THE "SOLAR SPIRAL"

HOW TO REDUCE THE NATURAL ENERGY CONSUMPION OF BUILDINGS THAT 'LOOK INWARDS' TO A LARGE INTERIOR SPACE THAT WE CALL "THE REPUBLIC OF THE VALLEY".

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A NUCLEAR FURNACE The fact that the sun is a nuclear furnace is one of the best kept secrets of contemporary British Architecture. One reason for this must be that for the greater part of the day its power is hidden behind a welcome blanket of cloud. These vapours sprinkle our little island with gentle rain and makes it rather easy to grow tender plants. Hence the illusion that 'the Island Albion' is not burnt as white as a desert, as the meaning might indicate (alba being Latin for white) but is as green as a garden. I say 'illusion' because this 'green' is only a veneer. Pull to one side any part of the luxuriant foliage and one finds everywhere secreted, like the silent natives that accompany the Explorer, their shadows flitting amongst the branches, a 'rusticated' population of many millions and a thriving 'disurbane' commercial life. A DIMINISHING RESOURCE One must not be surprised if, congruent with this dissimulated 'urbanity' (or simulated disurbanity, for, whichever way one turns it, the British lifespace, like Alice in Wonderland, is never what it seems), one finds a powerful, well-supported cult of the 'invisible building'. The Architecture for this type was canonised 150 years ago, in the aptly-named Crystal Palace. Since then the intellectual and literary culture of British Architecture has been slowly and steadily draining away, like pages bleached blank by too much light. Architecture as a means to the Public manifestation of Ideas, made patent by various subtle means so as to become 'embodied' in 'natural' space, has slowly lost all of its underpinning culture until, today, like the Cheshire Cat, it remains the mere memory of a vacant smile. THE CULT OF NEGATION A whole building can not be made invisible, that is constructed of glass. This must seem obvious, for such a recourse can not be entirely practical. Yet a lack of utility is no longer considered a defect - rather the reverse in fact, - 'contrafunctionality' being all the rage today. Even so at least it may seem as possible as it is reasonable that the roof over a central courtyard, or 'Atrium' could be glazed. EVEN THE SUN DISAPPEARS! Yet this brings us to some more of the well-kept secrets amongst British Architects. There is, for example, the fact that the sun sets in the evening and rises in the morning - which is to say that, over Britain at least, the sun does not shine at night. Perhaps again there is a reason for this Native confusion. For, within living memory, Britain was the possessor of a mighty empire, the greatest that there has ever been, "on which the sun never set". Do British Architects carry on a folk-memory of these eternally brazen skies. It was well known, in 19C Britain that even if God was not an Englishman (which many agreed, at that time, was more than likely the case) then at least to be born an Englishman was to be born into a celestial condition. One proof of this, as sung by the great Noel Coward, was that Englishmen could "go out into the mid-day sun", when it was at its zenith, pouring photons into the earth like a Death Star, while all others, ancient Natives of those torrid Imperial skies, remained timidly in the shadows. For it seems never to concern these brave Architects that the ceiling of their glass-roofed rooms will go black at night, and remain so for many, many, hours, especially through our long, cold winters. One looks in vain for the 'black-painted' period in Native British ceiling decoration. So why does it so attract the 'Architects of the Invisible' that they roof the main, focal, social space of all buildings with black glass just at the time when everyone needs to be cheered-up - at night. Is it to encourage the common British response to all despairs - a recourse to the Alehouse, or today, amongst the young, to a draught of something stronger? LIGHT WITHOUT HEAT: THE IMPERIAL ELIXIR Then again, when the nuclear furnace we call the sun does heave up above the earth's rim, why do the Architect's of today remain studiously careless of the fact that, at mid-day, the sun is pouring so much energy through a glass roof that any room underneath it will overheat and need refrigerating so as to keep its temperature down even to that of the air outside the building. What this means is that during any warm weather, even in Britain, a glass-roofed 'Atrium' will get too hot to use unless it is bathed in refrigerated air. There is, as one might expect, a simple solution these peculiar native myopias. I will here describe the part of it that is easy to understand, and even easy for the contemporary practitioner to accept. I call it the 'Solar Spiral'. SOME FACTS The sun, in the Northern hemisphere, rises in the East. As it does so, its elevation above the horizon is low. It will penetrate any East-facing window and reach to the back of the room. At first it throws little energy through the thick atmosphere of the Earth. However, as it rises, it has to cut through less and less of our protective veil until, only two to three hours after rising, it begins, during the six summer months, to overheat an East-facing room. It is soon after this that the populations of most workplaces begin to arrive. If the workplace has the big 'picture-window' typical of the late 20C building, they can find an office, even in Britain, that is already too warm. As the sun rises up to mid-day it gets hotter and hotter but it reaches less and less far into the room. During these hours the occupants are not only 'at home', and capable of operating blinds, but the sun, being higher, is easier to exclude from the room. However, if the room began by being too hot when the workforce arrived, and there is if no refrigeration fitted, then there is no easy way to cool surfaces that have been 'insolated' or warmed in their material bodies by the incidence of the early morning sun. After lunch things, even in Britain, can get even less comfortable. The body heat of the occupants, and their electronic machines, and their task-lighting, is being absorbed by the air in the workroom. The fabric of the building also is now heating up after several hours of insolation. If the after-noon sun, as it descends, should now strike deep into unscreened rooms, the temperature will easily exceed that of the 'comfort zone'. The 'Solar Spiral' recognises the 'natural history' outlined above. SWANLEY: A FIRST COURSE OF TREATMENT We can break its 'medicine' into two courses of Architectural Treatment. The first was tried and proven in 1983-5, in our Harp Heating headquarters in Swanley, Kent on the Southern extremity of the built-up area of London. All rooms that did not face North were fitted with fabric 'butcher' blinds. These were released by an electric motor and fell out, under their own weight, away from the window. The blinds were actuated by a pair of photoelectric cells that measured the inclination of the sun and whether it was behind cloud. This was the first time such a system had been used in the UK. Its advantage was that the blinds only extended far enough to shadow the interor of the room. This meant that during the warmest months of the year, when the sun is at its highest, the blinds never came down far enough to obscure the view out of the window. Prior to our project, blinds had always come either fully down or retracted fully up. The former meant one could not see out, the latter shaded nothing. Needless to say, the achievement of a coherent electronic logic circuit, for our turbulent and cloudy skies, proved beyond the intellectual capabilities of the blind manufacturer, the largest in Britain, and was solved by a friend of the building owner, himself a History graduate from Cambridge. The effects of the blinds, when combined with the timed extinction of the task lights, and their afternoon relighting by personal action only, together with a localised, computer-optimised, heating system run off the wall hung boilers sold by the Owner, trickle ventilation, a double-skinned roof vented by solar-actuated fans and 'Working Order' vertical brise-soleil columns shutting out lateral sun, created one of the earliest low-energy 'green' projects in Britain. These recipes cover the smaller workrooms. In time JOA developed further 'treatments' mainly involving uncovering the concrete ceiling of workrooms so as to use it to absorb the heat that builds up every day. This heavy, cool, ceiling needs to be cooled overnight - essentially by losing this heat, by various means, to the night air. CAMBRIDGE: THE SECOND COURSE. We can now leave the 'first course of treatment' - for the smaller workrooms, and come to the 'second course of treatment' at the place where the 'Solar Spiral' came into being as an idea:- the Judge Institute Business Studies, for Cambridge University, England. We had, even back in 1990, an injunction not to use 'air-conditioning'. Consequently we designed this £M11.5 project with forced ventilation, certainly, but no refrigeration except in the single chamber of the Computer Classroom. This would not have proved possible if JOA had roofed the Atrium, or Gallery, as we prefer to call it, in glass. As it is this 80'0"-high (26M) space is always cool in summer and warm in winter, even in the most extreme conditions. One can 'sit-out' in any one of its many 'seminar-balconies' and be comfortable while those outside are either sweating or freezing - and one can do both, even in mild, cloudy, little, Cambridge. Needless to say that the Gallery has a solid roof. This means that it never overheats, even in a summer heatwave. It is however well-lit, having a four-storey glass wall to its East and an eight-story wall to its South. GRADING, NOT JUST SHADING These walls, as one must expect from our Architecture, are not mere slabs of glass. JOA do not subscribe to the prevailing iconic paranoia that grips, especially, the cultured classes in Britain! The large, rounded, bulk of the 5'0" (1.5M) diameter 'Working Columns' act not only to merely shade some of the direct sunlight, but to reflect it. Their rounded flanks grade the violence of 'natural' illumination, passing it through a range of graded grays, from light to shadow. This rounding softness is also applied to the glass wall transomes, in brake-pressed metal, all the way up the full 80'0" height of glass walls. The object of this is to abolish one of the many inadequacies of all 20C 'Picture Window Architectures' - the temporary blindness that accompanies the traverse of the labouring iris of the eye as moves from window to wall and vice versa. One goes temporarily blind as one looks from the view to the interior, and vice versa. This does not happen in old buildings whose window embrasures, set in thick walls, are painted with pale colours to perform this mediation between the sun's power and the interior. But who is taught the environmental commonplaces of our forefathers in the Architectural Academy of today? THE 'REPUBLIC OF THE VALLEY' AS A 'THERMAL SINK' The early morning sun enters the Gallery, bouncing off this rounded framework as well as off the 'light shelves' - to which we will shortly turn in more detail. The gallery is vast. Its surfaces are complex and many-facetted. Its volume of enclosed air is huge. The early morning sun falls into it, even on the hottest of summer days, without noticeable effect. By ten o'clock, when the sun's energy could be becoming oppressive, it is beginning to be shaded by the horizontal light shelves. These out-jutting fins of white coated aluminium are fitted to all of the windows of the Judge, even the ones to the smaller workrooms. Their effect is both to shade the interior from direct sunlight, and to reflect a small fraction of this energy, that they otherwise block, inwards and upwards onto the ceiling - from which it falls back, into the room, as a gentle luminosity. A SIMPLE TOOL, THE 'LIGHT-SHELF'. When the sun is in its zenith the whole eight storeys of the South-facing glass wall is cast into shadow by the outjutting light shelves. Moreover, such is the nature of insolation, being unwelcome in Summer, yet welcome in Winter, that the shelves can be calculated to give a very fair performance without being moveable, and prone to mechanical problems, maintenance and so on - not to mention enormously less costly than the mechanised kind. The entry of the sun, except for sundry shafts of brilliant light that peep around the light shelves, as well as the vertical columns, which act as vertical 'brize soleils', is, by the mid-day hour, beginning to be blocked by the bulk of the buildings around the Gallery. HIGH-LEVEL VENTILATION AND TEMPERATURE GRADIENT. For as the sun passes noon it meets with a wall of masonry that extends up to just below the eaves of the Gallery roof. Here, just below the roof, on the Western side, is a row of half-round 'lunette' windows. These, like the full circular windows on the Eastern side are power-operated to allow cross-ventilation in case the internal air overheats, or if smoke is needed to be cleared by fire-fighters. They have never been used to keep the Gallery cool. It has proved unnecessary. The huge volume of air, and the high thermal mass of the Gallery, is sufficient to keep its temperature steady through any diurnal variation. All that the Gallery needs is for the air to be sucked off the top of the space and pumped down certain of the 'Service columns' to be blown out at the bottom. This has the effect of equalising the 'temperature gradient' in this high space and prevents one becoming too warm at its top or too cold at its bottom. WESTERN DEFENCES The 'Western Wall', of the Judge Institute accommodation, screens the Gallery, preventing heat build-up. Its rooms, in turn, are screened from the afternoon sun by window-blinds. However here again, as at mid-day, a few isolated, but brilliant, shafts penetrate through to the Gallery. This is especially so at both Ground and Second Floor levels where the Western rooms are social spaces abutting openly onto the Gallery. The light, falling onto the blond wood floor of the Common Room and the black and white Carrara marble floor of the Entrance Lobby, bounce an animated illumination, crossed by the moving shadows of the Users, upwards into the Gallery void. THE DEAD SUN OF DISSUMLATION The one orientation which is almost wholly disregarded by the 'Solar Spiral' is what is termed 'North Light. This dreary grey shade, flat and unrelieved by either brilliance or gloom, is, as one will no doubt have already sensed, favoured by the aniconic minimalists of the glass roof tendency. Being supported in their project of dissimulation by the so called 'Arts Establishment' - a tendency as afraid to manifest their collective 'high-culture' as they are ignorant of the Architectural techniques by which it can be done - and on the other hand being trapped by the tiresome antics of the sun, what can the Architects of the Invisible do but expose their aniconic interiors, veneered in the ultimate illiteracy of a 'natural' material, to the soporific greyness of 'North Light'. One longs for even a solitary shaft of direct sunlight, however narrow, to fall upon some bright, intelligible, cultured, literary sign of iconic intellgence, however it might be constituted in these in greyed-out glass tombs. But the Architects and the Environmental Engineers have proudly ensured, by costly devices and careful calculations, that such enlivening moments do not occur. Their Clients and Users, for their part, having prohibited the manifesttion of any such graphic and visual intelligences anyway, what would the sun's ray iluminate? One cannot spotlight the star of an empty stage which has no decor for a play that no-one has written. CARDINAL POINTS OF THE SOLAR SPIRAL These, then, are the evaluations given by the Solar Spiral to the cardinal points of the Sun's traverse. To the East a general welcome, at least into the major internal social space that we call, in our Architecture, a 'Republic of the Valley'. To the South, a denial by columnar vertical 'brise-soleils' and horizontal 'light shelves'. To the West a total exclusion, unless it be in the merest shafts and spots of light, preferably of 'bounced' light. Finally, from the North: no great interest for social spaces. The only use of North Light is to be a 'working' light from which all shafts of direct light, however exiguous, must be excluded for some reason more compelling than the mere iconic inadequacy of the lifespace-Inventors. The effect of this evaluation upon the form of buildings surrounding the gallery-spaces of the 'Republic of the Valley' can be seen in some appended sketches, and studied, in live action, at the Judge Institute, Cambridge University, England.         End of The "Solar Spiral", Return to "JOA Toolbox: The Solar Spiral". .           * JOA can be reached by E-Mail at anthony@johnoutram.com , by telephone on +44 (0)207 262 4862 or by fax on +44 (0)207 706 3804. We also have an ISDN number : +44 (0)207 262 6294.