heat source? They can even be had with thermostatic control.

see: http://www.ebay.co.uk/itm/Universal-Carb...2ec94a7d26

[Spuzzana]

Hi LawAbidingCitizen

Not certain about storing any excess charge into batteries at this time. This is a first time project. Know very little about electricity so it is a total learning curve.

Having seen solar panels being used in a wide range of applications, the thought process was to consider how this can be used towards an ongoing food preservation scenario.

Maybe if there is enough time I will consider building a total off grid system using batteries.

It is possible to obtain a solar kit to make a 1KH system for £240. The kit includes:

555 3x6 a grade polycrystalline solar cells
180 meters tabbing wire
10 meters busbar
2 x Rosin flux pen 12ml Surface Mount no clean soldering
Set of rubber gloves

Other attributes per cell are:
Average Power (Watts): 1.8 W
Average Current (Amps): 3.6 Amps
Average Voltage (Volts): 0.55 V (up to 0.6 v in sunny conditions)
Dimensions: 3 inches x 6 inches, or 80 mm by 150 mm
Weight: about 6.0g

There are other items that would be needed such as inverter, switches, fuses and breakers.

Hi Lightspeed

What a brilliant suggestion. Car seat heating elements. Can include thermostatic control. The very part I was most concerned about.

Thank you.