Post 388 ⇒   by Gautam Shah 


Guardrails are, both, protective barriers and rails for guidance. These are placed against a drop in terrain (of more than 750mm), against the edges of exclusive passage, or rights of ways. Guardrails, mark a visually recognizable guide line. Such guide lines are recognizable in inclement weather (heavy rains, fog, smog and darkness). A guard rail often is designed to bear heavier impact of side thrusts in comparison to a hand rail. A hand rail, as per most of the building standards cannot have a gap larger than 100 mm, whereas for Guardrails can have a gap slightly smaller than the front wheel dia of the vehicles, or at least 220mm.


Interstate Highway through Colorado > Wikipedia image by Retaildesigner

 Guardrails are placed in buildings, terrains and roads. Many of the edge side structures such as, hand rails, parapets or fences can be called guard rails. Guardrails are both man-made structures or contoured natural features. Guardrails on any type of passage ways should be minimal. Modern roads are designed in a manner to eliminate the need for a guard rail. These means include provisions of apron spaces, contoured ends and landscaped features to indicate presence of zones of dangers. Road barricades work as guardrails. Many are installed as temporary (demountable) or permanent structures to prevent surprise or forced entry of terrorists or demonstrators.


Kaluga region Trassa Road side barricade > Wikipedia image by Denghu at English Wikipedia


Jeresy type barriers against car attacks in Israel  >Wikipedia image by Netanel h


Protective Road Guardrails or barricades -folding and lightweight by Police > Flickr image by Indi Samarajiva


Guardrails are essentially of two types: 1. Rigid ones bear an impact to an extent, but mainly help bounce back of the object in certain direction, and possibly retard the movement of the object; 2. Flexible ones bear the impact substantially within the body and yet redirect the object to a safer zone. In both the cases an objective is to keep the vehicle upright while being deflected along the guardrail.


Lantau Island Sunny Bay Road HK > Wikipedia image by Summa06

 Road guardrails are designed with the roads or installed as retrofit when certain sections show such a need. Former types of guardrails are fairly long whereas the later types are zone-specific and comparatively shorter. Specific types of guide rails are placed to prevent accidents due to the road elements or fixed objects. These elements include bridge supports, piers, road signages, culverts, trees, etc.


Live Guards forming a Rail for crowd control > Wikipedia image by Craig Martell

 Guardrails on roads and other sites have the inner edge (use or the movement side face) completely free of obstructions. The rails are so constructed that they form a continuous visual and functional surface. The joints formed with a backing element rather than by lapping. The colour and surface texture are consistent.


Crowd anti stampede Guards at Saltergate > Wikipedia image by Jaxban 

 Guardrails function as an integrated system where the guardrail, posts, post foundation structure and support braces, all share the impact load. In spite of a rigid design, guardrails do deflect. The amount of deflection depends on such factors as: straight or curved formation of the guardrail layout, height of the guardrail, shape or section of the rail, direction of the impact (parallel, head-on, angular), weight of impacting objects (mass-inertia), height of the impacting object, nature of support posts, and distance between the supports.


Guardrails for Niagara Falls > Wikipedia image by Wladyslaw

Road and other guard rails are universal structures, serving variety of vehicles (cars, trucks, motorcycles, cycles), people (adults, infirm, children, rowdy crowds), climatic conditions (rains, fog, smog, snow), and varying terrain conditions (floods, landslides, dumping, oil leaks). An optimum height for a car may not prevent a truck from toppling over the rail and a motorbike or human being sliding under it.


Barricade Bollards > Pixabay free images by serghei_topor Enter a caption



Post 387 – by Gautam Shah




Water wells are deep terrain entities. The wells are used to draw water or go down and reach the water for ritual procedures. To draw water one needs a rope and bucket, but wells have stepped access. The stepped access have taken many different architectural forms. One or multiple straight directional access systems have been used. Wells with spiral stairs have equally varied forms.

Central Murray Road footbridge Clockwise spiral stairs HongKong

Spiral stairs are of FOUR basic types: 1. Winding around a central supporting pole, 2. Winding as projection from surrounding square or circular peripheral structure, with or without a central open space, 3. Steps supported on both the edges within a double walled drum, and 4. A free spiral supported only at top and bottom ends.

Wells with spiral stairs are ancient structures, and fairly deep one, so the spiral stairs of type 4 (as above) are not found. Deep wells with several helical winds make the central support (as in item 1 above) very heavy, and its failure can collapse the stair structure entirely. Wells with spiral steps winding as projection from the surrounding square or circular peripheral structure are possible with steel or concrete constructions. But with stone as the material for constructing projected steps, chances shear failure are high. Spiral step-wells, as a result are structures where steps supported on both the edges within a double walled drum.

Sidi Bashir Mosque Ahmedabad India Minarets with spiral stair

Spiral stairs can be clock-wise and anticlockwise in terms of ascent (or descent). For ascent clockwise movement is favoured for two reasons. Ascent is more strenuous then descent, and clockwise movements are easier for right handed persons (larger populace who by nature or forced habit are right handed). Spiral stair steps are narrower on the inner end, and wider on the outer edge. This forces the user to select a position where the steps are of just right size (the tread width). This however, must be achieved by taking support of the outer wall (or its railing -if there is one). These two conditions make a spiral stair passage comparatively of narrow width. The narrow width makes the use of stair difficult for concurrent ascent and descent.

Double Helix Spiral stair with open core at Vatican Museum

Double Helix Spiral stair with open core at Vatican Museum

Circular stairs with large diameter and with open central core have the advantage of a more consistent tread width. Such stairs have sufficient step width to for concurrent ascent and descent. Alternatively to separate the ascent and descent traffic, either two sets of stairs are required or entwined spirals of double helical forms are used. Double helix spiral stairs are also used to meet a legal requirement to have two separate fire escapes.


The Pozzo di San Patrizio or St. Patrick’s Well is a historic well in Orvieto, Umbria, central Italy. It was built by architect-engineer Antonio da Sangallo, between 1527 and 1537, at the behest of Pope Clement VII, who had taken refuge at Orvieto during the sack of Rome in 1527 by the Holy Roman Emperor Charles V, and feared that the city’s water supply would be insufficient in the event of a siege. The well was completed in 1537 during the papacy of Pope Paul III. A central well shaft with two spiral ramps in a double helix, accessed by two doors, allowed mules to carry empty and full water vessels separately in downward and upward directions. The cylindrical well is 53.15 metres (174.4 ft) deep with a base diameter of 13 metres (43 ft). There are 248 steps and 70 windows provide illumination.

Pozzo san patrizio orvieto > Double helix spiral stairs for mules to move up and down to fetch water

Pozzo di San Patrizio Oriveto

Top of the well

Taff’s Well thermal spring is located in Taff’s Well, north of Cardiff, South Wales, UK. The spring emerges on the eastern bank of the River Taff. The spring is enclosed inside a well and stone building constructed in the 19th C. A brick built spiral staircase is incorporated in the inside of the well.

Taffs Well Thermal Spring Helix stair

Château de Maulnes in Cruzy-le-Châtel, Burgundy, France: the central helical stairs around the well, also used as a skylight.

The Well of Initiation located in Quinta da Regaleira, Sintra, Portugal was built 1904 – 1910. At the bottom of the well is seen the Rose of the Winds placed upon the Rosy Cross.

Sintra Quinta da Regaleira




Post 386 – by Gautam Shah 



Bricks are cast mainly from soils with high content of alumina and free silica. Though calcareous, chalky and high silica (fire clay) soils are also used for many special types of bricks. Bricks get the primary toughness due to removal of chemically bound water from the constituents of soil, oxidation of salts, and vitrification of silica matters. At temperatures above 300° C some of the constituents start flowing producing a glassy mass. This glassy mass and some of the oxides bind together all other material forming a hard mass. Later, on soaking the hydration of silicates and aluminate provide the extra strength. Over the years gradual carbonation of hydrated lime provides additional hardness. Colour of the brick is important criteria for surface finishing. It is influenced by contents of the soils, range and duration of burning temperature, ventilation system of the kiln, casting techniques etc.

Wall Old Grunge Brick Design Texture Vintage

Bricks variations of colours

Bricks variations of colours

Bricks are made from high alumina clays with a small amount of colloidal or free silica, but many other additives are used primarily to adjust the plasticity of the mass. Some of these additives are organic such as grass, hay, rice husk, which on burning impart porosity. Rice husks in addition provide siliceous substances which in combination with lime impart pozzolana like cementitious bond. Powder of burnt broken bricks is added to clays in place of free silica sand to reduce the shrinkage cracks during drying and burning.

Machine extruded hollow bricks

Bricks are variously permeable. Predominantly alumina bricks are more permeable than silica bricks. Under-burnt and low temperature fired bricks are more absorbent compared to over burnt and high temperature (refractory) bricks. Hand pressed bricks are less compact than machine-made bricks, and as a result absorb more water.

Building Rome Bricks Architecture Arches Italy

Hollow and perforated bricks are extrusion cast by machines, from very wet and plastic mass. Roofing tiles and facing brick tiles are die mould cast from slightly less wet mass.

Porous thermal brick

Bricks of exposed masonry surface, if permeable allow bacterial growth such as mould, fungi etc. on the surface. Soluble salts present in the clay, usually get decomposed during the burning, but immediately after highest temperature of firing. Substances like, sulphate of sodium, calcium, potassium and magnesium are formed due to presence of sulphur from the fumes of the fuels. These salts on contact with absorbed moisture, leach out on the surface. Most of the sulphates get washed away from the masonry surface, but magnesium sulphate does not leach out readily. It expands and cause cracks in bricks. Calcium sulphate though difficultly leached out settles on the surface to form whitish scum. Porous and rough brick surfaces are better for mortar adhesion than an impervious smooth surface of a very vitrified brick, Over burnt or highly vitrified bricks have very low suction capacity for mortar binding. Over burnt bricks are dimensionally deformed due to running of the mass and unsuitable for masonry work.


Next to the colour, texture and quality of the brick are important. A masonry surface is characterized by the brick colour, colours of the joints, and form of the joints. Jointing and pointing material for brick surfacing has to surpass the overall performance of bricks. High adhesion, low permeability and suitable colour matching, are some of the attributes of a good jointing-pointing material. Flushed, projected and grooved pointing, are used for brick work, of which flushed with string mark type of pointing is best. Unlike the projected or grooved pointing, flushed pointing does not retain dirt or water in its holds. The string marks are adequate guide path for any hair crack that may develop.

Brick masonry work Indian Inst of Management Ahmedabad, India


VELVET – Fabric of Luxury

Post 385 – by Gautam Shah 


Velvet sleeves Portrait of Sir Thomas More (ART by Hans Holbein (1498–1543)). Oak, 74.2 × 59 cm. Frick Collection, New York

Piled weaves are used to create textured fabrics. The characteristic texture over the surface of fabric is formed of Tuft or, loops that are cut or uncut. The piles are made from either or both warp, and web yarns. Corduroy, Velvets, Velveteen, Valour, Plushes are such piled fabric constructions. Few other materials, such as the suede, flocked fibres, have Velvet like a feel.

velvet ropes

Velvet is a fabric formed of three elements: ‘a structural warp, a structural weft and a non structural or supplementary warp’. There are two types of looms in which pile-velvet were produced. On a regular velvet loom, double layered fabric is woven, with piles interlacing both layers. After weaving the fabric layers are sheared and separated into two single cloths. The inner faces of the fabrics have cut piles. On a wire loom the piles are formed through looping the yarns over the wire. After withdrawing the holding wire a knife cuts the loop, producing the cut pile. In another option the piles are not cut. The uncut piles have own texture and feel. Often there are dual constructions where one set of warp and web fibres form a plain weave base, and another set of alternate web or warp fibres create piles. The piles may be cut or left uncut as loops.

Blue velvet dress of Diana, Princess of Wales


Velvet weaving originated somewhere on the far east side of the silk route. From here it must have been taken by the Arabs to Europe. The Persian and Hindi (India) word for velvet is Makhmal, literally meaning silky or smooth feel. Mughal and Safavid (Iranian) weavers not only exploited the properties of velvet but enriched it with gold and silver. They also dyed the fabric to dark and deep colours. In Europe, during 12th C. velvet found a base in Italian towns of Lucca, Sicily and Florence.

Throne chair of Stanislaus Augustus Warsaw


The cut-pile method of fabric surface forming is used in two other types of fabrics: namely, Velveteens and Valours. Velveteen is usually made of cotton or its blends. It has shorter and stiffer pile that lies flat. It is sturdy and durable but has poorer draping, and lesser sheen. It is also less denser and so used as craft or toy making fabric. Velvet is a very ancient fabric, whereas velveteen is of recent making. Velour is often called a stretch fabric. It is used as stretching over furnishing fabric for shaping purposes.

Velvet curtain – Tableau curtain from inside of the scene Wikipedia Image by Sémhur

Crushed velvet is produced by manipulating the fabric whilst it is wet. The manipulations include twisting, crushing, brushing, creasing and embossing. Creases and folds in the fabric can flatten the pile or make it lumpy. Devore velvet is a fabric treated with a caustic solution as a pattern, to dissolve the piles in select sections. Embossed velvet is created by heat treatment with a patterned roller. Panne velvet is a result of treatment that forces piles to lie in particular direction.

Devore velvet -burn-out sections on velvet Wikipedia Image by Libby norman

Velvet fabrics due to the one-directional weave and piles show a characteristic nap. The nap affects the colour perception from length and width sides. Due to the nap, the fabric feels smoother in one direction than the other. It is very necessary to align or orient the nap consistently for all uses.


Velvet, a piled fabric consumes lots of silk, and so is very costly. It is a light density and fragile material. Velvet is a method of fabric formation, and so can be used with many other fibres, such as cotton, rayons, acetate, polyesters, etc. Each fiber types or combination provides a different quality of velvet fabric. But it is the surface-feel that makes the fabric soft, smooth, elegant, cool to the skin and drape-able.


Silk velvet was a highly prized fabric, identified with wealth, power and prestige. Synthetic velvets made from rayon and acetate are cheaper but heavier and do not drape well. All types of velvets can be dyed with saturated deep colours, due to its unique fibrous surface.

Jewel box lining

Velvets are used in everything dresses, gowns, horse carriages, furniture, clothes, jackets, handbags, scarves, skirts and blouses, drape and wall coverings. Mughal used it for making Shamiana (tents) for parties. Velvets have been used stage curtains. Velvet fabrics are opaque, and due this reasons are used as background for exhibit of art-pieces shadowboxes, jewellery boxes, photo boxes and lining the coffins.


Diwan i Khas Red Fort Delhi Shamianas



Post 384 –by Gautam Shah



Additional work-power for greater task capacity has been a need since the beginning of civilization. First effort in this direction was the wheel for easing the movement. But to push or pull greater loads large number of human beings or animals were required. To concentrate such massive power deployment, ropes (for pulling) and structures (for pushing) were required. The wheels, ropes and structures were employed to move loads on level grounds or lift them against the gravity. Other power needs were more stationary such as moving the potters’ wheel or the grain grinding stones.







The power concentration was aided by series of pulleys arrangement, and distanced leveraging. Power movement continuum was also devised by flywheel system. Water and wind were harnessed for power by Roman times. Water and wind were unpredictable or intermittent sources. For days the mills could remain useless for grinding grains or minerals. Till the end of middle ages, the size and scale of the mechanical apparatuses were capable of offering power equal to few horsepower whereby a wind mill could draw water from an average well, or a water wheel could turn a grain grinding system. These were mostly made of wood structures and even moving wooden parts. Iron parts were rare in rural areas. Both, wind and water system required possible production facility to be located near the sources, usually away from urban settlements. Everywhere rivers were diverted, reservoirs built and pipes or channels laid to operate the water wheels.


There were number of industrial processes that required consistent power, such as forging, spinning, weaving, grinding, usually supplied by human labour and animals. But by the beginning of 18th C steam turbines began to offer uninterrupted industrial power in urban locations where better transport connection brought in fuels like wood, charcoal, coal etc. The animal, water and wind powers, yet remained economic options till the beginning of 20th C.


The Burden Iron Works on the Hudson River and Wynantskill Creek in Troy, New York area is an example how the quest for power manifested in super-size water wheel plant. It has been acknowledged as one of the most powerful water wheel power plants. It was designed in 1838-39. It was 18.50 metres in diameter and 6.70 metres wide. The water wheel weighed 250 tons and could produce on average 500 horsepower when spinning 2.5 times a minute. The wheel was called ‘the Niagara of water-wheels.’ In 1851, it gave place to a larger one (the present 1,200 horsepower). The wheel was like a cycle wheel 0f suspension type with rods forming the tensile spokes. It was made of iron, except for the drum (soling of the wheel) and its buckets. To make the water wheel viable for all seasons, Burden formed a system of reservoirs along the Wynantskill Creek.




HEARING and interior spaces

Post 383 – by Gautam Shah



Hearing reveals multiple facets of architectural spaces through a very comprehensive experience. The experience is not focussed like vision, but substantially includes many convergent audio ‘effects’. This effects have clueless or orientation-less feel. Visual knowledge is more metrical compared to hearing which is abstract.


A normal person relies more on directed visual clues than diverse audio feeds. This is because visual information can be perceived and processed faster, whereas the audio cognition needs sustained understanding of the space making elements.

abandon_alley_architecture_black_city_corridor_dark_derelict-1358067.jpg!dThe audio information in a space is made of: 1. Direct sounds, 2. Reverberated sounds from different distances, surfaces and directions and, 3. background noises that enter the space. The hearing becomes more complex, when sounds get mixed to depress or enhance certain frequencies.


The space making elements, such as materials and their surfaces, the shape and the size, format the space hearing experience. This was realized from primitive times. Architectural spaces were exploited (rather than designed a fresh) for the hearing related inherent space facilities. This was possible with sporadic success. Acoustics for new spaces were always an unpredictable exercise.


Continuous use of known spaces, sizes, and shapes give a predictable audio experience. Religious buildings, amphi theatres, meeting halls, were such oft repeated works. The visual and tactile knowledge of the space helped mould it for hearing. Opera and concert spaces were fine tuned for such combined sensorial experiences.



Opera and concert halls over a period have fashioned the architecture of sound transmission exploiting the shape and size, beyond the surface qualities. Parabolic ceilings, inclined walls, convergent or conical forms were involved in interior articulation of the space. Even then within a space there were great many locally variegated experiences. A church, concert hall or assembly hall always had few pockets of poor hearing.


In all large spaces the spatial experience was moulded by direct and reverberated sound synchronized with relevant visual clues. Greek and Roman theatres were designed to bring the audiences closer to the stage so that audio-visual experience would become one. These were reinforced with loud and emphatic dialogue delivery, use of extra ordinarily flocked dresses and highly articulated postures and gestures. These traditions also continued in dramas, operas and other musicals. The techniques were, however, not freely applicable in sombre religious ceremonies.



For Peter Zumthor the Interiors are like large instruments, collecting sound, amplifying it, transmitting it elsewhere. That has to do with the shape peculiar to each room and with the surface of materials they contain, and the way those materials have been applied.’ Corridors or passages are considered eerie places, not just due to poorly lit and unexciting architecture but the sound quality.

glacier-and-hiker-725x482Hearing nothing is like hearing through sea shell that re-transmits all sounds baffled by a wall and its labyrinth form. The Pantheon or cave recall this ‘absence or absorption’ of sounds. Architectural acoustics was once about managing the outside noises and inside sounds. The former was solved by isolation from surroundings, and the later by spatial modulation.Trees barriers

Modern technology of hearing, deals with the presence and absence of sounds, in the work places. One may not desire to eavesdrop a colleague talking to another co-worker or a wife at home. In highly insulated work space the complete absorption of such noise is as much a problem as the inability to suppress such sounds. These are now managed by adding additional sounds (white noise) through special type of speakers. The speakers output sounds in set frequency range to cancel (sound making – white noise) out the irritant sound presences.






Post 382 ⇒   by Gautam Shah 


Understanding the human body temperature management is very important for Interior Designers. It tells how space and human body interact and in the immediate term regulate the comfort and productivity. The persistent equation between the space and human body also decides the well being of a person.

Climate affects our body system very profoundly. The climatic effects are primarily sensed by the skin. Five types of sensations are involved with the skin: The Touch-Pressure (mechanic-o receptors), Cold-Warmth feeling (thermo receptors), Pain and Itch. Cold is a consequence of contraction of blood vessels and warmth is felt due to dilation of blood vessels; both are felt by the same receptors.

amphibians have poor or no temperature control mechanisms

Our body functions as a thermo equilibrium system. It continues to strive a state of balance, by many different body mechanisms and spatial-environmental interventions. In the shorter period human body may endure or adopt to certain abnormal conditions. Frequent such shocks cause side effects which may be realized in a different form and at a different time. The Optimum or Comfort level temperature depends on the level of acclimatization.

Snow Monkeys Nagano Japan

The thermal bearing capacity has upper and lower limits. The pain occurs at the upper limit of 52° C /126° F, and has a lower limit of 3° C / 37° F. In certain acute work conditions like mines, metal smelting plants, cotton spinning-weaving plants, cold storage, the efficiency or productivity depends on the endurance level, adaptability and duration of exposure of the body.


Human body generates heat through basic three processes.

  1. Conversion of food matter into useful energy is a continuous heat generating process.
  2. Muscular activities like even sedentary work or sleeping, are heat generating processes.
  3. Certain infections and dysfunctions within the body, elevate or lower the body temperature by extra ordinary rate of heat generation, or weakened heat- dissipation, mechanism.

Human body utilizes only 20 % of all energy being generated by the nominal body processes, and the rest 80 % is surplus heat. The body however gains or loses heat with environmental interactions. All the surplus heat generated within the body and the excess heat gained from the environment must be adequately managed.

Human body gains heat from the atmosphere, and also dissipate excess heat to it, to maintain thermo equilibrium. Heat loss is accelerated by several body functions like perspiration, high transfer of heat to the skin by increased blood circulation (vaso-dilatation). When these prove to be insufficient, sweating occurs. In hot climates the heat loss rate is lower due to unfavourable atmospheric conditions.

Body can manage to lower the heat by lowering the metabolic and by reducing the muscular activity. But both of these require some time to take effect. On immediate basis when the heat loss is not balanced with heat gain, the `heat stroke‘ occurs. In cold climates the heat loss is higher, so heat balance is achieved by conservation of heat and by appropriate heat gain. Heat production is raised by certain reflex secretions (adrenaline, thyroxine), higher intakes of food (increased metabolic activity). Reflex shivering (muscular exercise) and with sufficient insulative protection the heat loss can be controlled. The body may control the heat loss by vaso-constriction (lower blood supply) and depressed sweating. A person exposed to a constant high rate of sweating and permanent vaso-dilation can have lots of physical strain with loss of work efficiency.

High heat environment -long term exposure

The human body maintains an average temperature of 98.4° F / 37° C (ranges between 31° and 34°C). There are many minor variations in body temperature, which are considered normal. Body temperature is lowest in the morning, and highest in the evening, within a range of 1.5° F / 1° C. Infants have a very imperfect mechanism for regulation of body temperature. A fit of crying may elevate and a cold wash may lower the body temperature. Aged persons have a low metabolism and so maintain a lower body temperature. It takes much longer for an aged person to gain or dissipate body heat. Female body temperature is slightly lower than Male.

The type food one takes affect the body temperature. High protein foods increase the body temperature. The act of ingestion and food digestion, both raise the body temperature. Exercise increases the body temperature, because only 25 % of muscular energy is converted into mechanical work, rest comes out as body heat. Many physical, chemical and bacterial agents disturb the heat regulation mechanism and cause fever. These may be due to increased heat production or reduced heat loss, or both.

Colder climate Bed paraphernalia

In reptiles and amphibians a heat regulation mechanism is absent. Their body temperature rises or falls with the atmospheric temperature. Hence they are called cold-blooded animals. In abnormal temperature conditions they regulate the body temperature by suitable habitat. In winter they go deep into burrows or in hibernation (minimize the metabolic heat generation). Mammals and birds are known as hot blooded creatures, because the heat regulation mechanism is well developed, and they are able to maintain a level of body temperature.

Warm climate dwelling

Our life styles reflect culture of the place, which in turn is our response to the environment. The heat management of our body is effected by the type of food, frequency of intake, volume, proportion of liquids, the rest (siesta) periods, the daily work-rest cycles, clothing, form of our habitat, types of furniture and furnishings.

Very warm exposure

Heat management occurs through Four routes:

1 Radiation: Radiation mainly occurs when there is a difference in temperature on opposing surfaces. As long as temperature of the opposite surface or object (sun, fire, radiators) is below skin temperature, the body can lose heat by radiation. But once it reaches equilibrium occurs, body will rather gain heat by radiation.

2 Evaporation is controlled by the level of humidity in the air. Level of humidity is in turn affected by temperature of the air and air movement. It is also depends on the existing proportion of humidity. Body dissipates heat through evaporation by perspiration, sweat and exhalation of air. Dryer air encourages faster evaporation. Evaporation can occur if air has velocity and appropriate humidity (low). Even in case of very high humidity conditions a high velocity air can remove the humidity.

3 Convection occurs when the air in the vicinity of skin becomes hot, expands, decreases in density, and elevates to allow cooler air in its place. The rate of heat convection from body depends on the difference in temperatures (skin & surrounding air) and rate of air movement. When the convective process is inoperative and radiation heat gain is positive, the body can maintain the thermal balance by evaporation.

4 Conduction depends on the difference between the body temperature, duration and extent of the contact.

Average heat exchange between Human body and Environment are of following order.

  • Radiation (60 %),
  • Evaporation (25 %),
  • Convection and Conduction (15 %).

KITCHEN and its shifting position

Post 381 – by Gautam Shah 



Kitchen as a space module, over the years, has been shifting around the dwelling. The shifts have occurred due to technological changes inside and outside the kitchen. These compulsive changes, have altered the nature of all other units of dwelling, except the bedroom. The interrelationships between the units of dwellings have been reset many times. Some new ones have become evident, whereas others have separated, merged with others, or just perished.

x Old Stone House kitchen

The kitchen is an intensive activity area, and so in comparison to the entire house, its dependence on outside resources is more acute. The perimeter of the kitchen thus becomes the prime location of touching the outside connections. A kitchen can never be a centric place in the dwelling, though a hearth was such a facility. The outside connections have occurred due to supplies of fuels, commodities and water, disposal of effluents and other wastes, ventilation for replacement of air and moisture, and view out as a relief from long duration occupation.

Werdenberg._Schlangenhaus._Ground_floor._Kitchen_-_010A ‘Kitchen’ consists Four main zones, storing, food processing area, cooking zone, and dining area. There could be other smaller identities such as fuel storage, water storage and kitchen utensils cleaning, laundry area, bathing area (in some ages and cultures), servants’ area (sleeping-resting). All these could be within an architectural space or in segmented form. The kitchen has been grounded or placed as a dungeon. In urban centers, this arrangement has not been possible in multi floored dwellings. Kitchens in Roman apartments on upper floors (such as on third or fourth floors) were not workable. Here the water, fuel and commodities supplies were difficult and disposal of solid waste more problematic. Romans relied more for foods on bakeries located at ground floors and for bathing used public toilets. The Parisian apartment or London raw house kitchens opened to backyards, not a place worthy to open out, through a window or door. In both types of cases, supplies were difficult to manage.

Roman Kitchen

Fuel and water supplies due to the bulk, and effluents and solid wastes have been irritants for kitchen arrangements. Every technical innovation, such as compact and high efficiency fuels, piped supply of water, drainage system, chimneys, glazed windows, has been readily accepted.


The dining, wherever possible, was first to be separated from the smoke-odour filled and soot-covered kitchen. The kitchen-dining could stay apart wherever servants were available and affordable, or had to be adjunct spaces. Similarly cloth and utensils washing became adjunct spaces. Bathing, which was part of the kitchen in colder climates, moved away.

Villa Rustica Ahrweiler Küche der Mansion

Villa Rustica Ahrweiler Küche der Mansion


A kitchen gradually became increasingly dependent on the outside world as supplies became diverse and more frequent. Urban kitchens depended on fresh and day to day supplies that were partly processed. These reduced the size of food processing area, wastes volume, fuel requirements, manpower needs and time involved in cooking. With smaller spatial requirements or more attuned space arrangement, the kitchen became a place to participate with a maid then delegate it to the maid. This also resulted in better recipes (rational processes) and quality of food.


The participation in cooking and related processes in a cleaner kitchen brought back the dining (at least breakfast, quick tea) to the kitchen. Participation by various members of family has seen many different trends. The modern age has offered outside work opportunities to women, resulting in much more intense sharing of the kitchen related responsibilities by other family members. The trend has been supported by kitchen design, gadgets, feeder and other services, pre-processed foods, and most importantly the fast food joints restaurants, and work place catering.