A Solar Dehydrator

Image: Solar dehydrator built from left over bits and pieces from our house construction.

The summer solstice is past and summer’s finally here.  The weather has become typically hot and dry, with no rain in sight for weeks.  It’s time to start harvesting the garden before everything dries up and dies.  As part of that process, we decided to build a solar dehydrator.

There are some beautiful designs for solar dehydrator’s available on the web, but in the end, we decided to build one that fit our pocket book, e.g., free.  That means that we designed our dehydrator to make use of left over materials that we had around the cabin.

Essentially, a solar dehydrator is just a square box filled with drying racks attached to a solar collector.  The solar collector needs, at a minimum, a clear panel for sunlight to pass through, and a black surface that can be warmed.  The whole dehydrator is vented so that cold air is drawn in through the bottom of the solar collector, warmed in the collector, thus causing it to rise, and then passed through the drying racks and out a vent hole in the top of the box.  Pretty simple.  The size of the unit can be quite variable, although the longer the solar collector the better.  We placed our solar collector at 45°, which is a compromise between our spring and summer solar angles for our latitude.  The solar collector can be filled with mesh or black painted pop cans for increased solar absorption – we haven’t done this yet, and are still experimenting.

Image: Side view of our solar collector.

Our strawberries are bearing faster than we can eat them, and have become a good test for the solar dehydrator.  I’ve sliced the strawberries into thin slices, and laid them out on the dehydrator racks.

Image: Solar collector showing racks with strawberries.

Image: Nearly dried strawberries.

The smell that is coming from the top vent of the dehydrator is absolutely gastronomic.  I’ve put quite a load of strawberries in, and although it has taken a couple of days, it seems that they will dry quite nicely.  Solar drying is not as fast as using a dryer with an electrical heater unit, but it doesn’t take any power, and isn’t draining our batteries (which we are happily using to run a small cooler to keep our perishables from perishing).

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3 thoughts on “A Solar Dehydrator”

  1. Hello Barb,
    Brilliant design!
    I wonder if a solar fan would help with the thicker juicier stuff. Moving the air over the food .. that sort of thing,
    It’s so warm! We are wondering how long our stored water will last.
    Happy with this first year garden, but it’s getting watered every other day with duck pond water.. you can imagine the growth!
    Great to see the developments of your grand experience!
    Sending apprection to you!

  2. Thanks!

    Air flow is actually pretty good – we almost always have a breeze here, if not a 15 to 25 knot wind, which gets funneled up the vents in the solar collector. We’ve actually had to block the vents when it got too windy!

    Sounds like your garden is doing well – we could use some duck water! We are also worried, as always, about water, but doing better this year than the last two. Our dam on the creek is still giving us running water in the house, although that may only last a few more days, with this heat. We are watering the garden every second day with collected roof run-off, and have planted a lot of drought tolerant veggies, so that they can survive with relatively little water. So we’ll see …

    We are really happy with the dried strawberries – very tasty! I’m drying currants and clover blossoms now.

    Good luck on your place!

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