misolarcasero.com
flag-english-language
flag-spanish-language

My water pump for my solar heater

image-cover

I'm going to tell you about the water pump I use in my home solar heater, and the path I had to take to find the one that was perfect for the case.

Fish tank water pump

This first model of solar water pump.
It was a fix because at that time the market was not exactly wide in this type of products.

I put a typical fish tank pump in an airtight container.
Finally the power was very low and I had many problems with this flow system.

It is not at all recommended.
The worst of the problems is that being a large room the capacity to fill with air was very easy.

Pump for fish tank in a sealed glass
Pump for fish tank in a sealed glass

A pump for caravans

Commercially sold water pump of the inline pump type very popular for use in caravans. (Comet brand)
But I had a bad experience and burned 2 in a very short time.

It does not support warm water.
The internal seals expand and the engine floods. (with the inevitable death of the same)

If someone opens this pump, they will find the typical little engine that toy cars had.

Totally inadvisable.

caravan pump
caravan pump

My own homemade water pump

And in the absence of pumps and a little confused, I made my own homemade water pump.
I'm not saying that it is advisable in the long term, but it worked very well for me and I had it for 3 months without giving me any kind of problems.

The only problem was that I made the shaft a little long, and the vibrations made a little noise sometimes.
Sometimes when the water was very hot, a few drops came out between the rotor shaft and the seal.

But the flow was good and it supported the hot water quite well.

Brushless centrifugal hot water pump

This is the pump I am currently using.
It is a very good quality pump, powerful, quiet.
It has quality seals that I don't have to worry about tightness and hot water.

It is difficult to find this type of solar water pump at reasonable prices.
This pump has a very different concept.
And its rotation action is not done through a physical motor.
So It is not an internal coil that creates the magnetic field from a perfectly insulated internal chamber and makes the blades spin.

Because of this inductance that makes the motor spin without contacts or friction, it is called brushless.

Brushless centrifugal water pump
Brushless centrifugal water pump

They can go up to 4 or 5 meters, depending on the model.

Good for its characteristics:

The last point makes it perfectly ideal for our home solar water heater.
I have been using and selling many of these for a long time.

It is difficult to find this type of solar water pump at reasonable prices.
Almost all are submersible and low power.
Either that, or they offer you one of those where 2 guys come out of the storage room carrying the pump and asking if you have the car away.

It works perfectly to move hot water at a more than decent pressure.
Its size does not make it a good judgement. It could seem like a small thing because of its appearance.

It is also very suitable for liquid cooling for PCs and any experiment that requires such special characteristics as temperature and durability.

What is a brushless water pump?

Anyone who has studied basic electronics or has disassembled or blown up an engine knows the following.
The interior of the engine is a piece very similar to a spinning top. Because it has a cylindrical body, and a transverse axis.
At the top of the axis, there is a small cylindrical head.

Do you know the Scalextric cars? They work with brushes that drag on the track.
Or the bumper cars at the fair, which are powered electrically by a cable that drags a mesh on the ceiling?
Or the trains, which have a strange contraption that pushes the cables of the power line.
Well, this is what the motors are like inside, the coil is powered electrically by "rubbing" against 2 brushes that are inside the casing.

Well, the brushless motor and the motor with brushes, are like the analogue of the conventional train and that Chinese train that floats.
The interior (rotor) rotates by an inductive current, at a distance.

As there are no brushes and no friction, the motor rotates freely. The only friction is the clamping of the shaft ends.

Advantages of the brushless motor

It is totally different from conventional motors.

I started using it because it is obviously the most suitable for this price level.
The reality is that spending 200€ In a recirculation water pump, when we hardly need any power and a gentle recirculation is more convenient, it is not very logical.

But people started asking me for it, so I made a small stock so that people could have it quickly.

Characteristics of a brushless recirculation pump

One of them.

The motor electronics are perfectly sealed, so it appears to be like a kind of epoxy resin.
The insulation and sealing are so good that it can be used with complete confidence as a submersible pump.

Technical characteristics:
– It works with any direct current transformer, which is 12V and 1A, because it consumes 12W. If you put a cheap transformer of those that the Chinese sell for 3€ you will not be able to start it. It is advisable to use a universal transformer for laptops and select the voltage at 12 volts.
– It works submerged and without submersion, if we use it without submersion it will be better because we do not subject the cable and its insulation to water.
– Flow: Between 500 and 600 liters / hour (this is almost 9/10 liters / minute)
– Pressure: Up to 5 meters high.
– Ceramic&zirconium axis.
Ceramic&zirconium is expensive and is quality, it does not rust, does not expand, and is very hard, although at the same time it is extremely rigid like tungsten carbide and can be broken more or less easily.
For those who do not know it, it is what is now used to make dental implant parts, or ceramic&zirconium rings that do not scratch. Or these new white pans that are now available that do not scratch either.

Document created by Pedro Reina Rojas
3 de April de 2013
submersible or surface pump, Powerful and cheap pump, Solar water pump