Celdas Solares

I live in an all solar house in Northern California. It is a passive design so

the sun heats it by shining in the windows. I solar heat our water and have a 1

kilowatt solar electric charging system providing 110 volts of AC power. The one

thing I could not do was cool the house easily in the summer without taxing the

system. I purchased an evaporative type unit for indoors but it did not do much

good. A compressor type air conditioner would use more energy than I could

supply and a regular evaporative cooler would use a lot of energy. I figured that

some sort of solar cooler could do the trick.

I spent sometime looking for a solar evaporative cooler on the Internet.

Those that I found were bulky, ugly and expensive. Most cost around $ 600.00 and

up. The above pictures are of a Solar evaporative cooler that I made using easily

purchased components to cool our 1600 square foot house. I spent roughly $300 to

make this unit. It is in it’s fourth year of use. If you have some of the components

already you could spend much less. The cost of a new solar panel to power the unit

is around $550 and can be purchased at many local or on line stores.

Afternoon Summer temperatures range between 85° to 95° in this part of

California. The cooler that I purchased is smaller than I should have for my house

size, but it does a good job of keeping the house cool. With the fan and pump

modifications, it maintains a temperature difference of about 15° between the

outside and the inside. As I am writing this it is 4:30 in the afternoon. The outside

temperature is 92° and the inside temperature is 77°. Anyone with an existing

evaporative cooler of any size can make a similar looking cooler, or you can buy

one like I did.

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Build Your Own Solar Evaporative Cooler

I decided to use an existing evaporative cooler because I didn’t want to reinvent

the wheel. All the components are already there, the cooler pads, a trough to

hold water, a float valve to let more water in and a water distribution system. As

you can see from the pictures I

mounted a 12 volt radiator fan in front

of the existing opening and I opted to

leave the existing AC pump, motor and

squirrel cage intact. Since I have 110

Volt AC power available at my house,

on occasions, I use the existing AC

pump and motor after the sun has gone

down to continue cooling the house. I

was concerned that leaving everything

there might significantly block the

airflow, but it seems to work just fine.

You could remove the existing motor

and pump and It might work even

better. If you do use the AC fan, make

sure the 12 Volt fan does not turn as it

could cause it to burn out. I use a coat

hanger inserted through the front and

placed between the 12 Volt fan blades

and it’s housing. It seems a little hoaky

but it keeps the fan from turning.

I purchased the electric radiator fan at a local auto parts store. I paid around

$80 for it and have seen similar fans on the Internet for $35. The pump is a 12 volt

bilge pump that I purchased at Wal Mart for around $14. Make sure that you don’t

use too strong of a pump or you will blast the water into the feeder tubes.

At full speed the fan pulls 5.5amps @ 12 volts. The bilge pump pulls around

1.5 amps @ 12 volts. A 100 watt solar panel will power the fan and pump nicely. I

am using a Mitsubishi 110 Watt panel that is mounted on a solar tracker that I

made. The panel and tracker are mounted on the ground in front of the cooler. In

previous years I have placed the panel flat on the roof just above the cooler. That

worked fine for most of the day. The tracker extends the time in the afternoon

when the summer temperatures are keeping things hot.

You can decide for yourself how you want to mount the fan. I drilled holes in

the sheet metal and used sheet metal screws to attach it. I did have to do some

cutting of the sheet metal with a Dremel tool to make it fit. Radiator fans can be

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hooked up two ways electrically so the fan can blow air in either direction. Make

sure you hook it up correctly to blow the direction you want.

I removed the existing front cover to expose the opening. I then placed the fan over

the opening to determine the best fit and drilled

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