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pump for a diy solar thermal collector? Answered

i am building a diy solar thermal collector using a house radiator painted a black matt paint and i was wondering what would be a good cheap pump to use to circulate the water?  thanks.


If you build your setup so that two small RESIVOIRS are located at the top... then you could use a GARDEN WATER FOUNTAIN PUMP just as "Koosie" suggests.  You dont need much "head" using this setup.  as long as the two RESIVOIRS are located next to each other AT THE TOP of your setup, then the little pump will pump from one resivoir over to the other resivoir.  Six inches of head is all you will need.  (head is the ability of a pump to pump UP HILL)   This also eliminates ANOTHER problem with circulating water, is AIR BUBBLES in your pipes.  There will be NONE of those airpockets in this system... because any air in the system will bubble harmlessly out the resivoir... not into the pump.  I believe those little pumps can pump 60 gallons per hour too!!! that is nothing to sneeze at!  This resivoir and tiny-pump method will work PERFECTLY when circulating water... but not when trying to PUMP or LIFT water out of a low area.  The reason is due to PUMPING water in the UP direction only-- requires a lot of head.  Your application is CIRCULATING water... so this will work in your case.

 thanks for the answers i was also wondering, Ive done the framework for it and the radiator fits perfectly into the frame, i was wondering should i have made the frames bigger and allowed more space for the radiator?

and for the glass i am going to use low E glass


Normally these systems shouldn't need a pump. They rely on the principle of convection to circulate the water. Warm water rises and so it can be taken from the top and cooler water drawn in at the bottom.

But, I agree, a little help driven by solar power will never go amiss.


8 years ago

Those pumps that you use for garden water fountains should work well.
Might not last that long, though.

Take  a look at the little DC pumps that overclockers use for their souped up PC cooling systems - only a few watts, but not for much water head.