Mounts to your outside wall and heats a
standard size room when the sun is out.
Kit Includes: 2' x 5' x 4" deep .060"
mill finish aluminum collector box 2' x 5' .019" black flat
aluminum absorber plate 10mm thick x 2' x 5' Sunlite
HP® collector cover 1 roll of pressure sensitive glazing
tape Fan, thermostat and backdraft damper Complete assembly
You assemble the components or order your
airheater factory assembled. The sides and back of the collector box
should be insulated and can be finished to match your house. Use
Build your own Solar Airheater using our
SunLite® HP Solar Glazing and
readily available materials and save money on your heating costs. A
typical 4' x 8' collector can provide 25 to 50% of the energy needed
to heat a 400 to 800 square foot space depending on climate and
This Axial fan is
great for solar airheaters. 124 CFM, Voltage 115 AC, 60/50 Hz,
Single Phase, Amps 0.25, Watts 21, Fan RPM 2750, 47 dBA,
Height 4 11/16 In, Width 4 11/16 In, Depth 1 1/2 In, Mounting
Holes O. C. 4 1/8 In, Vertical or Horizontal Mounting
Enclosed high quality thermostat has
liberal contacts and push on terminal clips. Holes provided
for mounting screws. Factory set for 110° F on, 90° off. Rated
5 amps at 115V.
Duct Damper Prevents Back Drafts
Backdraft Damper, In-line Type, Fits
Duct Dia. 6 In, Galvanized Steel, Includes Spring Loaded
Lightweight Aluminum Damper Blade
7" Diameter Air Heater Collar
Galvanized Steel Snap-Lock Duct
Fitting 7" Diameter Self-Sealing Collar. Attach to back of
airheater to penetrate wall or
Thermalox Selective Surface Spray
Thermalox Solar Collector Coating is a Silicone based
heat-resistant selective paint designed for use on metal
surfaces of solar collector panels - will withstand up
to 1000° F. Thurmalox will function with maximum
efficiency (absorptivity .96, emissivity .52) when
applied 0.5 mils thick. Coverage 25 sq. ft. the
coating resists out-gassing (a major cause of internal
fogging of collector covers) up to 400° F. Made with
heat stable pigments, the coating will withstand
repeated thermal cyclings and temperatures as high
as 1000° F. Thermalox is unaffected by humidity,
and will not peel or discolor. 13 oz. aerosol can.
primer not necessary for copper or
Solar Airheater Box Only
.060" thick aluminum box 24" wide
x 60" long x 4" deep. 4" diameter holes in back for
fan and damper. Comes with Sunlite Airheater Kit
above. For easy construction of your solar
Coil Stock Absorber #05070
thick aluminum absorber sheet. Great for do-it-yourself
solar hot air collectors. 24" wide and sold by the
linear foot. Black one side, white on the other side.
Minimum order 8 linear feet.
$3.50 per lin
A Passive Solar
Space Heater for Home Use A perfect
idea for the do-it-yourselfer!
Prepared by the
Public Relations Department Worcester Polytechnic
Institute Worcester, Massachusetts 01609
The following describes construction of a solar
heater that uses free energy from the sun to provide part of
the winter heating requirements of homes to which this heater is
adaptable. This design is based on a heater built by professor Bruce
McQuarrie of Worcester Polytechnic Institute at his home in Auburn,
Massachusetts. He estimates that he saved in only two years the cost
of the materials to build it.
How It Works
Sun shining through the solar panels heats the air
inside the triangular shaped box. As the air inside is heated, it
rises to the top of the box and passes into the house through the
open window or opening on the first floor. As the heated air moves
into the house, it is replaced by cool air moving into the box
through the open basement window. There are no moving parts. Leaving
the cellar door ajar may aid circulation. A small fan may aid air
flow in the house. Some experimentation may be needed.
Is This Solar Collector For You
The home must have a south facing (or nearly south facing)
outside wall with both basement and first floor windows.
There must be unobstructed sunlight on the heater from January
to March. If other buildings interfere, this device cannot work.
Tall leafy trees which shade the home in summer will not cause
much loss of sunlight in winter. However, evergreen tress would be
a problem. If obstructing evergreens can be trimmed or removed,
you can use this heater. (see
The solar heater consists of a floor and two
triangular end walls of plywood nailed to both sides of 2 x 4
studding on 16-inch centers. The space between contains insulation.
The collector surface, through which the sun shines, consists of two
layers of solar sheeting such as Sunlite® HP fiberglass sheeting or
Sunlite® HP prefab panels. An access door on one end wall permits
entry for maintenance, such as repainting, caulking, etc.
A plywood lid folds over the face of the heater in
warm weather. When open, this lid helps reflect the winter sun into
Figures I and II illustrate the alternative
methods of building this passive solar heater. Exact details and
measurements are intentionally not shown. The angle of the face of
the heat collector varies with the latitude in which it is to be
used, so construction measurements will vary somewhat from one area
A professional carpenter or an experienced
do-it-yourself home handyman should have no trouble adapting these
general guidelines into an actual design for a specific
Step 1. Determine the latitude of the home to
the nearest even degree. Most highway maps indicate latitude. As a
general rule, the slope of the collector face with the horizontal
will be an angle equal to the latitude plus 15°. (see inset in Fig. I) This chart is provided for
Step 2. Determine where the heater will be
placed on the south facing wall. Fig.I illustrates an installation which does not
interfere with normal use of the first floor window. Fig. II
simplifies construction but prevents normal use of window with
The method in Fig.I requires cutting an opening through the wall
under the window to admit the heated air.
If it is preferable not to cut through the wall, a
detachable plywood "chimney" (which can be removed after the heating
season) may be used to convey the heated air into the house through
the lower half of the window. This "chimney" should be insulated and
sealed around all edges to minimize heat loss.
Step 3. Determine exact position of sloping
studs which will support the translucent fiberglass sheet or panel
before ordering them. On two concrete blocks, set a 2 x 4 on edge to
simulate the position of the level floor. From the height on the
outside wall of the house which will mark the upper edge of the
heater, stretch a piece of string to form the desired slope angle
with the base. (Point A to point B in Fig.I ). The length of the string will determine
the length of the sloping studs and the translucent sheets will
determine one of the base dimensions. The Fiberglass sheets are
available in pre-packaged rolls, 4 feet wide by 8, 10, 25, and 50
foot lengths. One 50' roll should be enough to make a heater 12 feet
long with a sloping face of 8 feet, such as in Fig.I
To avoid waste, consider standard dimensions in
determining actual construction details. 2 x 4 studs come in 8'
lengths. Plywood or particle board sheets come in 4' x 8' feet
sheets (check your local supplier for other standard sizes). Roll
insulation is designed to fit between studs on 16" centers.
Step 4. If you decide to cut an opening under
the window rather than use a "chimney", do this next. The opening
should have about the same area as the basement window. Finish off
the opening neatly, inside and out. Provide a cover on the inside to
prevent cold air leakage at night or during prolonged
Step 5. Construct base of 3/8" plywood or
particle board made for outdoor use. Select inexpensive grades. Nail
plywood to 2 x 4's on 16" centers and then turn floor over and level
it on concrete blocks, shimming until level and evenly supported.
Install roll insulation and nail on plywood flooring. Nail vertical
studs to side of house to support back wall of plywood (not shown in
Fig.I or Fig.II ). Insulate particularly well along cellar
wall to prevent heat loss. Nail on plywood back wall.
Step 6. Install sloping 2 x 4 supports. Space
them to the exact width of the fiberglass sheets to eliminate
cutting the sheets. Thus, the length of the base will be 12' plus
the thickness of four 2 x 4's. Nail in end wall studding, providing
for an access door in one end. Nail outside plywood panel to
studding. Install roll insulation between studs. Nail on inside
Step 7. Install flashing under the shingles or
clapboard on house wall at top of heater to prevent water leaks.
Step 8. Nail 1" x 1" strips to lower edge of
sloping studs to support inner fiberglass panels. Install panels and
caulk the edges with silicone sealant. (see Fig. III) . If you use the chimney method,
build and install it before installing fiberglass sheets. Side may
be of plywood similar to sidewall construction (with insulation
between). The top surface may be made of fiberglass sheets separated
by an air space. These sheets will be bend into a curve. (see Fig.IV)
Step 9. Nail a second set of strips to sloping
2 x 4's to support outer fiberglass panel so that panel is flush
with upper surface. Caulk edges.
Step 10. Caulk flashing at upper edge of panels
to prevent leakage. Nail 1" x 3" strips along edges of loping 3 x
4's to finish off the sloping surface.
Step 11. Make plywood cover to fit between 1"
x 3" strips when closed over the heater in summer. Install hinges so
it can be opened for winter heating season.
Step 12. Make access door and install. This
should be same construction as end walls with insulation between
Step 13. Paint inside plywood surfaces with
flat black to aid in absorbing heat. Do not paint house wall. Paint
inner cover surface white to reflect sunlight. Paint outside to
match the house color for appearance and protection.
To eliminate moisture from condensation between the
fiberglass sheets, drill small holes at the bottom of each section
Roll insulation should be R-11 foil faced fiberglass
insulation. Install with foil towards inside of heater.
Since fiberglass sheets are flexible, install some
type of cross supports between the 2 x 4's. Wooden dowels or cross
strips of wood may be used. Place them at the one-third and
two-thirds points on the sloping 2 x 4's.
Clearance above ground is important to prevent the
wood from rotting. Concrete blocks provide about the right
Clean the surface of the fiberglass sheets as needed.
Dirt obstructs the light and cuts down heater efficiency. Plain
water is usually sufficient. Remove snow in winter.
Heater works best when basement window is at one end
of heater and first floor opening is at opposite end since air must
travel further and stay in the heater longer before entering the
house. If first floor opening is directly above the basement window,
experiment with baffles. (see
Extra heat holding capacity may be gained by
installing heat absorbing elements inside the heater. Black painted
aluminum cans or metal sheets fastened together may help. This is a
chance for you to experiment.