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Solar Heat Grabber

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Calico Moon (Jeanine)

unread,
Nov 30, 2001, 11:35:37 PM11/30/01
to
A million years ago the Mother Earth news had plans available for a
solar heat grabber that is attached to your window.

I have scoured my back copies with no luck.

If any of you have these plans I would be interested in purchasing a
copy of same.

Thanks.


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/ \
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_/\_/\_/\__ _/_/\_/\_/\_/\_/\_/\_/\_/\_/\_
| | | |( ( | | | | | | | | | |
| | | | ) ) | | | | | | | | | |
| | | |(_( | | | | | | | | | |
| | | | | | | | | | | | | | |
| | | | | | | | | | | | | | |

Calico Moon
cal...@elemeno-p.com

N. Thornton

unread,
Dec 1, 2001, 3:15:17 PM12/1/01
to
Almost all the light and heat reaching a window will be converted to
heat in the house anyway. Putting a black thing by the window won't
achieve anything.

prrrrrr.

Bill Roosa

unread,
Dec 1, 2001, 3:56:45 PM12/1/01
to
These things hang outside and below at an angle to the window. Kinda like a
mini solar hot air panel for the window. Construction is basic thermosiphon
stuff. They can increase the solar gain on a south facing window by a
factor of 2!
Bill Roosa
"N. Thornton" <big...@meeow.co.uk> wrote in message
news:a7076635.0112...@posting.google.com...

Bill Roosa

unread,
Dec 1, 2001, 3:58:45 PM12/1/01
to
Go to the library and look up solar heating. There where three in my
library with these thing in them. Construction is basic let me know I you
want a concept to go from.
Bill Roosa
"Calico Moon (Jeanine)" <cal...@elemeno-p.com> wrote in message
news:3c085dc5...@news.CIS.DFN.DE...

N. Thornton

unread,
Dec 2, 2001, 2:37:18 PM12/2/01
to
Sounds a bit like the thornton mirror, only more complex. I use a
Thornton mirror here, it nearly doubles the heat and light coming into
the window.

It is a near horizontal mirror outside the window at sill level. It
provides a little free winter heat, not a great deal, and pays for
itself many times over.

I calculated what such mirrors saved on bills over their lifetime, and
it added up very nicely. Have to dig out the figures.

David Delaney

unread,
Dec 4, 2001, 6:46:52 PM12/4/01
to
"Calico Moon (Jeanine)" <cal...@elemeno-p.com>

> A million years ago the Mother Earth news had plans available for a
> solar heat grabber that is attached to your window.

See William A. Shurcliff, "New inventions in low-cost solar heating", Brick
House Publishing Company, 1979, out of print, but sometimes available at
<www.ababooks.com> and in libraries.

Shurcliff describes many "solar heat grabbers" (he doesn't call them that),
including cheap reflectors to increase the sunlight coming through the
window. One interesting device augments the solar cross section of the
window without blocking or augmenting sunlight coming through it. The device
consists of a black area on the exterior wall around the window, and an
exterior plastic film over the window extending past the edges of the window
to the edges of the blackened area. Convection, or a blower, transfers hot
air from the small sunspace thus created into the house. Shurcliff
describes many arrangements for getting the air into the house.


Bob Lewis

unread,
Dec 4, 2001, 11:48:05 PM12/4/01
to

David Delaney wrote:

> "Calico Moon (Jeanine)" <cal...@elemeno-p.com>
> > A million years ago the Mother Earth news had plans available for a
> > solar heat grabber that is attached to your window.
>
> See William A. Shurcliff, "New inventions in low-cost solar heating", Brick
> House Publishing Company, 1979, out of print, but sometimes available at
> <www.ababooks.com> and in libraries.

Correction: - that is <www.abebooks.com>. If you don't find it there search
'used books' through Google, but whatever you do, don't buy from Alibris. They
relist other people's books at 50% to 100% markup, plus shipping. If you order
from them, they then buy the book, and several weeks later, you get it.
Bob

Anthony Matonak

unread,
Dec 5, 2001, 10:15:57 AM12/5/01
to
"Calico Moon (Jeanine)" wrote:
>
> A million years ago the Mother Earth news had plans available for a
> solar heat grabber that is attached to your window.
>
> I have scoured my back copies with no luck.
>
> If any of you have these plans I would be interested in purchasing a
> copy of same.
... (snip incredibly large sig block) ...

Could this be what you are looking for?
http://www.jrwhipple.com/sr/solheater.html

Anthony

Bob Lewis

unread,
Dec 5, 2001, 2:06:43 PM12/5/01
to
The JR Whipple design looks very much like an early Mother Earth News
design... I would suggest that Bill Kreamer's Sol-Air design is only a
little more complicated to build, a little more expensive, but far more
effective. At present I can't find his site, but you can e-mail him
at kre...@mint.net
Bob

Bill Kreamer

unread,
Dec 6, 2001, 10:01:35 AM12/6/01
to
Hello all,

At night, an active solar collector loses virtually no energy, without
manual intervention. That's the essential difference between a solar
collector and a window. People with "passive" solar (lots of windows)
inevitably take an "active" role in reducing the nighttime losses of their
homes.

An active solar collector is, in effect, a large window with a virtual,
insulated window-plug that self-installs as the collector shuts down. To do
this, it must be designed so there's no nighttime anti-thermosyphoning, or
backdraft. See the instructions below.

Gain from a hot air solar collector is comparable to gain from a window, and
is directly proportional to glazed area. The gain occurs for 5-6 hours on
sunny days, during which time, both a window and a solar collector "leak"
some of the energy taken in. During collecting hours, there is a net gain.

But a window leaks energy 24 hours a day, while the solar collector leaks
energy only during collecting hours.

To produce "additional" energy, a solar collector can't be installed behind
the window glazing; it must be located so as not to obstruct the window;
that is, to one side of it.

--

Bill Kreamer
Sol-Air Company
129 Miller St.
Belfast, ME 04915

Tel 207-338-9513
Fax 603-853-9339
mailto:kre...@mint.net

-------

"N. Thornton" <big...@meeow.co.uk> wrote in message

news:a7076635.01120...@posting.google.com...

------
Hello,

Please let me know if you have any questions about any of the following
information. You can email me for a .pdf illustration of the collector
construction.

Bill Kreamer, President
Sol-Air Company
129 Miller St.
Belfast, ME 04915

tel 207-338-9513
fax 603-853-9339
mailto:kre...@mint.net
----

ADVANCED HOMEBUILT AIR-BASED
SOLAR COLLECTOR INSTRUCTIONS

OVERVIEW

INTRODUCTION

The instructions below are for a homebuilt version of Sol-Air Company's
air-based SHVC (Solar Heating and Ventilation Cooling) system (description
at bottom). Our commercial version differs from the homebuilt in having an
internal air-handler (the AutoVent automatic mode-switching control), and a
proprietary absorber material that has somewhat higher surface area and
selective properties.

Homebuilt Solar Collector Output

Like its commercial cousin, this homebuilt unit produces more energy for the
money by far than other forms of solar utilization, including PV and solar
DHW systems. The output for a 20 square foot unit is approximately 5,000,000
Btu per year, equal to approx. 50 gallons of heating oil (or 50 Therms of
natural gas). This output is produced primarily in the spring and fall, with
a decided dead spot in the middle of a cold winter.

Mounting

The collector is mounted vertically on the outside wall (the rule that tilt
= latitude is for another type - DHW collectors, which need year-round
input). The lower sun angle in winter reduces the performance penalty, and
the avoidance of summertime sun is an important factor in increasing system
life. Another advantage gained is ease of installation.

House connection

Air passes into and out of the collector through a manifold, which connects
it to the inside of the house. Instead of using the collector to replace a
window, plan to install your homebuilt collector with the manifold passing
through a hole in the wall, (you can install it beneath a window, or with
the manifold passing across the window sill of a slider-type of window).
That way, you will have two solar devices, the collector and the window.

WINDOW COMPARISON

At night, an active solar collector loses virtually no energy, without
manual intervention. That's the essential difference between a solar
collector and a window. People with "passive" solar (lots of windows)
inevitably take an "active" role in reducing the nighttime losses of their
homes.

An active solar collector is, in effect, a large window with a virtual,
insulated window-plug that self-installs as the collector shuts down. To do
this, it must be designed so there's no nighttime anti-thermosyphoning, or
backdraft. See the instructions below.

Gain from a hot air solar collector is comparable to gain from a window, and
is directly proportional to glazed area. The gain occurs for 5-6 hours on
sunny days, during which time, both a window and a solar collector "leak"
some of the energy taken in. During collecting hours, there is a net gain.

But a window leaks energy 24 hours a day, while the solar collector leaks
energy only during collecting hours.

To produce "additional" energy, a solar collector can't be installed behind
the window glazing; it must be located so as not to obstruct the window;
that is, to one side of it.

What's a Window Plug?

While a window has greater losses than an active collector, this can be
reduced if you manually insulate the window at night, with a "window plug"
that you make from 1" blue Styrofoam, edged with wood strips (3/4" x 1",
ripped from a 1x4). Each night, or right when you come home from work, you
plug your windows. When you put a window plug in, you feel warmer
immediately, because the radiant loss in the window direction stops, and the
surface of the styrofoam is much warmer. You can put window plugs behind a
couch or door during the day. Plug north windows all winter if you like; if
you do this, prevent condensation by caulking around the window plug with
re-usable "Mor-Tite" caulking. Use "Mor-Tite" on all your windows.

Build a Window Plug:

The monetary payback period for window plugs varies from instant (if you
have spare time and materials) to six months. In winter, they have an
immediate effect on room comfort.

To make one, tack together a rectangular frame of the 3/4" x 1" wood, to fit
the inside of your window frame. Use one nail at each corner, through the
end of one piece into the end grain of the next. Brace the frame with
diagonal pieces of wood while it's in the window. Remove it, lay it on top
of the Styrofoam on the floor, and mark inside the wood with a pointy marker
pen. Leave 1/16" clearance all the way around (1/8" overall). Use a very
sharp, very thin knife to cut the foam on the line.

Double 6" long fabric strips into loops to aid removal from the window. Slip
the foam into the frame, with a loop in the joint at each side near the top.
First use dots of hot glue to stabilize the foam inside the wood, then fill
the joint with sawdust-thickened wood glue. Cover one or both sides with
Contac shelf paper, muslin (attach with spray glue), wallpaper, etc.

For all-winter window plugs, prevent condensation by installing 3M V-seal on
the edges: Make the plugs 1/8" undersize (insert corrugated cardboard
underneath and on one side of the frame as you first fit it in the window
frame (see above). Sand and prime the wood edges with shellac before you
apply the V-seal. Use a sharp knife to cut the ends of the V-seal strips so
they meet nicely at the corners.

Now is the time to fix drafts around the window trim with "Mor-Tite".

COLLECTOR FEATURES

THE ABSORBER

The most important characteristic for an air-cooled absorber is super-high
surface area. For your home-built unit, a good solar absorber is 1" thick
furnace filter media, painted flat black; or you can use black polyester
felt and avoid the painting chore. This absorber material is mounted on a
suitable mounting rail, in a collector having reflective-foil interior
surfaces - a reflective cavity. Note: Because of high surface area, this
filament matrix absorber runs at a very low temperature with no outgassing.
There is literally no more outgassing than from a polyester wall-to-wall
carpet in a sunny room.

High Surface Area

Both furnace filter media and polyester felt present a surface area to the
airflow that is about 50 times the absorber's face area. This surface area
is higher, by an order of magnitude, than the surface area of conventional
metal absorbers, whether finned, rippled, dimpled, or screen type.

The sun shines on the fibers, which get very hot. As air passes through the
filament matrix, it has intimate contact with the fibers, and extremely good
turbulence. The turbulence reduces the thickness of the boundary layer of
air next to each fiber, increasing heat transfer to the air.

Low Cost Material

A virtual tripling of the heat transfer surface area is presented via a
conduction path length of one fiber diameter. Because this "tripled-area
path length" is extremely short, a non-metallic material may be used without
a significant performance penalty, resulting in a savings in material cost.

In the outer-surface, "inside out" heat exchange used by this "filament
matrix" type of absorber, sun-lit fibers transfer their heat directly at the
sites at which the heat is generated, or immediately adjacent to them. The
absorber's mass being finely divided and dispersed results in the length of
the internal heat-conducting path (through the fiber material from directly
sunlit fiber site to an adjacent shaded portion of the same fiber), is made
extremely short. In effect, a tripling of the available heat transfer
surface area is located a single fiber-diameter away from the primary sunlit
fiber site (heat travels each way along a fiber from the primary sunlit
site).

Material note: I have used both glass fiber and polyester fiber furnace
filter media as a solar collector absorber for 18 years without observing
significant material degradation. Polyester felt should do just as well. As
a pro-active precaution, observe the "Operation Caveat" stated below.

Low Cost Design

A liquid-cooled collector cannot take advantage of this type absorber
construction, which is very light. The low weight of the absorber produces a
cascade of weight and cost savings in the support structure of the
collector.

Absorber Efficiency

The absorber's high efficiency produces a low operating temperature. A
collector built to these specifications was tested at Western Michigan
University's Energy Learning Center - no longer operating, I understand -
using the ASHRAE 93-77 procedure, yielding a greater than 72% maximum
theoretical efficiency. This was the highest efficiency air collector they
ever tested; it bettered all liquid collectors but one, which it virtually
equaled. I know of no other non-concentrating air collector, Conserval's
SolarWall included, with better full-system efficiency.

If you use furnace filter media, you will want the kind that comes in roll
form so you can customize the size and shape of the collector. See a
Grainger industrial supply catalog, item 4WZ72 (roll, 36" W. x 90 ft.; 1"
thick); other widths are available there. You could go to an HVAC contractor
and ask them to cut you the lengths you need. Use hi-temp stove paint, and
spray it at a 45-degree angle (a "glancing" angle) from both sides, so
little of the paint passes through.

The Reflective Cavity Enhances the Absorber

The foil-faced inside surface of the collector is left reflective (not
painted black) so the black fibers do all the absorbing. Sunlight that
passes unabsorbed from the front direction is reflected back to the absorber
for another pass, doubling the effectiveness of the absorber.

--

MAKING THE SOLAR COLLECTOR

Build the collector case of 1" foil-faced isocyanurate (urethane)
foam-board. A good final case size is 46" x 64" (the case-back is 43-1/2" x
61-1/2"). The depth of the collector case is 6". With the back material
being 1" thick, this leaves 5" for air passages. The sides are 6" wide, and
they overlap the edges of the back.

Use urethane construction adhesive for all joints. On heat-exposed joints
like the case-side/case-back joint, protect the joint with a fillet of
silicone adhesive at the inside of the case. Apply the silicone adhesive
after the urethane adhesive has set (24 hours). Use spots of hot glue to
hold temporary right-angled pieces of foam-board at three places on each
side, to keep the sides straight and to hold them square to the back while
the urethane adhesive sets overnight,.

Both urethane adhesive and silicone adhesive use water (humidity) to
initiate curing; speed curing by spraying a tiny bit of plain water on the
edges of the seams after you put the pieces together.

To provide a surface that will hold the mounting bracket screws, glue 1/4"
plywood pieces, 6" wide and full length (short sides can overlap long sides,
or the reverse), on the sides only - no plywood is needed on the back. You
can also use luan underlayment plywood. It's slightly lighter, thinner and
cheaper, but it's a less "green" material. Glue the pieces on the four sides
of the case with a single 3"-wide wavy line of urethane adhesive.

There's no need to use 3/8" plywood - it just adds weight. Even though it
would give you a chance to screw-fasten the edge of the plastic glazing,
using screws produces not an even line of pressure, but a point pressure at
each screw. Since you're going to cover the case with an aluminum sheathing,
you should instead let the sheathing pull the glazing against the edge of
the case evenly all around the edge of the collector case.

Cut an 11-1/2" square hole, centered side-to-side, in the back wall of the
case; the upper edge of the hole is 3" from the outside top surface.

BEND THE ALUMINUM SHEATHING

To make the box weather resistant, you need an aluminum outside skin, or
sheathing. The dimensions are shown in the illustration. Make up the
sheathing pieces before you install the glazing, so you can install them
quickly immediately after, thus holding the glazing in place while the
silicone adhesive dries.

You can make the case sheathing in two ways. You could use pre-painted
aluminum coil-stock (house trim material, comes in 50-foot rolls). But, the
material is too thick to bend by hand. You should have the bends made by a
siding company on their "trim brake". Plain aluminum flashing is
satisfactory, just be sure to apply a car wax to the aluminum when you are
done, to protect it from unsightly corrosion. Aluminum flashing can be bent
by hand over the edge of a workbench, clamped under a piece of wood. All
the bent aluminum pieces needed can be gotten by bending 26" long pieces,
and overlapping them to get longer lengths. Hint: shorter pieces are much
easier to handle and bend than longer ones.

Make a clamping/backup block - a length of 1-1/32 " x 3-1/2" pine ripped
from a straight 2x4 - around which to bend the flashing. Set the backup
block on edge on top of the aluminum, at the edge of your worktable, and
apply a clamp at each end. Expose the aluminum past the edge of the table by
an amount equaling the dimension of the desired leg length.

Protect your working hand with a leather glove, and hold an old towel to
press against the aluminum. Bending the exposed edge downward, press and
slide your hand along the length of the bend. "Milk" it full length in this
fashion, then repeat, forming the bend a few degrees at a time.

The flow of air through the case is guided by a "C"-shaped baffle of
foil-faced foam, the exposed edges of which (including the edges that
support the underside of the glazing) you cap with 1/2" x 1" x 1-1/2"
aluminum cap-angle, shown in the illustration. Use the same backup block to
make the aluminum flashing cap-angles. Slightly over-bend the aluminum, as
specified - bend as far as you can with the material clamped, then unclamp
it and "milk" in some more bend by hand.

Last, make ten aluminum flashing mounting-rail pieces, 1"x1" x 4 feet long,
legs a 90 degree angle.

INSTALL THE "C"-SHAPED BAFFLE

The center leg of the "C" baffle runs across the 11-1/2" square hole in the
upper back wall of the case. The "C"-shaped baffle is glued with urethane
adhesive to the inside of the case, oriented with its center horizontal, at
the top, and with the two legs descending, parallel to each other. The upper
passage of the manifold is above the center leg of the "C", and the lower
passage is below. There is 6" vertical dimension of the hole below the
center leg of the "C", and 4-1/2" above. The distance between the descending
legs is 12".

Fillet all of the inside collector joints, including all around the "C"
baffle, with silicone adhesive. Cap the baffle with the aluminum cap-angle
you bent up earlier using a 3/8" bead of silicone inside the angle.

INSTALL THE ABSORBER MOUNTING-RAILS

The absorber sits on mounting-rails aligned on a diagonal to the air flow.
Air enters the collector between the absorber and the glazing. As it moves
through the collector toward the outlet, the diagonal absorber placement
forces air to pass through the absorber to the back side, away from the
glazing. The diagonal progression starts with the absorber near to the back
wall at the inlet, and moves near to the glazing at the outlet; the
progression continues all along the air flow path. This keeps the hottest
air away from the glazing, reduces conductive heat loss, and increases
efficiency.

Use the 1"x1" angles of aluminum flashing that you bent up earlier as
mounting-rails. Install each mounting-rail so the leg touching the collector
is oriented toward the back wall. Use dots of hot glue a foot apart to hold
the mounting-rails in place temporarily; then run a continuous fillet of
silicone adhesive along the joint between the angle and the collector wall.

INSTALL THE MOUNTING-RAILS

Install horizontal mounting-rails at the top and bottom inside surfaces of
the collector. Use two or your pre-bent angles pieces, overlapped by an
inch, to make up the needed length. Stop the rails 3/8" short of the
adjoining surfaces. The top mounting-rail has its absorber-mounting-surface
spaced 1-1/2" from the glazing plane. The bottom mounting-rail has its
absorber-mounting-surface spaced 2" from the back wall (3" from the glazing
plane).

Install diagonal rails beginning at the inside of each "C" leg starting
below the fan; at this end, the absorber-mounting-surface is spaced 1/2"
from the back wall of the collector. The rails run in a straight line to
overlap the rail at the bottom of the collector; that is, they run at a
slight angle away from the back wall down each "C" leg, continuing past the
bottoms of the "C" legs to overlap the bottom rail. Snip a small piece from
the back leg of the angles so they can overlap the bottom rail.

Moving to the side bays, install diagonal mounting rails at the sides of
each bay, so the rails make a continuous straight line from the bottom rail
to the top rail. Again, snip a small piece from the back leg of the angles
so they can overlap the bottom and top rails.

Where the four central rails of the collector cross open space, snip the
back leg of each rail near the "C" baffle and fold the rail flat. This
allows air to travel unimpeded between the center bay and the side bays.

INSTALL THE ABSORBERS

With the exception of the fan/intake shroud area, the entire face of the
collector is covered with absorber mounted on rails. In preparation for
installing the absorber, cut the pieces you will need to size, and paint
them from both sides with hi-temp stove paint from a spray can, holding it
at a 45 degree angle to the face of the. Work quickly, covering first the
back, then the front; favor the front with the most paint. Use nearly the
entire spray can, leaving enough to paint the fan shroud. At the very end,
just before you put on the glazing, use the last of the paint to touch up
where needed.

Working one foot at a time, glue the absorber to the mounting-rails in a
continuous bead of silicone adhesive, again using occasional dots of hot
glue as a temporary aid.

INSTALL THE FAN

Install your collector fan (Grainger, 4WT48 70 cfm, or 4WT47 105 cfm) and a
pre-set snap-disc cooling thermostat (Grainger 2E245, close at 110 degF,
open at 90 degF) in a shroud of aluminum flashing or house trim. Make a
one-piece fan-and-solar-thermostat inlet shroud, or you can use a two-piece
shroud. One piece, to mount the fan, is an 11-7/8" x 6" pan with 1" flanges
on top and bottom (make from 11-7/8" x 8" material); it has a 4-3/4" hole at
its center and a 3/8" hole at one side to pass the thermostat leads out from
the collector. Mount the fan over the hole with 1/8" x 1/4" pop rivets and a
fillet of silicone adhesive, and bond the assembly in place with silicone
adhesive vertically in the intake, at the back wall of the collector. Make
sure the fan's air-direction arrow points into the collector.

The other shroud piece is also mounted with silicone adhesive. It has a 1"
horizontal leg, a 4" 45 degree surface to mount the thermostat facing the
sun and to redirect the incoming air downward, and a descending 3" leg.
Mount the thermostat through a hole the size of a quarter, and fasten it
with pop rivets. Bond the thermostat shroud in place so the vertical leg is
spaced 1/2" away from the plane of the glazing. Pass the thermostat leads
through the 3/8" hole in the fan mounting plate. Wire the fan and the
thermostat in series - tie one lead from the fan to one lead from the
thermostat with a #14 wiring nut, and finish with an 8" length of electrical
tape. Seal the thermostat wire hole with silicone adhesive. The remaining
unattached leads, one from the fan and one from the thermostat, will be
wired to the power cord leads at final installation.

TOUCH-UP

Use the rest of your spray paint to paint the inlet shroud (paint the nose
of the thermostat) and touch up the absorber.

INSTALL THE GLAZING

The glazing can be Plexiglas (acrylic), which does well in this application
because of the vertical angle and the efficient (low) temperature at which
this collector runs, or another material of your choice (Kalwall).
Polycarbonate (TwinWall, etc.) is strong, but may yellow. Cut the glazing to
size to match the inside line of the plywood. Install the glazing with 1/8"
pop rivets (1/4" grip range), spaced every 8" along the baffles.

Install pop rivets through the glazing every 8" along the "C" baffle. Put
four rivets across the center of the "C" baffle.

Lift the glazing edge slightly and put a 5/16" bead of silicone adhesive
around the collector sides where the glazing will sit. Place the silicone
adhesive bead near the inside edge of the surface, so that as you allow the
glazing to rest on it, the adhesive squeeze-out just reaches the inside of
the collector.

INSTALL THE ALUMINUM SHEATHING

Press the aluminum sheathing in place using an aid made from two 2-foot-long
1 x 1-1/2's glued together to make a 90 degree angle. As you do, install
1/8" pop rivets through the sheathing into the plywood, all around the sides
of the collector, located 1" from the front edge, and every 8".

Install the sheathing angle all around the rear of the collector with 1/8"
pop rivets into the plywood spaced, located 1" from the rear edge, every 8".

Working on each side on turn, tip the collector up on the side on a flat
work table, to help ensure the sheathing edge is straight and cannot slip
toward the side. Install 1/8" pop rivets, through the bend line where the
sheathing touches the glazing (drill these holes through both sheathing and
glazing). Rivet around the collector face on the contact line using a 12"
spacing.

DRESS AND FILL THE GLAZING JOINT

Use a gentle leather-glove touch to adjust the gap where the edge of the
aluminum sheathing "returns" away from the glazing. The gap should be at
least 1/4". Completely fill the gap with silicone, and finish it the joint
with a spoon. Allow the fillet to extend 1/4" out onto the face of the
glazing. Don't try to clean up until the silicone cures.

This seal design is tough and won't be broken by shock or expansion from
temperature change.

THE MANIFOLD

The collector connects to the house via a manifold box made using the same
construction materials and gluing method you used for the case - a urethane
foam-board box with an outer layer of plywood around the sides. It also has
a sheathing of aluminum flashing, made from a 9" x 1-1/2" angle, 60" long
(this allows an overlap). The 14" square, 9" long, two-way, over-and-under
manifold connects to the house through the wall or across the window sill.
You can use plywood on just the top and bottom, or on all four sides of the
manifold. The manifold is divided by a foam-board "center divider" into a
lower intake and an upper exhaust passage (back to the house). The lower
passage is 6" high, the top is 4-1/2" high.

Cut an 11-1/2" square piece of furnace filter media to use for an
inlet/outlet filter. On the upper surface inside the upper passage, 1" away
from the front face, install an 11" length of 1" x 1" flashing angle. Use
hot glue dots and silicone adhesive. Face the angle legs away from the front
face. This will act as a stop and support for the edge of the inlet/outlet
filter. Do the same at the lower surface inside the lower passage. The
filter will span the center divider of the manifold, and rest against the 1"
x 1" stops.

Install a Grainger 2W050 three-wire power cord up through a 3/8" hole in the
bottom front edge of the manifold; make an overhand knot for a strain
relief. Put a ring terminal on the green ground wire. When you make the
final installation, fasten the ring terminal to the fan shroud with a 3/16"
aluminum pop rivet. Note: You could install an additional room temperature
thermostat (open on temperature rise) in the inlet to disable the fan on
rising room temperature; this would partially limit warm weather output. But
the unit will still thermosyphon slowly. To fully prevent the unit from
heating in summer, without damaging it, you will have cover it with a cloth
or plywood cover. Do not close or stop up the manifold openings without also
covering the collector, as this would cause very high collector temperatures
and consequent material damage.

The grilles for the manifold should be split, to eliminate heat cross-over.
Don't choose moveable-louver grilles. You could use perforated metal. The
best and cheapest pre-made grilles are white painted steel, available from
Hart and Cooley through your local HVAC supplier. Order one
#672-steel-white, 12 x 4 for the upper air passage, and one
#672-steel-white, 12 x 6 for the lower passage. These are approximately
13-3/4" long, and 5-3/4" high for the 12 x 4, 7-3/4" high for the 12 x 6.

There are two mounting holes in the grilles (one at each side). Use urethane
adhesive to glue a block of wood into the foam-board to accept a screw at
each mounting hole location. Install the grilles with the bottom grille's
louvers angled down, and the top grille's louvers angled up, to help prevent
air from crossing over from outlet to inlet (short-circuiting). The hot
outlet air tends to segregate itself by rising away.

INSTALLATION

PLAN THE INSTALLATION

My preferred installation method is to cut a 14-3/8" square hole through the
wall between studs (assuming a 14" square manifold). Or, if you choose, a
sliding window installation is an option. Just pre-mount the manifold to the
collector the day before with urethane adhesive. Give the adhesive a full 24
hours to cure. Prop the collector in place with the manifold coming across
the window sill. If you have a storm sash, seal that one first. Shut the
sash on the manifold and block off the gaps with 1" urethane foam-board -
the same foam-board used to make the collector. Trim the foam-board edges
with aluminum foil tape. Next do the same to the inside sash. Caulk only the
joints at the bottom and sides of the foam-board. Use peel-and-stick foam
strips on the underside of the sliding sashes so you can open them when
needed. Install a security catch on the inside sash if desired.

Preparation

In preparation for installation, make (4) brackets of 1/8" x 3/4" flat
aluminum bar, 9" long , bent to give a 6" and a 3" leg. Use a 3/16" drill
for #10 stainless pan head screws. Drill (3) holes in the 6" leg, (2) holes
in the 3" leg. Put (3) #10 x 3/4" stainless screws through the 6" leg into
the collector, and (2) #10 x 1-1/2" stainless screws through the 3" leg into
the building. Use one bracket near each corner of the collector.

BEGIN THE INSTALLATION

Wall installation:

Make a small hole in the center of where you think you'd like the hole to
be. Probe with a coat hanger to locate the studs. Measure the manifold and
mark lines for a hole 3/8" bigger than the manifold dimensions. Cut the
inside wall board with a utility knife. Stuff the insulation from the hole
into the wall cavity. Square from the edges of the inside hole over to the
outside wall, and drill holes at the corners to the outside. From the
outside mark the lines, check the dimensions, and make them plumb and
square. Use a saw to cut the hole.

Sliding Window installation:

Pre-mount the manifold to the collector the day before with urethane
adhesive. Give the adhesive a full 24 hours to cure. Prop the collector in
place with the manifold coming across the window sill. If you have a storm
sash, seal that one first. Shut the sash on the manifold and block off the
gaps with 1" urethane foam-board - the same foam-board used to make the
collector. Trim the foam-board edges with aluminum foil tape. Next do the
same to the inside sash. Caulk only the joints at the bottom and sides of
the foam-board. Use peel-and-stick foam strips on the underside of the
sliding sashes so you can open them when needed. Install a security catch
on the inside sash if desired.

Flash the Hole

Next, line the hole with a piece of aluminum flashing. This will be flush
with the inside wall surface, with 3" wide ears bent to sit against the
outside wall. To make this, cut a piece of flashing 60" long, and 3" wider
than the wall thickness. Make a 90 degree, 3" wide bend down the length of
the piece. Make cuts through the 3" leg, to allow you to wrap it around the
outside of your 14" square manifold, making 90 degree bends at the four
manifold corners. Set the manifold aside to attach to the collector later,
from inside the house. Staple the pre-bent flashing into place in the hole,
putting some staples inside the hole and at least four in each outside ear.
Caulk under the ears (don't neglect the corners) with silicone adhesive.

Pre-Mount the upper Brackets

Mount the upper two mounting brackets to the collector (use (3) #10 x 3/4"
stainless screws). Take care to locate the brackets so the collector will be
spaced about 9/16" away from the wall (or from the clapboard bottom edges,
if you have clapboards; and locate the brackets so they fall just under a
clapboard edge).

Before you place the collector against the wall, press sticky-back foam seal
strips (3/16" thick x 1-1/2" wide, the type used to mount camper caps onto
pickup trucks) to the back of the collector around the 11-1/2" square
manifold hole. Space the foam strips 1-3/4" away from the hole edge. Build
up three layers of the strips, so the seal is 9/16" thick.

Prop the collector in position

Now use short pieces of 2x6, on edge, as braces under the collector to raise
it to the right height on the wall (so the foam seal rests on the flashing
ears). Use a long 2x4 as a brace to keep the top brackets of the collector
against the house. Use a level to get the collector plumb. Now take the
manifold inside the house. To check whether the collector is aligned with
the hole, insert the manifold into the hole and check that the center
divider lines up with the "C" baffle in the collector case. Readjust
everything until it's plumb and aligned.

Outside, fasten the upper collector brackets first, then install the lower
ones (keep the collector vertical, viewed from both ways. From the inside,
with the manifold removed, use silicone adhesive to caulk around the
perimeter of the hole against the foam seal. Completely fill the space
between the collector and the flashing.

Install the Manifold

To install the manifold, lay a generous 1/2" bead of urethane adhesive
around the manifold rear edges and across the center divider. Place it in
the hole, and press it onto the collector. It should stay there by itself,
or you can wedge it in position to cure overnight. You can immediately caulk
the gap around the manifold at the inside wall with siliconized latex caulk.
For a finished look, trim with quarter-round or picture frame molding.

Operation Caveat

As stated earlier, to fully stop the unit from thermosyphoning in summer
without damaging the unit (due to high stagnation temperatures), you must
cover it, not simply close or stop up the manifold openings. Do not close or
stop up the manifold openings without covering the collector, as this will
cause very high temperature and material damage.

The worst of the "new collector" smell is gone in a few hours (silicone
curing smells like vinegar) and will disappear in a day or two.

To Make Larger Arrays

In scaling up, keep these points in mind:

1. The geometry shown in the accompanying illustration permits daytime
thermosyphoning, and discourages nighttime thermosyphoning (the descending
and rising legs of the flow circuit are both at outside temperature at
night, and are of nearly equal height). If you change to a different flow
layout, you may need an anti-backdraft damper.

A manifolded array would use collectors 4 feet wide by any height, and
divided into left and right (rising and descending) halves by a vertical
baffle, with the halves interconnected at top or bottom by a gap in the
baffle, with the absorber mounted on rails in each half, on one long
diagonal from inlet to outlet.

2. With more than 25 square feet (one good-size collector per room), room
overheating becomes a concern in warm/hot weather. You will want large size,
automatic or manual collector vents (without these you will need to cover
the collectors in summer). In addition to collector vents (top and bottom),
you may still have to cover the outlets manually in the hottest weather, and
make sure the collector temperatures do not climb too high.

(This is why I invented the AutoVent control. This is what makes an SHVC
(Solar Heating and Ventilation Cooling) system. It integrates two three-way
valves (one at the inlet, one at the outlet), and four ports (an
inlet/outlet pair at both the interior and the exterior) into a drop-in
control module.)

3. A large array manifolded with a single fan should be segmented into areas
(separate collectors) with a parallel-flow circuit. You might need to
restrict the higher-flow collectors to get the array balanced.

You could use "in-at-the-bottom, out-at-the-bottom" collectors manifolded in
parallel. These could be served by a split over-and-under manifold duct
located at floor level on the inside wall, that might not be too intrusive.
It might be three to four inches thick out from the wall, by two feet in
height. The bottom 12 inches would be the intake manifold, with an intake
grille located at one side of the room; the lower part would be divided from
the top 12 inches, the outlet manifold, with a grille at the other side of
the room. Or, there could be small outlet grilles located all along the top
of the outlet duct and small intake grilles located all along the intake
duct.

In this scheme, the entry and exit connections to the collector are all
located low in the collector. This arrangement tends to thermosyphon at
night, in either direction unpredictably; it will need a positive manual
damper, or a timed electro-mechanical damper, that prevents nighttime flow
in either direction.

An alternative scheme that needs no damper is to place the over-and-under
manifold duct near the ceiling, serving "in-at-the-top, out-at-the-top"
collectors manifolded in parallel. There would be an auxiliary inlet duct
connecting to the inlet half of the split over-and-under manifold. It would
descend to the floor at one side of the room. there would be an auxiliary
outlet duct connecting to the outlet half of the manifold, descending to the
floor at the other side of the room (i.e. one descending duct at the left
side and one descending duct at the right side of the room, at the corners
against the outside wall). The reason for the descending ducts inside the
room is to receive the coolest inlet air and distribute heated air low in
the room.

In this scheme, the entry and exit connections to the collector are located
high in the collector. So, the descending and rising outside legs of the
flow circuit are both at outside temperature at night, the inside descending
and rising legs are at inside temperature, and all are of nearly equal
height, so you don't need any damper.

HAPPY BUILDING!

Bill Kreamer, President

Sol-Air Company


SOL-AIR COMPANY'S PRODUCT - THE SHVC

Sol-Air Company makes the SHVC solar system, the world's only modular solar
comfort system. In a single wall-mounted module, it provides space-heating
in cold weather, ventilation cooling in warm weather, and both cool-air
conservation and system safety in hot weather - all done automatically. The
SHVC system offers a realistic payback and a 20-year+ working life. Its
year-round capability distinguishes it from the seasonal "air panel" or "hot
air collector". Its patented control shifts automatically between four
operating modes, hands-off, year-round. The system is packaged for easy
installation.

As the room temperature rises in warm weather, Sol-Air's AutoVent(tm)
adaptive air handling control initiates room ventilation. In hot weather,
the system acts conservatively by sealing the house, power-venting the
collector with outside air to prevent collector damage. It thus conserves
cool inside air, and even allows conventional A/C to operate normally. You
don't cover the system manually to prevent overheating, or uncover it to
resume heating. The system returns to the solar heating mode automatically
as the weather changes. Our breakthrough Transorber(tm) solar absorber gives
the system a maximum efficiency greater than 72% - the SHVC solar system
provides energy, comfort and safety, automatically and efficiently, all
year!

Contact us!

Bill Kreamer, President

Sol-Air Company
129 Miller St.
Belfast, Maine, U.S.A. 04915


Tel 207-338-9513
Fax 208-978-7839
Email kre...@mint.net


jw&a

unread,
Dec 6, 2001, 12:45:10 PM12/6/01
to

"Bill Kreamer" <kre...@mint.net> wrote in message
news:jLLP7.155$zA5.1...@news1.news.adelphia.net...
> Hello all,

> What's a Window Plug?
>
> While a window has greater losses than an active collector, this can be
> reduced if you manually insulate the window at night, with a "window plug"
> that you make from 1" blue Styrofoam, edged with wood strips (3/4" x 1",

there is lot's of cool info in the post (which i printed out to take home
and study), but i wanted to point out that styrofoam isn't supposed to be
used indoors without a fire rated cover. it burns very hot and very fast,
especially when it's in a vertical position. last winter i made an all
winter window cover by putting a piece of foam in the window and screwing a
sheet of plywood over it. it worked great. i've been trying to figgure out a
way to use foam insulation to plug windows but most of my ideas are either
too difficult to make, or too difficult to use. comfort is good, but death
sucks.

bob
south carolina

Bill Kreamer

unread,
Dec 6, 2001, 9:51:10 PM12/6/01
to
Hmmm. I hear you loud and clear. There's a goodly list of household danger
items in that category (curtains near candles, towels near electric
heaters). We must be careful with all such, especially with any normally
curious children in the home. I usually put a layer of printed muslin or
burlap over the styrofoam for appearance. I don't know if that reduces the
chances of ignition. Please all take care, and thank you.

Bill Kreamer
Sol-Air Company
129 Miller St.
Belfast, ME 04915

"jw&a" <jw...@usenetserver.com> wrote in message
news:U0OP7.110737$8n4.7...@e3500-atl1.usenetserver.com...

Ron Purvis

unread,
Dec 7, 2001, 12:30:03 AM12/7/01
to
Do you have any further info on this mirror. This is the 3rd time I have
asked after you mentioned it. I am really interested in what it looks like
and how it works.

Ron

N. Thornton <big...@meeow.co.uk> wrote in message
news:a7076635.01120...@posting.google.com...

Anthony Matonak

unread,
Dec 7, 2001, 7:40:45 AM12/7/01
to
Ron Purvis wrote:
...

> N. Thornton <big...@meeow.co.uk> wrote in message
> > It is a near horizontal mirror outside the window at sill level. It
> > provides a little free winter heat, not a great deal, and pays for
> > itself many times over.
...

> Do you have any further info on this mirror. This is the 3rd time I have
> asked after you mentioned it. I am really interested in what it looks like
> and how it works.
...

I'm not the original author but I could hazard a few guesses.

a) Since the author is 'N. Thornton' and they refer to it as a
'Thornton mirror' I would assume that it's not a description in
common use outside of their family.

b) Sounds like they are using a large mirror under a south facing
window to reflect sunlight through it and increase the amount of
light and heat they collect.

Assuming (b) then all you need to do is buy any kind of reflective,
mirror-like, stuff and place it under your south facing windows.
Generally, the more the mirror extends away from the house (if
it's angled right) the more sunlight it'll reflect into the window.
The more the mirror extends past the window east and west the longer
during the day it'll reflect into the window. With the help of a
sun angle chart for your location and some graph paper you should be
able to figure out the best size and angles. It should be shadowed
or covered in the summer months to decrease heat gain through the
windows. http://solardat.uoregon.edu/SunChartProgram.html

Windows not facing south would require heliostats.

Anthony

N. Thornton

unread,
Dec 8, 2001, 7:53:51 AM12/8/01
to
N. Thornton wrote:

> > > It is a near horizontal mirror outside the window at sill level. It
> > > provides a little free winter heat, not a great deal, and pays for
> > > itself many times over.

Ron Purvis wrote:

> > Do you have any further info on this mirror. This is the 3rd time I have
> > asked after you mentioned it. I am really interested in what it looks like
> > and how it works.

Anthony Matonak <res0...@gte.net> wrote

> I'm not the original author but I could hazard a few guesses.
>
> a) Since the author is 'N. Thornton' and they refer to it as a
> 'Thornton mirror' I would assume that it's not a description in
> common use outside of their family.
>
> b) Sounds like they are using a large mirror under a south facing
> window to reflect sunlight through it and increase the amount of
> light and heat they collect.
>
> Assuming (b) then all you need to do is buy any kind of reflective,
> mirror-like, stuff and place it under your south facing windows.
> Generally, the more the mirror extends away from the house (if
> it's angled right) the more sunlight it'll reflect into the window.
> The more the mirror extends past the window east and west the longer
> during the day it'll reflect into the window. With the help of a
> sun angle chart for your location and some graph paper you should be
> able to figure out the best size and angles. It should be shadowed
> or covered in the summer months to decrease heat gain through the
> windows. http://solardat.uoregon.edu/SunChartProgram.html

Ah, zis Inspecteur Anthony is clever, non? (Add Clouseau accent)

I did say I would post info at some point, just too busy.

As said, it is a near horizontal mirror which reflectrs in extra heat
and light through the year. It pays back its cost several times over,
though the size of the payback is unremarkable. The light gain is as
important as the heat gain. It makes a big improvement to the feel of
a room.

When these mirros are built into the design of the house they permit
the use of smaller eindows, which further improves heat gain. They are
yet another small beneficial concept in energy efficient building
technology.

The name Thornton mirror is used elsewhere, though not very well
known.

You can not use any kind of reflective mirror like stuff. Many types
of reflectors produce unpleasant glare. Glass mirror is the one to
use. In some situations plastic mirror may be preferred, but does not
last so well. USed glass mirrors pay back well, new ones dont have
especially good payback. Reflective surface mustr be p[rotected
against corrosion with durable paint.

The mirror is not shaded in summer. This is not satisfactory. The use
of a white blind or thin curtain is recommended on the window. This
not only cancels the mirror's heating but redces direct sun heating
too, resulting in a cooler house. A very thin white curtain, like a
thin sheet, will let lots of light in.

Randy Cox

unread,
Dec 8, 2001, 1:16:43 PM12/8/01
to
Hey guys, I make one of these that uses a piece of NiTi ("memory wire") to
open a damper when the collector gets hot, then closes it when it cools
down.

Mine are 33" wide (the CLEAR opening required of the window it's placed in)
and extend about 40" below the window sill...

These are really easy to make...I have some CAD drawings and a parts list,
but no assembly instructions yet....I think I can turn the drawings into
JPEG or GIF's....

..contact me if anybody wants more info...


"Calico Moon (Jeanine)" <cal...@elemeno-p.com> wrote in message
news:3c085dc5...@news.CIS.DFN.DE...

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