DeSoto, Iowa USA
Morris Dovey wrote:
"Type 1 Panels
The Type 1 panel has a bottom intake and a top discharge, with a straight path
connecting the openings. The trap/exchanger occupies most of this pathway. The
simplicity of construction and minimum material content makes the Type 1 panel
the most popular choice for amateur builders. The advantage of Type 1 panels is
that it is designed to heat the coolest air (near the floor). Its disadvantages
are it insulates only as well as its glazing; and that, without some mechanism
to prevent airflow during periods of darkness, it can operate in reverse. The
most frequently used mechanism used to prevent airflow closes the top opening,
which still allows cooled air to spill out the intake opening - better than
nothing at all; but definitely not the best solution."
I think that another advantage of this one is that it has the shortest and least
obstructed air path through the collector. It seems that this is a key
advantage when you only have buoyancy forces moving the air.
You can add a poly film back flow damper on the bottom vent, its just a bit more
awkward to build than the top vent ones -- for that matter, you could put them
on both upper and lower vents.
You could also add insulation to the back wall.
One disadvantage (to me) is that the when you discharge the hot air at the
ceiling, it tends to stratify the air in the room. This could be good if you
placed thermal mass just under the ceiling, but if you want the heat quickly
distributed tot he room, some kind of fan (like a ceiling fan) to keep the room
air mixed up is needed.
Overall, I think this design has a lot going for -- I'd have to see test data on
the other two to be convinced that they perform as well.
My 2 cents :)
Small test on David Delaney's flow organizer collector:
"Build It Yourself" Solar Projects
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