"On a cold day there is nothing better
than a seat against a warm stove."
Select from the links below (or scroll down
page) to read quotes:
On Radiant Heat
from The Book of Masonry
Pattern Number 230 - Radiant
'Some National Stupidities'
by Mark Twain
|Sitting around a fire together for hundreds
of thousands of years is a big part of what makes us human.
(text provided by Tulikivi)
For 1.5 million years, we enjoyed the radiant
heat of the ancient wood fire. We used rocks to secure the fire
and as kitchen utilities. The cave people found heat from their
fires stored in and slowly radiating from the cave walls. As our
building knowledge grew, man figured out how to tame the fire and
how to store its heat more and more effectively.
We abandoned caves in favor of houses with stone
fireplaces. As winters set in, the fireplace became the center of
every home, where we could eat and sleep after a hard day of hunting
and gathering. Even today we crave the safety of hearth and home.
About 50 years ago, we started to heat our homes
and businesses more and more with forced hot air, the kind used
with radiators and central air. Fireplaces were phased out, especially
in the cities. Radiant heat became a cozy memory.
Forced-air heating uses the same principles used
in a hot air balloon. We heat metal plates with hot water or electricity.
These plates heat the air around them and this heated air is forced
through the room so that air is heated and rising all the time.
While this hot air might manage to keep us warm, it does little
To understand the implications of the transition
from radiant heat to forced-air heat, we have to understand the
effects of various kinds of heat on our bodies.
Man has dwelt in rather hot areas for most of
our evolution. So our inner thermostat is focused on cooling down
in order to keep our body temperature stable at around 96 degrees
When we digest the food we eat, we produce heat.
so our body has to assure that this heat can be expelled. Most of
this heat transfer happens through the skin, which has an average
temperature of 86 degrees. If youre too hot, the body pumps
more warm blood to your skin, which turns red.
When this happens you actually radiate about
the same amount of heat as a 100 Watt light bulb. The body also
uses the cooler surrounding air, evaporation and breathing as other
ways of cooling down. When traveling into colder areas, man found
that there was little his body could do to help him keep warm. Cold
causes blood to move away from hands and feet in order to reduce
heat losses, which is why cold turns you blue. If the body remains
cold it begins shivering, and teeth begin chattering. These muscle
movements create heat. Thats why prehistoric man developed
warm clothing and warmer shelter, and used fire to keep warm.
Basking in the sun and sitting by your Tulikivi
fireplace both help to keep your body warm in the same way. Scientists
call it radiant heat. its a kind of light that you cant
see. It has nothing to do with radioactivity! Cats see it quite
clearly and use it to catch mice in the dark.
Heat rays are also called infrared light, because
their wavelength is somewhat longer than red light. Infrared light
will heat up every object it falls upon. Heat rays from very hot
objects can penetrate up to four centimeters deep into your body,
though around one millimeter is quite enough. This is where about
a quarter of your blood flows to distribute heat throughout your
entire body. As long as the temperature of the heat source is higher
than that of your skin, you experience a direct heat transfer. thats
why sitting near a Tulikivi feels so great when you are coming in
from the cold.
With radiant heat, room air can be relatively
cold (64- 68 degrees) because the deep-heating rays compensate.
But the average heated room air doesnt heat up your body in
the same way. Your skin loses heat to warm air, albeit less than
with cold air. Forced-air heating only helps create an environment,
which is warm enough to keep your body warm through your own inner
fire. If room air gets too warm, it may cause you to breath more
quickly to remove heat, which may result in a restless, constricted
Conversely, cold radiation is rather unpleasant.
Cold stored in walls and floors can keep you feeling colder. This
syndrome is typical with forced-air heating systems, which heat
up room walls only marginally. Even if the room air is rather warm,
the cold radiation will cause the blood to withdraw from the skin.
The soapstone heat from our fireplaces vibrates
at precisely the same wavelength of your body radiation, at 8-9
µm. Scientists say this explains a lot about the general appreciation
for the quality of our heat, which we have recorded over the years.
The wavelength of hot metal surfaces is much shorter. It feels aggressively
hot when close by, but does not reach far.
Forced-air heating produces a vertical temperature
difference of up to 50 degrees, producing a warm head and cold feet.
Your body cant adjust to that. The thermostat in an air heating
system controls the air temperature at the level of the thermostat,
while creating the illusion that a desired "room temperature"
has been achieved. But to be really comfortable, the room would
need to have height differences, as in a sauna.
With radiant heat, the heat difference is horizontal.
So, by moving closer to or further from the heat source, both older
people sensitive to cold and younger people can find an area in
the same room where they feel comfortable.
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By David Lyle
Published by Chelseagreen Publishing
Some years ago, as I looked into the various
traditional methods of wood burning around the world, the depth
of feeling among masonry stove partisans began to come home to me.
They did not simply feel that masonry stoves were better; they felt
that, given an opportunity for choice, no
other choice could be made! At this point, rather like the
mule struck by the baseball bat to get his attention, I began to
feel that there might be a message here for North America. The farther
I looked, the more relevant the message seemed. Masonry stoves were
superior in a number of ways...
We are accustomed to iron stoves. That is our
tradition. Elsewhere in the world, many prefer masonry. So let me
begin by listing some of the virtues that well-designed masonry
stoves and fireplace-stoves may have:
||They are substantially more
efficient than the typical iron stoves on the market today.
||They are safer to live with
than iron stoves.
||They can sharply reduce air
Pollution from smoke.
||They fit in well with solar
||Masonry Stoves require fuel
only once or twice a day.
||They do not parch the room
air and so are more comfortable to live with than iron models.
||They offer design flexibility
impossible with iron; the masonry stove can be designed to
fit the house.
"As to the present value of old technology
in stoves, look for a moment at Finland. Finland is an advanced
country, known for fine workmanship and good design. The Finns are
international traders. Their products have to be good, especially
in regard to heating because their climate is like that of Alaska.
Today (1984) Finlands government actively encourages the construction
of masonry stoves through tax policy. About two-thirds of Finlands
new houses have built-in masonry stoves. Most of the rest have wood-fired
masonry baking ovens which can also be used for space heating. This
government policy says a good deal about Finlands confidence
in an old technology, even in the space age. It says something as
well about the countrys assessment of the energy situation.
Masonry stoves can sharply reduce wood-burning
safety problems. The iron stove is frequently so hot that it will
burn anyone who touches it. The masonry stove is commonly designed
in Europe with benches attached, so that you can sit and lean against
the stove. There is a world of difference in safety between a stove
you can lean on and one that burns at the touch.
Reprinted from The Book of Masonry Stoves
Rediscovering an Old Way of Warming
By David Lyle
Initially Published by Brick House Publishing
Now published by Chelsea
Green Press White River Jct., Vermont
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This pattern is a biologically precise formulation
of the intuition that sunlight and a hot blazing fire are the best
kinds of heat.
Heat can be transmitted by radiation (heat waves
across empty space), convection (flow in air or liquids by mixing
of molecules and hot air rising), and conduction ( flow through
In most places, we get heat in all three ways
from our environment: conducted heat from the solids we touch, convected
heat in the air around us, and radiated heat from those sources
of radiation in our line of sight.
Of the three, conducted heat is trivial, since
any surface hot enough to conduct heat to us directly is too hot
for comfort. As far as the other two are concerned - convected heat
and radiant heat - we may ask whether there is any biological difference
in their effects on human beings. In fact there is.
It turns out that people are most comfortable
when they receive radiant heat at a slightly higher temperature
than the air around them. The two most primitive examples of this
situation are: (1) Outdoors, on a spring day when the air is not
too hot but the sun is shining. (2) Around an open fire, on a cool
Most people will recognize intuitively that
these are two unusually comfortable situations. And in view of the
fact that we evolved as organisms in the open air, with plenty of
sun, it is not surprising that this condition happens to be so comfortable
for us. It is built into our systems, biologically.
Unfortunately, it happens that many of
the most widely used heating systems ignore this basic fact.
Hot air systems, and buried pipes, and
the so-called hot water "radiators" do transmit some of their heat
to us by means of radiation, but most of the heat we get from them
comes from convection. The air gets heated and warms us as it swirls
around us. But, as it does so it creates that very uncomfortable
stuffy, over-heated, dry sensation. When convection heaters are
warm enough to heat us we feel stifled. If we turn the heat down,
it gets too cold.
The conditions in which people feel most confortable
require a sublte balance of convected heat and radiant heat. Experiments
have established that the most comfortable balance between the two,
occurs when the average radiant temperature is about two degrees
higher than the ambient temperature. To get the average radiant
temperature in a room , we measure the temperature of all the visible
surfaces in a room, multiply the area of each surface by its temperature,
add these up, and divide by the total area. For comfort, this average
radiant temperature needs to be about two degrees higher than the
Since some of the surfaces in a room (windows
and outside walls), will usually be cooler that the indoor air temperature,
this means that at least some surfaces must be considerably warmer
to get the average up.
An open fire, which has a small area of very
high temperature, creates this condition in a cool room. The beautiful
Austrian and Swedish tiled stoves also do it very well. These are
massive stoves, made of clay bricks or tiles, with a tiny furnace
in the middle. A handful of twigs in the furnace give all their
heat to the clay of the stove itself and this clay, like the earth,
keeps this heat and radiates is slowly over a period of many hours.
Choose a way of heating your space - especially
those rooms where people are going to gather when it is cold - that
is essentially a radiative process, where the heat comes more from
radiation than convection. ...
...it is also very wonderful to make at least
some part of the radiant surfaces low enough so that seats can be
built round them and against them; on a cold day there is nothing
better than a seat against a warm stove.
From A Pattern Language by Christopher
Alexander, Sara Ishikawa, Murray Silverstein
Published by Oxford University Press - 1977
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"The slowness of one section of the world
about adopting the valuable ideas of another section of it is a
curious thing and unaccountable. This form of stupidity is confined
to no community, to no nation; it is universal. The fact is the
human race is not only slow about borrowing valuable ideas
it sometimes persists in not borrowing them at all.
Take the German stove, for instance to
the uninstructed stranger it promises nothing; but he will soon
find that it is a masterly performer. The process of firing is quick
and simple. At half past seven on a cold morning one brings a small
basketful of slender pine sticks and puts half of these in, lights
them with a match, and closes the door. They burn out in ten or
twelve minutes. He then puts in the rest and locks the door, and
carries off the key. The work is done. He will not come again until
next morning. All day long and until past midnight all parts of
the room will be delightfully warm and comfortable.
Americans could adopt this stove; but no, we
stick placidly to our own fearful and wonderful inventions of which
there is not a rational one in the lot. The American wood stove,
of whatsoever breed, is a terror.
There can be no tranquility of mind where it
is. It requires more attention than a baby. It has to be fed every
little while, it has to be watched all the time; and for all reward
you are roasted half your time and frozen the other half. It warms
no part of the room but its own part; it breeds headaches and suffocation,
and makes ones skin feel dry and feverish; and when your wood
bill comes in you think you have been supporting a volcano.
Consider these aspects of the Masonry stove.
One firing is enough for the day; the cost is next to nothing; the
heat produced is the same all day, instead of too hot and too cold
by turns; one may absorb himself in his business in peace. Its surface
is not hot; you can put your hand on it anywhere and not get burnt,
yet one is as comfortable in one part of the room as another"
From "Some National Stupidities"
written in 1891
We agree. Residential Masonry Heating is as
valid today as it was during Mark Twains time. Built to last,
Masonry stoves manage to combine beauty with proven energy efficiency.
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