Homemade Solar Water Heater / Aquecedor Solar de Água Caseira

Uploaded by jaketeater on 17.11.2009

http:/solarhotwater. teaters. com
Hello, my name is Jake.
I am a missionary in southern Brazil at an orphanage.
And I just wanted to share with you about how I built my solar water heater.
In Brazil water is usually heated at the shower head with an instant water heater in the shower head.
It uses a lot of electricity, about 5000 Watts and in the winter it usually is not enough to make a warm shower.
So I decided to build a solar water heater.
Before I get into it, first just a little bit about the location.
We are 25 degrees away from the equator, similar in distance from the equator as the Florida Keys.
We are also 3,500 ft up, or 1,000 meters in altitude. So even though we don't get the same hot climate as the Keys,
In the summer it usually doesn't get up above 90 degrees. In the hottest month the average temperature is 70 degrees
In the winter it will get below freezing, but not low enough to ever freeze the pipes.
A little bit more about the location, the yearly average temperature is 61 degrees.
So that means that the water, as it comes through the pipes in the ground,
It gets into the water tank at about 60 degrees F, or 16 degrees C
A good shower is about 105 degrees F, or 40 degrees C.
So I need to get the temperature up and make up as much as I can.
To get up to that temperature.
And this water heater on cloudy days will get up to 90 degrees F,
Even on rainy days.
On sunny days it will easily get up to 135 degrees F, 55 C
When it is 90 degrees, on the electric shower head I just turn it on half way.
Ever since we installed it I have only had to turn it on full blast once.
So just a little bit about how the solar hot water heater is made,
If we could just get a close up of how I did it,
I use PVC pipe, PVC pipe is only rated to go up to 135 F, or 55 C.
I believe that the limit is there because of the joints in the PVC.
The connections will fail at that temperature.
Now here we have low pressure, just as much as is created by the fall from the hot water tank,
Which is up in our attic.
Now, what I did to make the hot water heater,
I stuck T's together with small pipes in the middle,
So I have a row of T's here, and a row of T's up there.
Then inside this glass, you can see here, there is a florescent light bulb tube.
I cleaned out all of the dust that was inside,
So that it became a clear long piece of glass.
And I punctured both ends so that I could get a 20mm or a 1/2 inch pipe
to go inside of it.
And I have about 32 of these pipes,
The square footage of the collector is about 27-28 sq ft,
or 2.5 square meters.
And its a thermosyphon, as the cold water comes in through here
This is the lowest point on the collector,
And because the water becomes less dense as it heats
It rises and rises up until the highest point,
as the collector is not level, the highest point is over there -
And then it goes up into the top of the hot water tank.
The cold water then replaces it,
it flows down from the bottom of the water tank,
And it just cycles.
I am using the bulbs as an insulator.
Basically a double glazing. It keeps hot air around the pipes.
So that allows it to be heated not just on 180 degrees of the pipe,
But on 360 degrees of the pipe.
Because its not just radiation but also the convection,
produced but the radiated heat.
I did tests with a bulb around the pipe,
and with out a bulb.
With the bulb, within 45 minutes the water heated
from 60 degrees F to 135 degrees F,
or from 16 degrees C to 55 degrees C
With out the bulb, it only heated up to 125 degrees F.
So the bulb added extra efficiency, to the heater
by putting on the florescent bulb.
And on the days when I did the tests,
There wasn't a lot of sun. For most of the day there were no shadows.
It was partly cloudy.
To protect the PVC connections, from the heat
I covered all connects in foam insulation.
And then over the foam insulation,
because the sun deteriorates it, I put tin foil and painted it black
This way, it sturdies the PVC connections, and it also protects them from the extra heat that is in here,
The only heat that will reach them should be the heat of the water.
As it flows through.
Well in North America this wouldn't be the best system,
because you can't put anti freeze in it,
your drinking water flows through it and back into a water tank.
It would have some uses, for example,
it would be good for a pool shower,
in the winter it could be winterized very easily,
this is the lowest section of the water heater,
I can just open up this pipe and drain all the water out,
And then put a tarp over the top so that it wont over heat,
while there is no water in it.
It can also be used as a heater at a cabin,
Just places that would be used during the summer
That way the water could be drained out in the winter
to avoid it freezing.
Now lets go inside and take a look in the attic,
at how I have the water tank setup.
Here we are in the attic
This is my water tank, you can kind of see it here.
Its a 310 liter, or about 80 gallon tank.
Its just a standard cold water tank,
Its almost like Tupperware.
I have 5 pipes going in and out of it.
In the back, its kind of hard to see,
I have the pipe that feeds it cold water,
This pipe here is an over flow pipe
That way the water can never spill out into the house,
It takes the water out to the soffit.
This pipe feeds the house with hot water.
It is above the other pipes
This is the return from the solar hot water heater,
This is the supply of cold water to the heater,
The reason this pipe, that feeds the plumbing in the house,
is the highest, is that way there is always -
Going to be water going in the solar water heater.
Even if my pump fails and doesn't fill my tank up,
And I use all of the water,
I can only use the water to this level.
That way my solar hot water heater
can't over heat because its run out of water.
Another thing that I've done is,
you can see this power cord going into the tank
I bought a bucket heater,
It turns on at 80 degrees F
And off at 110 degrees F
This way its kind of like a back up,
Now on cold days, if I need to,
I could have electrically heated
hot water.
I have also insulated it with spray foam insulation.
I would prefer fiberglass,
But I could not find a cheap,
quick source of that.
here in brazil
The water tank is not completely insulated,
Once I get more money,
I will be able to do that.
Now if you come down here,
into the bathroom, I can show you
Somewhat of a standard
Brazilian shower head.
This shower head has a heating element in it
Right here. It runs at 7500 watts.
This one has three adjustments.
It can run at 2500 Watts, 5000 Watts, or 7500 Watts.
The heating element heats it instantly
and it comes out here.
Its a simple source of hot water
Most Brazilian houses have.
And its great when you have a solar hot water heater
Because on the days when its cloudy
I can just turn it on a third of the way
And it will heat the water, I don’t have to put it on full blast
So it saves a lot in electricity
Standard Brazilian houses
would have a 5000 Watt shower head,
which is equivalent to 50, 100 watt light bulbs
on at the same time.
Or 4 microwaves.
So its quite a bit of electricity to be used
So by having a solar hot water heater
I can greatly reduce my electric bill!
For more info visit:
solarhotwater. teaters. com