[Greenbuilding] solar heat collection

[Nick Pyner]

Indeed.

I suspect the problem here is that he is talking of mixing volumes - equal
volumes of static medium, and all at 100% efficiency. Unfortunately, what
everybody else is talking about is unequal volumes of medium that is very
much in motion, and who recognise that 100% efficiency is somewhat fanciful.

When the circulating mediumn enters the tank at 180F, there is only one
objective, and that is to extract as much heat as possible before it gets
out again. This is achieved by having the greatest temperature difference
possible, and for as long as practical. This is the holy grail gradient I
alluded to before. To achieve this, you run it as long as practical through
the coldest water available, which is quite easily found at the bottom of
the tank. I guess this also explains why the energy circulating through an
electric heating element is employed in the same way.

This is not a new science, every solar heater design ever opened up does
this, certainly every design I have seen. Indeed I understand that a
principle reason why rooftop water heaters with a horizontal tank suffer
declining popularity these days is that they don't do it very well.

Reading through that post several times, I believe it is implied, but not
actually said, that the heating medium effectively travels vertically
downward through the tank, from the hotter to the colder. In short, it acts
as like a co-flow rather than a contra-flow heat exchanger - the world's
first, and probably the last.

I have never seen such a thing and therefore submit this is a reflection of
the inventor's eternal dilemma that must always be addressed - "how come
nobody has thought of this before, is this a novel breakthrough, or just
another silly idea clogging up the files down at the Patent Office?"

Nick Pyner

Dee Why   NSW

-----Original Message-----
From: greenbuilding-bounces at lists.bioenergylists.org
[mailto:greenbuilding-bounces at lists.bioenergylists.org]On Behalf Of
Clarke Olsen
Sent: Thursday, 5 July 2012 11:20 PM
To: Green Building
Subject: Re: [Greenbuilding] solar heat collection


All heat exchangers have a problem; transfer can never be total. Shouldn't
running through the
greatest differential extract the most? I can appreciate the concept of
obtaining a high temp. in the
upper strata, but storage considerations suggest the efficiency of more
uniform temperatures.

Clarke Olsen
cla

On Jul 5, 2012, at 7:44 AM, Corwyn wrote:

> If you run through the warm box and then the cool box, the top box (and
the water when it is done) end up at 165°, then the cooler box and the water
end up at 142.5°.  So you have extracted 7.5 more degrees of warmth from the
incoming water, so more efficient; plus you have a max temperature of 165°
rather than 150° so more stratification (higher usable energy).
>
> Thank You Kindly,
>