This is getting rather off-topic perhaps, but I should like to comment on
what
Ross McCluney <[EMAIL PROTECTED]> wrote:
>One thing I forgot to say is that when you have one collector facing
> East toward the morning sun, if
> the panels are placed in series, the heat collected by the East panel
> will be radiated out by the West panel facing away from the sun. If
> they are in parallel, the same problem is experienced, but it is the
> heat the "hot" panel has put in the tank which is radiated by the "cold"
> panel.
This seems to say that a panel facing away from the sun radiates more heat
than one facing the sun. This is not so. Any object radiates the same amount
of heat regardless of the temperature of its surroundings. Assuming it does
not change color, the only factor affecting the amount of heat radiated is
the
temperature of the panel. As the heat radiated is proportional to the fourth
power
of its absolute temperature, a panel at 52 degrees C radiates twice as
much as it does at 0. At 86 degrees it radiates three times as much.
The advantage of parallel connection is that the total water flow rate is
much
higher, so the temperature of the panels is reduced and they radiate less
than
they would if they were connected in series.
Conversely, the heat absorbed is not affected by the panel's temperature, but
is greatly affected by facing the sun. The net effect, as Ross states, is
that a
panel facing away from the sun may radiate more than it absorbs.
Chris Lusby Taylor
Email: [EMAIL PROTECTED]
(Formerly [EMAIL PROTECTED])
