Solar Powered Fridge

Kathyhere · #1 03/29/12, 07:22 PM

Found this site where they built a solar powered fridge, thought it was a great idea to at least to have the knowledge of how to build one.

The general idea of the system is based on an old design for desert/dry-land cool storages which makes use of a really high heat chimney to create an up-draft which then sucks cool air in to the storage chamber from below. They designed a long tunnel for the cooled air to pass through on its way of being sucked into the storage chamber and hence be cooled by the ground on the way to the chamber. In order to enhance the cooling of the air on the way to the chamber, if possible, water, by evaporating will take in thermal energy, causing the temperature of the air to fall further.

All the details of the design are at the link below.

Strawberry Fields Eco Lodge Update: Solar Powered Fridge Permaculture Research Institute

halfpint · #2 03/29/12, 09:44 PM

I would love to see data on how well this works in various temperatures and humidity. I found that the double clay pot used to cool works well here when the humidity is low, but doesn't do us any good in the summer when the humidity is high, and I suspect the same thing would apply to this system, although the ground might cool the air a little just because of the lower temperature of the ground.

Dawn

Kathyhere · #3 03/30/12, 07:49 AM

Actually I am thinking something along this design would make a good rootcellar.

But under conditions of having no electric for an extended period of time, knowing how to build something like this that would keep things cooled a bit is better than nothing.

Harry Chickpea · #4 03/30/12, 11:45 AM

Oh my. That is what happens when someone has more brawn than brains.

The ground temps tend to be stable if you dig down deep enough. Using a solar tower to create the low pressure needed to create a breeze will pull air into the tubes at the hottest part of the day, effectively HEATING the air intake. It might not matter too much though, because those tubes are so small and the surface so rough that there will be tremendous friction to the air flow.

What would be tremendously more effective (and far more simple) is a shaded moist area above the root cellar, to constantly keep that patch of ground cooler. If there was a way for the cool water to thermosyphon down, that might be even better.

What was shown was a complete waste of materials and effort.

Kathyhere · #5 03/30/12, 06:16 PM

Looked like it might have worked to me... but I don't know nothing about these things, that's why I come here.