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Super-Solar Houses
_Super-Solar Houses--Saunders's Low-Cost, 100% Solar Designs_
By William A. Shurcliff (with extensive help from Norman B. Saunders)
Copyright 1983 by William A. Shurcliff
Brick House Publishing Company, Andover MA
Table of Contents
1. Introduction 1
2. Preview of the Three Houses 7
3. General Strategies 15
I. Shrewsbury House
4. Shrewsbury House: Specific Strategies 23
5. Attic Solar Window 38
6. Upper Thermal-Storage System 46
7. Lower Thermal-Storage System 49
8. Greenhouse 53
9. Air-Drive System 57
10. South Window System 61
11. Non-South Windows 65
12. Other Components 67
13. Operation in Summer 72
14. Performance 76
15. Cost 84
16. Discussion 85
II. Cliff House
17. Cliff House: A General Overview 91
18. Sunspace 99
19. Thermal-Storage Systems 105
20. Main Airflow System 108
21. Other Components 113
22. Wintertime Performance 115
23. Keeping Cool in Summer 117
III. All-Solar-Too House
24. All-Solar-Too House: Main Goals
and Strategies 121
IV. Comparison
25. Comparison of the Three Houses 131
Patents and Trademarks 137
Bibliography 138
Index 140
Introduction
------------
This book is about three remarkable houses. One, called Shrewsbury House,
was essentially completed and occupied late in 1981; through two winters
and one summer it has performed with full success. Another, called Cliff
House, is nearly complete as of this writing (May 1983.) The third, called
All-Solar-Too House, is a design prepared for the 1982 Gardenway Passive
Solar Design Competition; as yet no construction is scheduled.
Main Performance Features
All three houses, employing unique solar heating systems invented and
engineered by Norman B. Saunders of Weston, Massachusetts, are 100%
solar heated. More exactly, they are kept warm by intrinsic heat sources
(human bodies, electric lights, cooking stove, etc.) and by solar energy.
None has a furnace or wood stove. Also, all stay cool in summer.
The "100% solar heated" claim [now much stronger, in 1995, after 12 years
of electronic data logging of house temperatures, etc.--Nick] needs some
slight qualification. Although the houses will remain comfortable throughout
the winter without auxilliary heat, the occupants may, on certain occasions,
make use of a small electric heater to make one room extra warm, if someone
in the house is ill, or to accelerate the drying of fresh paint. And they may
do so when, for experimental purposes, various changes are made in system
components or in control procedures. One house, Cliff House, has a fireplace
that was included for reasons of esthetics.
All three houses have many attractive features other than heating
self-sufficiency. Operation is automatic, or hearly so. The houses
remain fairly warm in winter even if left unoccupied for a week or more.
Each has an integral south greenhouse or sunspace. Each has ample window
areas, not only on the south, but also on the east, west and north.
In each of these houses, the space heating system employs no conventional
collector panels, no pumps, no valves, no drains, no moving liquid, no pipes.
There are no Trombe walls. In none of the living-area rooms is there any
bulky equipment used solely for space heating. Thus there is great freedom
of choice in room layout, furniture placement, etc.
All three houses have automatic passive solar preheating of the domestic
hot water supply.
Low Cost
For each house, construction cost is low--about the same as for a conventional
house of comparable size and comfort. More interestingly, the construction
cost is comparable to, or slightly lower than, that of a typical 40-80%
passively solar-heated house, and it is much lower than that of a typical
_actively_ solar-heated house.
How can the cost be so low? Because:
o Most of the components consist of low-cost materials--air, water,
stones, glass, plastic, fiberglass, etc.
o Most of the components can be assembled on-site by carpenters and
others of typical competence.
o There is no furnace, no oil tank, no furnace room, no furnace
chimney, no radiators, no air conditioner.
Operating cost is low--$50 to $100 per year for electric power to run the
one or two small fans that are the heart of the temperature control system.
Comparison with Other Leading Designs
How do these three houses compare with other outstandingly successful,
energy-conserving passive solar houses in the United States and Canada?
It is premature to make judgements with respect to Cliff House and
All-Solar-Too House. But Shrewsbury House has been in use throughout two
winters and one summer, and the record is clear: its performance has been
superb. I make the guess that its performance equals or surpasses that of all
other houses--in the USA or Canada--of comparable size, comfort, etc.
Many hundred superinsulated houses have been built and operated for
one or more years and have performed excellently. They keep warm in
winter and cool in summer. But nearly all of them require an auxiliary
heating system. Most have no greenhouse. Many require operating thermal
shades in the evening and in the morning. Many have smaller-than-normal
areas of windows on the east, west, and north sides of the house.
Scores of double-envelope houses have been built and operated for two
or more years. They have performed well, and annual fuel bills have
been of the order of $200 or less. But auxiliary heating systems are
needed and some rooms are sometimes on the chilly side. Many double-envelope
houses entailed considerable extra construction cost, of the order of
$5,000 to $15,000. (Some early builders of double-envelope houses have
recently lost some of their enthusiasm for the double envelope itself
and are attaching greater significance to earth-coupling and solar energy
storage--a shift toward some of the features that, in Saunders-designed
houses, play major roles.)
About 100,000 passive solar houses that have large areas of south-facing
windows and much added thermal mass have been built and have been in use
for two or more years. Nearly all of these require auxiliary heating systems;
many require large areas of thermal mass that preempt space in the most
important part of the house--the south part; many employ large thermal
shutters or shades that must be operated twice a day; many suffer from
excessive glare on sunny days; many tend to overheat, especially on very
hot days late in the summer when the solar energy input via the south
windows is especially large.
Clearly it is a noteworthy advance when a solar engineer develops designs
that, besides requiring no auxiliary heating system, provide an integral
greenhouse, have ample window areas on all sides of the house, operate
automatically (no thermal shutters or shades to operate), reduce glare,
keep cool in the summer, and solar-preheat the domestic hot water supply.
To do all this at a cost that is no greater than that of a conventional
house is a landmark achievement.
The performance of the Shrewsbury House is now well proven, and I am
confident that Cliff House and All-Solar-Too House have the capability
of approximating its superb performance.
Crumbling the Classic Rule, "Do not try to achieve 100% solar heating."
Ten years ago, most solar architects and engineers were convinced that,
in designing houses for cold climates (such as New England), it was foolish
to try to achieve 100% solar heating. Prestigious experts made detailed
calculations that showed conclusively (they said) that, in New England
for example, it was unwise to try to achieve more than about 50-70%
solar heating. They warned that the cost of achieving a higher percentage,
such as 80% or 90%, would be enormous and would far outweigh the benefits.
Even if the designer were to double the size of the collector and double
the size of the storage system, he would get only about 90% solar heating.
To achieve 100% might require tripling the sizes, and much of the added
capacity would be useful only on five or ten days a year.
Especially clear warnings against attempting to achieve 100% solar
heating in cold climates are contained in articles by G. O. G. Lof and
R. A. Tybout. See, for example, their article in Natural Resource Journal,
Vol. 10(2), p. 268, 1970, or their article in Solar Energy, Vol. 14, p. 253,
1973. Tybout was an economist and Lof was one of the world's foremost solar
heating experts...
Faith in the experts' negative pronouncements began to weaken a few years ago,
with the advent of superinsulated houses. By 1981 there were hundreds of such
houses, and by the spring of 1983 one or two thousand had been completed or
were under construction in the USA or Canada. Most of these houses require
only $50 to $150 worth of fuel per winter, and a few come close to being
100% heated by the combination of intrinsic heat and direct-gain solar energy.
Many such houses have no furnace, but do have a wood stove or a small electric
heater.
The final crumbling of the experts' gloomy view occurred in January and
February of 1982. In these midwinter months, Robert Bushey, owner and
occupant of Shrewsbury House, found that his house held at about 70 F--
day and night, in clear weather adn overcast weather, with no backup heat
at all. The goal was reached: 100% solar heating in a cold climate! It was
reached at no extra cost. For good measure, the goal was achieved without
turning the thermostat that controls the fan below 70 degrees F, without
reducing the areas of east, west, and north windows, without needing to
close thermal shutters each night and open them each morning, and without
curtailing fresh air input.
Why a full-length book?
To devote an entire book to three solar-heated houses may seem absurd.
A typical solar house can be described in a few pages.
But Saunders's three low-cost, 100% solar houses are different--very
different. They embody several radically new approaches to solar heating.
The design goals and also the general strategies used are new and strange, and
some of the key components are puzzling even to experienced solar designers.
A galaxy of new concepts is involved.
To clearly convey what the designs are all about, and what exactly the
heating and cooling systems consist of, requires a book.
Norman Saunders: Inventor and Doer
Norman B. Saunders, a professional engineer residing at 15 Ellis Road,
Weston, MA 02193, is a thoughtful, quiet, deliberate inventor: an inventor
of the lone-wolf type and one of New Englands's best known solar consultants.
His passion is devices that are simple, homely and durable. He avoids
like the plague any device that is merely brilliant, flashy, impressive, or
striking. From forty years' experience in physics, mechanical engineering,
electrical engineering, and electronics engineering, he has developed the
greatest distrust of "brilliant" devices which, so often, turn out to cost
three times as much as anyone had predicted and to break down much too
promptly.
He turns his back instantly, with no apology, on most types of conventional
solar heating equipment.
Ignoring popular trends in solar design, he goes his own way, trying
to formulate the heating and cooling requirements in the simplest and
most basic way possible.
One of his main approaches is to use a multipronged attack: use a lot
of "little" pieces of equipment that will work together well. Each,
although simple and unimpressive, contributes significantly. Together
they provide a full but low-cost solution.
Accordingly, his inventions cover a broad range, from special glazing
materials and special window structures to special south roof louver
systems, special heat-storage assemblies, and special airflow controls; also,
various special systems for use in commercial buildings, eg high-temperature
(steam-producing) systems. (The appendix lists many of his patents.)
But he does a lot more than think and patent: he tries out his inventions
prompltly. He puts them to work, either in his own house or in houses of
friends or clients. Often he continues to improve a given invention,
year after year.
Some of the solar houses that he has designed--and that have worked well--
are described in my earlier books... His first solar house is described in
his book Solar Heating Basics [a new edition may be coming... :-)] and in
a very recent report. See also the book by Carriere and Day.
I have found his patents hard to read, hard to understand. My impression is
that very few people have given the patents the attention that they deserve.
He has written a number of reports on his inventions, but they are heavy
reading.
For all these reasons, his major contributions to the art of solar heating
have been, until now, little known outside of New England. This is true even
though he has been generous with his time in presenting papers on his
developments at various meetings of solar energy societies and in giving
monthly talks and seminars to local groups on the theory and practice of
solar heating.
...
Some patents (copies of which are available for $3 each from The Commissioner
of Patents and Trademarks/Washington, DC 20231)
3,952,947 4/27/76 Solar heating system employing controlled
introduction of outdoor air via a special window.
4,078,603 3/14/78 Skylight-type collector with storage and
distribution systems.
4,123,002 10/31/78 System for controlling air temperature, humidity
and ventilation with use of ground coupling.
4,157,639 6/12/79 Seals for vertical and sloping windows or glazing.
4,201,189 5/6/80 South window solar-radiation absorbing element (as
in Shrewsbury House and All-Solar-Too House.)
4,296,733 10/27/81 Transparent roof employing reflective louvers that
admit much solar radiation in winter and admit little
solar radiation in summer.
Note: US patents are normally valid for 17 years from date of issue.
Nick