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Re: How we can measure the heat loss in a solar collector?

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Posted by Morris Dovey on January 2, 2008, 12:38 pm
 
alicanguclu@gmail.com wrote:
| Any idea?

Measure energy going into collector.

Measure energy coming out of collector.

Subtract second measurement from first measurement.

--
Morris Dovey
DeSoto Solar
DeSoto, Iowa USA
http://www.iedu.com/DeSoto/



Posted by Solar Flare on January 2, 2008, 1:25 pm
 
Get an identical collector and place in front of the one under test.
Now guess at the standard collector's losses and use the same figure
for the original unit because it is now in the dark.



Posted by Morris Dovey on January 2, 2008, 2:03 pm
 Solar Flare wrote:
| Get an identical collector and place in front of the one under test.
| Now guess at the standard collector's losses and use the same figure
| for the original unit because it is now in the dark.

If we're just going to guess, do we need the second collector?

;-)

--
Morris Dovey
DeSoto Solar
DeSoto, Iowa USA
http://www.iedu.com/DeSoto/



Posted by Solar Flare on January 2, 2008, 2:43 pm
 Nope. We don't, but my way was more accurate.

Now answer the OP's question, if you can, instead of quoting physics
laws.



Posted by J. Clarke on January 2, 2008, 3:47 pm
 Solar Flare wrote:

On a clear day measure temperature rise and flow rate--that gives you
an approximation of the energy coming out (how close that
approximation is depends on how accurately you can measure these
quantities).  From a table figure the insolation per square foot at
that location on that day (make sure to correct for snow cover etc)
and multiply by collector area.  That gives you an approximation of
heat input.  Subtract output from input and you've got losses.

The actual measuring of flow rate is usually the problem.
Thermometers are easy to find--flow meters and low-velocity
anemometers less so.


to email, dial "usenet" and validate
(was jclarke at eye bee em dot net)



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