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Two Collectors
Using Aluminum Gutter Downspout Absorbers
These are two very interesting solar air heating collectors that use
aluminum gutter downspouts for the absorber.
Both collectors happen to be done by Scott, but its two different
Scotts :)
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Scott 1's
Low Profile Collector
Scott and Brad's collector uses the
downspouts for the absorber, but also is a nice solution to a situation where
you want to get some solar collection with little to no visual impact so as not
upset the neighbors.
This is the finished low profile collector.
Its only 1 ft high and is barely
visible -- its 24 ft long.
This gives an idea of the internal
construction. The rectangular tubes are aluminum gutter downspout tubes,
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Air inlet and outlet at center |
Air makes a 180deg turn at each end, goes
across the top, and then comes back to exit vent. |
A pretty neat way to get some
collection area in without being very visible at all. Scott feels that he
could have made the collector twice as high without making it much more visible,
which would get the collection area up to 50 sqft.
For a
full
description of building the collector, how its performing, and some "what I
would do differently" comments on Scott's site here...
Scott also did this collector... and
is the founder of the
Yahoo Simply Solar group...
Scott 2's Bigger
Downspout Collector
This is a much larger collector from
Scott 2, that also uses aluminum gutter downspouts for the absorber.
This shows the internal arrangement
for the collector.
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The plenum at the far end of collector |
The inlet and outlet vent plenum. |
Another unique feature is that the
collector can be disassembled and taken for the summer.
For a more complete description,
see the bottom half of this page on Scott's website...
A Couple Thoughts on these
Collectors
These are a couple thoughts on the
two collectors -- both of which I think show some very original thinking.
- The low profile collector idea
seems pretty neat to me. It shows that you can get some worthwhile
collector area even where a larger, conventional collector might be visually
objectionable.
I think we tend to loose track of
the fact that when you build a collector yourself, you can build it any
shape you want to.
- These collectors offer some of
the same advantages of the
"beer can" collectors. They achieve the same sort of good flow distribution and large heat transfer
area as the can collectors do, but with a lot less work.
- To me, both collectors have
what seem like rather long flow paths compared to most air heating
collectors. It seems like a flow path length of 20 ft (more or less)
is usually enough to get a good temperature rise, and might do so with
somewhat less fan power than these longer paths? One way to do
this if the house geometry allowed it would be to have an inlet plenum on
one end and and outlet plenum on the other end -- so the inlet and outlet
would be on opposite ends of he collector -- along the lines of the
TEA collector...
- The larger collector spaces the
downspouts away from each other, and I have to wonder if this is not costing
some performance. It would be nice to know what fraction of the sun
that lands between the downspout runs ends up as heat to the room vs being
lost out the glazing?
Also wonder if the collector efficiency could be improved a bit by squishing
down the downspouts into a flatter but wider shape so that there was less
open space between them? Maybe run them between a couple rollers to
flatten and widen them a bit?
Thanks to both Scott's for doing this
work!!
Gary December 12, 2009
