Washington D. C. environs

(cont'd)

(Thomason Solar House 6, cont'd)

65

WAS 1/17/75

Collector: 960 ft2 gross, 800 ft2 net. Dimensions: 60 ft x 16 ft.
Consists of 15 panels, each 4 ft x 16 ft, on 45° roof. Panels were
assembled elsewhere, then installed. Collector is of trickling water type,
with water trickling down 1-in.-wide valleys, 2.7 in. apart on centers
(approx. -in. deep) in corrugated aluminum sheets (0.017 in. thick)
that have black coatings. Collector is single glazed. Most of it is
glazed with 48 in. x 24 in. x 1/16 in. single-strength glass panes; lowest
4-ft-wide band is of double strength glass, to withstand greater snow load.
Panes are -in. from aluminum sheet. Panes are mounted in aluminum frames
which rest on the aluminum sheet. Filtered water (with no inhibitor or
antifreeze) is fed via a horizontal distribution pipe (3/4 in. dia. copper)
and a set of junior pipes (3/8 in. dia.; one pipe per panel) which provide
one 1/16-in. dia. hole per valley. The pump runs whenever the collector
temp. exceeds the temp. of water at bottom of the storage tank. Water
flowing from the valleys is collected by a gutter (separate gutter for each
panel) and is delivered to the top of the tank. Expected average temp. of
water flowing from collector at sunny noon is: Jan.: 70 to 100 °F;
Mar.: 75-115 F. Collector panel wgt.,incl. glass: 2 lb/ft2; cost: $3/ft2.
Storage system layout:

Storage system:

Heart of system is a horizontal, cylindrical, 1600-gal. steel tank containing water. Tank is 4 ft in dia., 17 ft long, and has a 24-in.-dia. manhole at top center. Tank is situated inside of, and near bottom of, an 8 ft x 7 ft x 20 ft bin situated in west end of basement. Bin has cinder-block walls and bottom, and rests on a 5-in. concrete slab which in turn rests on a 1-in. layer of Styrofoam. Tank is surrounded by fist-size stones 28 tons of them. Above tank is a crawl space, and above this there is an array of copper tubes (200 ft.; 3/4 in. dia.) that serves as a part of the auxiliary heating system discussed below. Tank water is rain water (see below) and contains no inhibitor or antifreeze. Water from collector enters tank near tank-top and flows back to collector from tank bottom. When rooms need heat, a t-HP blower beside the base of the

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bin drives room air downward to bin via a duct the cross section of which is
30 in. x 28 in. I.D. The air then passos upward through the mass of stones,
is warmed by them, and then circulates (throughout entire area of floor)
in the 2-in.-thick space between first-story floor and basement ceiling
(of aluminum-coated gypsum board). Often, the blower is not needed: gravity
convection alone suffices.

Percent solar heated: No figure yet available. System did not start
operating until Dec. 1974. Carrythrough: No figure yet available.
Domestic hot water: A 40-gal. preheater tank is used and is situated inside
main tank, near top thereof. Preheater tank is of steel and is not insulated.
Final heating is by 56,000 Btu h' oil-fired heater, with its own 40-gal.tank.
Auxiliary heat: There is no furnace. But heat can be supplied to the bin of
stones by the oil-fired heater via the above-mentioned set of copper pipes
whenever a certain solenoid-controlled valve is open. Also, in winter, heat
from flue-pipe of oil-fired heater is scavenged; heater has two alternative
flue-pipes for winter and summer -- and the winter flue-pipe passes
through the bin of stones at level of uppermost stones; this flue-pipe is
8 in. in dia, and is of heavy (16 gage) galvanized steel. Summer flue-pipe,
invoked by manually operated damper, is 6 in. in dia, and is wholly outside
bin.

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Cooling in summer: In summer, a standard, 20,000 Btu, $400 air conditioner
is operated throughout coolest hours of the night (e.g., 10:00 p.m. until
4:00 a.m. -- off-peak hours) to dry and cool the air that is circulated
through the bin of stones. During hot part of day, air is circulated from
rooms to the bin of stones and back to the rooms, to cool and dehumidify them.
Humidification in winter: Humidification provided. Details not available.
Collection of rain-water: At present, rain-water can be collected from
sundecks, south portion of main roof, and half of north portion of main roof.
Later, collection will be from entire roof. Gutters for collecting rain-
water are separate from gutter system serving collector. Rain-water is used
to fill main storage tank. If, in summer, water from storage tank is used
to water lawns, the tank may be refilled next time there is a heavy rain,
Status: Bldg, ready for occupancy in Dec. 1974.

Total cost: Total cost, including bldg. and its solar heating system, but
not the land, is roughly $65,000. Incremental cost of equipment for solar-
heating the bldg. and solar-preheating the domestic hot water, and air-
conditioning (relative to cost of corresponding conventional equipment):
$1500 to $2000, per designer's estimate.

Sources of information: Wash. Star-News 10/4/74; P-900; US Patents
3,145,707, 3,215,134, 3,236,294, 3,254,643, 3,254,701, 3,254,702,
3,254,703, 3,270,739, 3,812,903.

67

WAS 1/17/75

West Virginia

Shanghai

(60 mi. NW of

Wash., D.C.)

Architects: Burt, Hill, & Assoc.; esp. P. R. Rittelmann.
Owner: A. N. Wilson.

Bldg.: 2-story, 2-bedroom, modern-type house with 1400 ft2 of
living area plus adjacent greenhouse and garage.

Collector: 600 ft2, flat-plate, water-type, on 45° roof.
Individual collector-panel is 8 ft x 2 ft and is of 0.040-in.
blackened aluminum with 2-in.-dia. aluminum tubes 6-in. apart
on centers. Panel cover: two layers of mylar beneath one layer
of glass.

Storage system: 2400 gal. (~10 ton) main tank and 400 gal.
(1 ton) supplementary tank. Same water-plus-ethylene-glycol
sol'n. used in collector and tanks. Main tank is of concrete
(partly integral with house basement), with liner and with
polyurethane-board insulation. Fan-coil system sends heat to rooms.
Percent solar heated: 80 (est.) Carrythrough: 2 days (est.)
Auxiliary heat: oil heater.

Cooling in summer: Air conditioner will be used, and the smaller
tank will store "coolness". (R-100, U-456m, U-456e, S.E.D. Oct. 173,
P-900). Status: Not started; funding problems.

collector

(10 panels)

-N

greenhouse and

passage to garage

68

VAS 1/17/75
Andorra

Padern

Padern College Solar Cabin 421° N.
1500 m altitude. 1975.
Architects: I. Hogan assisted by A. Gerrand and B. Ford. Advice (re
CNRS-type solar wall) from J. F. Robert.
Bldg.: Is first of five very-low-cost cabins, on S slope of a mountain
in the Pyrenees. Two stories. 19 m x 8 m, with long axis E-W. Roof
slope is 30° from horizontal, to conform to local building code. Bldg.
is well insulated; typical U-value is 0.4 W m−2 Oc-1. Many energy-
conserving features. Elec. supply from a 2-kW Electro-GmbH windmill
and 12-v batteries. Bldg. provides classroom, living room, 12 bedrooms,
utility room, etc., for 24 students. Low-cost, on-site materials used.
Construction mainly by students themselves.

Main collector: 80 m2, air-type, covering 90% of vertical S wall. Heart
of collector is a thick (35 cm) vertical, natural-dark-color, masonry
wall made with soot-blackened mortar. Single glazing is used and there
is a 20-cm air-space between glass and wall. (Other 10% of S wall
consists of 12 double-glazed windows. There is a 45-cm space between
glass layers, and such spaces are occupied by flower-filled boxes.)
Storage system: Masonry wall described above. Wall area: 19 m x 5 m;
thickness: 35 cm. Net volume:
26 m. Mass: 52,000 kg (115,000 lb).
Carrythrough: 3 days (predicted). During day, ducts carry hot air (by
gravity convection) from masonry wall to north rooms. At night, ducts
are closed to prevent reverse flow. Wall provides some radiant heating
also.
Auxiliary collector, for preheating domestic hot water: 30 m2 total,
25 net. Consists of 24 panels, each 21 m x 2m, on 30°-sloping roof.
Auxiliary heat; Catalan wood-burning stove for cooking. Organic
waste-disposal system provides some heat. No furnace or elec. heaters.
Percent solar heated: 80% (predicted).

Cooling in summer: Eaves shade upper portion of masonry wall near
midday in summer. Outermost layer of lower portion becomes hot and thus
encourages air in space between wall and glazing to flow up and out
through vents, by gravity convection; this in turn brings in cooler air
via slots and via ducts from N side of bldg. Inner face of wall remains
relatively cool because of the high thermal capacity and the low thermal
conductance. (P-900).

Canada

Surrey, B.C. (near Vancouver)

69

WAS 1/17/75

Hoffmann House 49° N.

1971.

5511 128 St., Surrey, B.C.

Solar engineer and owner: Erich W. Hoffmann.
Bldg.: One story (1400 ft2) plus basement (1300 ft2, partially
heated). House built in 1968, solar heating system in 1971.
Collector: 460 ft2 gross, 413 ft2 net. Flat-plate, water-type on
roof sloping 58° from horizontal. Radiation strikes 0.005-in. copper
sheet with non-selective black coating; -in. I.D. black copper tubes
are soldered to sheet. Double glazing: inner layer, 3/4 in. from
copper sheet, is of single-strength glass, pane size 3 ft x 3ft;
outer layer,3/4 in. from inner layer, is of double strength glass.
Water is circulated through
Collector backing: 6 in. fiberglass.
purp
collector by small centrifugal and is drained automatically at end
of day. Max. collection temp. (summer, no water in tubes): 270 °F.
Storage system: 800 US gal. in two vertical cylindrical uninsulated
tanks (300 gal, 500 gal) in insulated basement room. Max. temp.
achieved in tanks in summer: 170 °F. Carrythrough: one Jan. day.
Rooms are heated by air that has circulated (by gravity convection)
through tank room.

Percent solar heated: 40%.

Also, much heat is provided

for domestic hot water and

swimming pool.

Auxiliary heat; Electric

baseboard heaters. (P-900)

~ carport

France

Various Solar Houses Built in southern France, mainly in the last few
years, under the direction of F. Trombe, Director, Solar Energy Laboratory,
Centre National de la Recherche Scientifique. In a typical house, the
blackened face of a vertical south-facing concrete wall 35 to 40 cm. thick
serves as collector. Double glazing is used. There is a 10-cm. air-space
between glazing and concrete wall, and there are slots (10 to 20 cm. high,
Air
50 to 70 cm. wide) through the concrete wall at top and bottom.
circulates spontaneously upward between glass and concrete and downward
through rooms. In some houses a fan or blower is used. Typical volume of
Rule-of-thumb:
prototype house: 300 m3; typical area of collector: 48 m2.
collector area in m2 is one tenth the house volume in m3 (or one twentieth,
for houses on the French Mediterranean coast). The concrete wall itself
serves as energy store. Typically, the solar heating system provides 2/3
of winter's heat-need. Rooms are too cold on some midwinter mornings
(unless auxiliary electric heat is used) and are too warm on some sunny
afternoons (unless certain simple ventillation schemes are used), but are
entirely comfortable throughout most of the year.

(T-402, W-100, P-900)

concrete

N