POST 730 -by Gautam Shah



2 INDOOR AIR ( 20May2014)

8 CLIMATE and BUILT-FORM (5July2015)
12 173 INDOOR HUMIDITY (18May2018)
14 Temperature related Comfort parameters for Interior Design (20Apr2014)

15 PASSIVE VENTILATION in Buildings (3July2014 )
16 MICRO VENTILATION in Buildings (8March2016)
19 158 DRAUGHT (draft) AIR MOVEMENTS (28Apr2018) ttps://
21 49 Indoor Air Pollution (3Dec2017)

24 BMR and BODY TEMPERATURE (5Oct2018)
25 CLIMATE and our BODY (26Jul2016)

26 CLIMATE and CHANGE (10Aug2014)
30 DEALING with ENVIRONMENT (10Jan2015)
31 WINDOWS and VENTILATION (20Dec2014)


Post 680 –by Gautam Shah


37th Annual Yokota Striders Frostbite Race

BMR: Basal Metabolic Rate is the amount of energy (metabolism-calories) per unit of time that a person needs to keep the body functioning, at rest. The ‘rest’ or body sustenance functions include breathing, blood circulation, controlling body temperature, cell growth, brain and nerve. The basal metabolic rate accounts for about 60 to 75% of the daily calorie expenditure by individuals. About 20% of energy expenditure comes from physical activities and another 10% from digestion of food. It is influenced by several factors, such as the age, gender, degree of acclimatization, posture and state of health. The primary organ responsible for BMR regulating metabolisms is the hypothalamus.


Our body functions as a thermo equilibrium system, with upper limits of bearing is 52° C, and lower limits of 3° C. A body may endure or adopt to certain abnormal conditions for a period of time, but there may occur side effects. The side effects may be realized in a different form and at a different time. In certain acute work conditions like mines, metal smelting plants, textile plants, cold storage, the levels of efficiency or productivity depend on the endurance level and adaptability of the body.


The human body has many minor variations, but an average temperature of 37° C. Body temperature is highest in the evening and lowest in the morning (+or- range of 1° C.) energy expenditure of the body is different for endothermic animals and fish or reptiles. In reptiles and amphibia heat regulation mechanisms 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 like burrowing and hibernation.



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. High protein foods increase the body temperature. The act ingestion, food digestion and exercise raises the body temperature. Atmospheric conditions like, temperature, humidity and movement of air, affect the efficiency of heat exchange from the body, and so the body temperature.



There are three types of heat generating processes in the human body. Conversion of food matter into useful energy, Muscular activities, and Certain infections and dysfunctions within the body, elevates or lower the body temperature by extra ordinary rate. 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.

Africa School Life Joy Happy Students Literacy




Post 670 by Gautam Shah



Openings need additional shading systems primarily because these are thin and more translucent in comparison to any other structural barrier systems, like walls, floors or roofs. Additional shading systems are preferred because the needs are for small period of time, part of a season, occasion or location. The needs for a shading device are people, culture or locality specific. The openings are used for outward and inward view, illumination, breeze and air change. And shading devices achieve needs by blockage, filtration, reflection, redirection or delays.


Opening systems like Gates, Doors and Windows have three distinct zones: The exterior zone deals with environmental aspects that are spatial extensive, directional, temporal and seasonal, The interim section constitutes the body of the opening, and so its depth is the operative element. The interior segment is in the personal domain of the owner-user, which makes Interior shading devices easy to install, manouevre, change, with variable yet very precise control over the functions. Interiors shading devices are also visible from outside and so some conflicts of approach to design are inevitable. In most likely scenarios the architect is a different person than the Interior designer, who may or may not confirm to the theme of architecture.


Shading Devices with openings are of many different types. Different types of shading devices improve each other’s functions, often duplicating it. There is a strong demand to rationalize the system with fewer elements, by way of integration, removal of duplication and redundancy. Shading devices offer micro tuning of the environment, catering to local requirements, provide occasional variations and satisfy the urge for personalization.


● External shading devices are architectural provisions, with varying levels of integration. There is an overwhelming regimen of the building style, location, orientation and shape-form. The provisions are so confirmatory that user is not allowed to make any changes. The provisions, though occur as fixed devices and as manipulable systems, no spatial relocation is allowed.


External shading devices are of longer lasting materials as these have to bear the elements of environment like Sun, rain, heavy storms, snow, atmospheric pollution. These are termed architectonic element due to the match with architectural language.



External shading devices are very effective, as they intervene before the radiation, rain, wind etc. enter into a building shell. Such devices de-rigueur have universal design for all faces and floors, but are affective differently at different times of the day or season.


● Interim shading devices have thickness as the key factor, and are usually thin. Interim systems could have partial spread or have options of folding, collapsing or demounting. These are frugal and likely to be a single purpose entity. Interim shading systems are often spatial provisions of vacuum or gas filled cavities.


● Internal shading Devices occur in a user domain and so are preferred for the ease of choice, installation, change and manipulation. These provide variable yet very exact control over privacy. The internal shading devices are housed in a protected environment so can be delicate, lighter in weight and occupy a very small thickness.


Internal shading devices are multi layered to serve diverse purposes, and offer several choices of spread or placement. The space between different layers is intentional, to work as a metaphysical barrier. Internal systems also serve purposes beyond the shading, like sound and thermal insulation of the interior space. These also provide a tactile (soft) surface, colour and textural effect in the interior space. Interim shading devices filter and diffuse the light in inward and outward directions.


Internal shading devices are predominantly of soft materials such as fabrics, films, sheets, flexible materials like mats, nets, tapestries, or stiffer materials such as reeds, wood slats, etc. Thin and pliable materials allow the assembly to collapse, gather or roll up. Glazing materials offer largest variety of surface treatments, by way of manufactured constitution, integrated and applique surface treatments. Glass surface treatments now include application of films, texturizing, metalizing, micro (nano or molecular level) engraving, enamelling and colouring.


Shading devices such as Venetian blinds or vertical louvers are not very effective on the internal face of the opening, as the solar gain has already been admitted into the interior space. But interior shading devices offer glare control, and visual comfort. An internal shading device reflects back part of the radiation, but latent heat remains within the interior space.

Shading Devices are single or multi layer systems, acting as a composite or assembly of individual skins. The layers have prearranged sequence, so access to an inner layer becomes difficult. Some can be collapsed or removed. Layers form a planer element with some materials plus cavities as the substantive body.

Interim Layer of masking tower-stairhall-300-x-225

Additive or mounting systems are used as optional or occasional facility like storm shutters. Collapsible or folding systems require a volumetric space for parking or resting, which reduces the net area of opening. Pseudo or pretentious shading devices are in the form of furniture elements, furnishings, panelling, partitions and other architectural devices.


Thermal management by shading devices: These are designed to take optimum advantage of seasonal angles of a solar incidence. The solar gain occurs primarily in reference to the plane of the window, so an alternate method could be to have a variable plane of the window, but that may not be an appropriate architectural style. However, external shading devices keep the glazing surface in shade to cut off the direct solar radiation.


Vision management through shading devices: Shading devices as subsystems divide the view out or inwards by framing, masking, modelling. The visual scape is altered through the sill and lintel level and shape, pattern configurations, quality of glazing etc.


Safety security with shading devices: External shading elements maintain or reduce the size of opening, and so become integrated latticed barriers for safety and security against height related hazards.


SUPPORT SYSTEMS -Issues of Design-22

Post 669 by Gautam Shah



We need supports to move, stand, or even do nothing. We use the support for gaining, sustaining or relieving various biological conditions of the body. We need, physical as well as abstract, supports. We need supports inside our places of inhabitation, and beyond it. We explore our environments for natural supports, and configure supports as we create our habitats.


Primary supports are required for getting in-out, conducting tasks, closing-opening and shifting the utilities. Supports are also used for expression and communication. Supports govern the reach and work capacity of a person. Supports allow and enhance movement of the body limbs and parts, in wide range of spatial occupations and conduct it at a required pace.


Built-forms, amenities and facilities offer a complex set of configured supports. Supports are required to initiate an action, for work towards or away from the gravity, overcome impedance of friction, bondage etc., for swaying and stopping it and absorb the bounce-back forces of reaction. Supports help change the body postures for physiological relief, breathing, metabolism, respite from tedium and consistency.


Support systems are universal, used by persons of different stature, abilities, age profiles and mental conditions. Supports occur in one continuum, employed in unique sequence of activities. For these two reasons, some optimal needs must be realized.


Amenities and Facilities offer physical and abstract supports. The physical supports as they really exist, we rarely use them. The physical supports through their presence provide assured certainty and adequacy of performance, safety and security. It is psychological reliability that the supports are available, when and where needed. Abstract supports do not exist, but are rather conditions that restrict one to take certain actions. These are socially acknowledged thresholds. Such metaphorical systems also regulate the expressions of the body.


The supports are required for facilitating Macro movements of the body, like shifting the body or changing the posture whereas Micro movements help in gestures, communication and expression, and to realign the physiological pressures.


In all work processes, brisk or sedentary, one needs the ability to freely reposition the body. Such movements are postural ones, like the movement of limbs, neck, switching the weight over legs, or wriggling over the bottom. Others are gestural (twitching of lips, eyebrows). The postural or gestural changes occur with supports. These are, access height of the amenity, body position and related reach and work ability, familiarity etc. Assurance of a support allows one to take deliberate risks.


Body movements endow new work capacities (reach, spread, productivity) besides removing the tedium. Such dynamic posturing increases cognition of happenings around us and encourages concentration by stimulation of muscles, blood circulation, and neurochemical processes. Too many body changes may seem distracting to others.


Balancing the body

We continuously sway our body due to internal causes (breathing, metabolic activity), and for external reasons (like turning head while observing and communicating, for keeping garments in order). The sway invigorates our body and greater participation in the world around us. For such minor swaying no physical supports are required to initiate or terminate it.


The postural changeability is both a physiological adjustment and a psychological expression. It is reflected in anxiety and boredom. Postural discomfort also occurs due to inadequacies of utilities. Utilities are exploited (misused) for fidgeting. Fidgeting is now accepted as a mode of tackling and learning. Intentional postural incongruities are natural while executing novel and complicated tasks. But postural stillness does not last very long while handling vibrant conditions.


Exposure of postural discomfort and related restlessness, if amplified, can become very embracing. Designers need to include supports and barriers for fidgeting to flourish but regulate its exposure. Postural discomfort at some level is unbalancing force and a nearby support is required.

Receptionists are intensely observed persons. This is annoying when waiting seats are in front, a reception table is at eye level and its front is open and no other interests in the space. Similarly ‘open desks’ on stage or in conference rooms, if open at leg level distract the viewers.


Once, our work tables were ‘wall mounted’, to source various services (drainage, power, structural support), but then concept of island work stations offered multi-directional posturing and access. In offices the open plans were too static. The personal table top computers were too fixed for fidgeting around. The Laptops with wireless data transfer systems and cloud storage not only allow micro body movements, but also posting in variable locations.

Designers are offering amenities and facilities that are not very ‘comfy’ but with ‘bearable discomfort’. That causes, little physical inconvenience, to infuse reach, balance, transitions extra ordinary perception.


Indian offices, once had stools for peons. The wide foot print (legs tapering outward) offered a stable structure but its small sized seat and taller height, were unnerving, keeping the person alert and ready to standup. Similarly tall bar-stools also do not allow one to settle but allow freedom of movement. Aged people (and pregnant ladies), to get up, derive support from handles and harder, taller and a flatter seat, things contrary to these conditions make life difficult.


The support systems are required for Active or Passive movements.

Ο Free active movements are used by a person to overcome the effect of gravity, for example, rising from lying to seating position.

Ο Resisted active movements are used by a person to overcome the effects of a manually or mechanically applied force, for example, lifting a load, closing a door, using a knife and fork, or digging with a spade.

Ο Assisted active movements occur with the help of another person or apparatus, like mother assisting a child or by using a chain or rope.

Ο Assisted-resisted active movements are dual efforts. First part of the movement assistance is required to initiate an action, but the other part uses resistance to control the action.

Ο Passive movements are those produced by an external force during muscle inactivity. All joint movements can be performed passively by manual means.



This is the 22 nd (continuation of old series -new beginning) article on ISSUES of DESIGN



Post 648 -Gautam Shah


Passive ventilation sustains good quality of air in interior spaces. It works on circulation or movement of air without the use of power utilities. It relies on principals of source management and dilution, rather than any filtration. Passive ventilation is substantially based on the quality of built-form and to a smaller extent on immediate surroundings. It is a very important method of adjusting heat and moisture in Hot-arid and Hot-humid climates. The quality of air is determined by temperature, moisture content, presence and proportion of ‘other’ gases and airborne particulate matter. The quality of air has important bearing on our body. A body may endure or adopt to certain abnormal conditions for a period of time but there may occur side effects. The side effects may be realized in a different form and at a different time.


Passive ventilation relies, as much on external or macro conditions, as the interior spatial lay. It is based on three factors:

  1. Air movements due to the differing pressures and temperatures and the buoyancy forces that result across a building and its surroundings,
  2. Location of tasks and activities that support or hinder such patterns of air movements, circumstantial and designed apertures in the building shell.
  3. Factors that define the ventilation in a building are, space-profile (section), base levels of inward-outward nodes of ventilation, nature of surroundings and neighbourhood, sill level, depth and its profile-shape, task-intensive operative plane and its volume, and constraints enforced by elements such as size and shape of external overhangs.


Passive ventilation occurs with Two major operants.

Differential air pressures are formed by wind movements in the immediacy of the building, the pattern and size of the buildings scheme and individual components of the building. Air movement also occur as a buoyancy effect caused by the temperatures of surfaces and surroundings near the wind-ward and wind-off sides. Air pressure difference occurs, across buildings’ interiors and exteriors, across the openings and temperature of surfaces and surroundings, near the windward and wind-off sides. Entry and exit point for air, though continually shift around due to the changes in pressures.

Desert City Oasis Town Ait Ben Haddou Oasis

Temperature differential depends on the direction and inclination of sun, climate, seasons of the year, local massing of the shadows, surface materials, vegetation, water bodies, and presence of heat evolving entities. Dark surfaces and thin body objects warm up very fast and begin to radiate the heat, creating local heat related buoyancy in air.


Ventilation requirements vary depending on whether one wants to gain or lose heat, add or subtract moisture, dilute or remove ‘other’ gases and airborne particulate matter contaminants. Ventilation needs change depending on, distance of space occupation from the inlet-outlet for air, functional use of space, types of tasks, work-schedules, crowding in the space and presence of heat evolving means (hearths, machines, etc.). One important aspect is the feeling of air movement near-over the body. It depends on several factors such as air velocity, fluctuations in air velocity, temperature of air, and personal factors like overall thermal sensation and activity level. Even for the same person, sensitivity to air movement may change from day to day.

635px-Wall_Decoration_at_Kesava_Temple_in_Somanathapura_retouchedDraughts (Draft) are very low velocity air movements. These are not always perceptible, as they do not cause any sensation of pain or pressure on skin. Draughts are more felt due to air pressure thresholds near cracks and such leakage points in small and enclosed spaces. Draughts, however, help in convective heat exchange, evaporation and dilution of pollutants in air. Draughts cause localized cooling or heating of sensitive organs of our body.

Breeze or low to medium velocity air movements generally affect only local areas. Breeze does not let airborne particulate matter to settle down. Skin sensation can be avoided by appropriate screening and deflection of the breeze. Since breeze causes effective pressure on skin, with very immediate and very perceptible change sensation.

Winds are high air velocity movements of air affecting larger regions. Winds raise particulate matter in the air, cause rapid change in level of humidity and often cause discomfort due to high pressure sensation on the skin.

1 Stone_Roofing_House_-_Palchan_-_Kullu_2014-05-10_2507

In hot and cold both types of climates people often close all the openings to reduce the air movements and thereby control the convective heat gain or loss. Turbulent air velocity is less comfortable than a Laminar air velocity. Turbulent air movement achieves a better mix of air whereas laminar helps in greater displacement of air mass. This is the reason why in hot arid climates small size openings are used to create turbulence or a viscous flow, and in hot humid climates the body level openings of horizontal nature create a laminar flow to displace the humidity.


Passive ventilation occurs through macro and micro openings. Macro or formal openings (doors, windows, gaps etc.) are designed with a characteristic size, shape, passage section, adjunct elements on internal and external faces, and occur close to the location of need (for ventilation). Micro openings are circumstantial, and are much smaller in size like cracks, crevices, gaps or apertures. Micro openings offer a passive and consistent ways of managing comfort in enclosed and semi-open spaces. These manifest as intentional gaps, unplanned crevices and cracks of structural stresses. Both, macro and micro openings can be broadly be classified by their locations.


  • Roof level openings are such as in the thatched and country tile roofs, loosely laid roof slates, stone sheets, or intentionally placed micro passive vents such as lattices, chutes, hoppers, etc.
  • Upper section openings in walls are such as the unpacked ends of corrugated sheets or roofing tiles, ends of purlins and truss and eyelets or oculi like holes and lites in gables.
  • Other openings manifest as doors, windows, cut-outs, chowks, in joinery, leaky fitments, ajar shutters, door bottom space, peep-holes, latticed constructions such as of woven mats or fabrics, louvered openings, crack or fissures in building elements, expansion joints, unsealed joints, etc.

Movement of air through openings encourages evaporation and increases cooling in the interior space. In dry arid climates dwellers locate their activities in the strongly directional air movement formed by small and deep-set openings. Deep-set openings also increase absorption of heat in the mass of the structure. Simple passive cooling devices such as water wetted grass mats or fountains help cooling. Outside air has lesser moisture (except during raining conditions) then indoor air, so any level of ventilation, dilutes the interior humidity level and adds to the comfort.

620px-AlfedPalmersmokestacksAir borne particulates arrive from outside sources like heavy vehicular traffic, polluting industry (mines, thermal power plants, mineral grinding plants, in the vicinity, or sand storms, and internal sources like cooking or craft fuels, and processing materials (grinding, spinning-weaving). Outside particulate can be controlled by changing the ventilation gaps to different location or elevation. Filtration screens occupy more then 60% of opening area, and much lesser due to frequent choking. Dynamic screening like water bodies or sprays can be useful, but costly and perhaps beyond the concept of a passive device. Non turbulent wind flow helps in keeping the particulate matter to lower sections.

Moisture control in interior space occurs by dilution, greater air movement and siting management of moisture generating amenities. Isolation of cooking, washing, bathing areas in dwelling is a common practice in hot-humid climates.

Quality of indoor air mainly depends on the external circumstances. The ‘feel-good aspect’ in a tropical climate (hot-arid or hot-humid) zone is not only regulated by the obvious temperature, rates of movement (pressure) and the moisture content, but also by the level of fouling of air. Some experts have claimed that air quality of a room is chiefly determined by its CO2 concentration. In tropical buildings concentration of CO2 and other gases is not a critical factor, as numerous openings and micro gaps remain substantially open. Location of cooking area is a segregated entity or an outdoor activity, and like cold climates no interior fire places.




Post 588 by Gautam Shah


Micro ventilation is a very important passive method of adjusting heat and moisture for Hot-arid and Hot-humid climates. It is based on three factors: Air movements due to the differing pressures outside the building, like windward and wind-off sides. Buoyancy forces that results from temperature across the buildings interior and exteriors, and Pattern of circumstantial and designed apertures in the building shell. Micro ventilation relies more on external or macro conditions of the locality, but needs appropriate interior design.


Micro ventilated Traditional Konkan (Hot-arid) region houses, India Wikipedia image by PP Yoonus

Micro ventilation ensures that AIR enters or leaves a space through cracks, crevices, gaps or apertures, diluting the interior contaminants and adjusting the temperature and moisture. It is one of the easiest and consistent ways of managing comfort in enclosed and semi-open spaces. Micro ventilation systems are of vernacular design and time-tested solutions that have come down from one generation to another.

1 Stone_Roofing_House_-_Palchan_-_Kullu_2014-05-10_2507

Entry and exit of air occur due to Differential Pressures along a point to point paths of air movement. The operative pressure is governed by both, the size and shape of the buildings layout scheme and individual characteristics of the building such as shape, size, height etc. Air movement occurs as a Buoyant Force due to the temperature difference across buildings’ interior and exteriors in general, and across the openings in particular. The air pressure is also affected by temperature of surfaces and surroundings, near the windward and wind-off sides. In a building micro openings are, circumstantial and designed. The micro openings are very much smaller in size in comparison to buildings’ formal openings like doors, windows, gaps etc. Micro openings yet have a characteristic size, shape, passage section, adjunct elements on internal and external faces, and their closeness to the location of need (for ventilation). The circulation or movement of air is affected, by the space profile (section), the task intensive volume and its datum, levels of ventilation (import-export) nodes, the hindrance by elements such as size and shape of external overhangs, the sill depth and its profile shape.

Roof Ventilator

Roof Vents

Micro ventilation operates as outside air has lesser moisture (except during actual raining conditions) then indoor air, so any level of ventilation, dilutes the interior humidity level and adds to the comfort.


Grass-thatched roof > Wikipedia image by MBAGroup6

Micro openings are circumstantial and designed, as casual parts of the buildings’ structure, components and systems (including openings), or formal or passive elements. But broadly these can be classified by their locations. Movement of air also encourages evaporation and increases cooling in the interior space. In dry arid climates smaller and deep-set openings create a strongly directional air movement allowing dwellers to locate their activities suitably. Deep-set openings also increase absorption of heat in the mass of the built-form or add simple cooling devices such as water wetted grass mats or fountains.

roof tiles

ROOF RELATED GAPS are such as in the thatched and country tile roofs, loosely laid roofs of slates, stone sheets. Formal devices include vents such as lattices, chutes, hoppers, etc.

GAPS IN UPPER SECTION OF WALLS are such as the unpacked ends of corrugated roofing sheets or terracotta tiles, ends of purlins and trusses when not sealed, and eyelets or oculi like holes in gables.

OTHER GAPS are circumstantial that exist in and around openings such as doors and windows, as loose joinery, leaky fitments, ajar shutters, door bottom space, peepholes, openings without shutters (gaps), latticed constructions such as of woven mats, fabrics, or louvered openings, crack or fissures in building elements, expansion joints, unsealed joints, etc.


Cadjan House Myanmar > Wikipedia image by Michael Coghlan Adelaide, Australia

Micro ventilation requirements inside a building vary depending on the climate, season of the year, use of the space, tasks, work-schedules, crowding in the space and presence of heat evolving means (hearths, machines, etc.) The ventilation requirements also depend on the amenities used for conducting the tasks.


Krishnapuram Palace Kerala India > Wikipedia image by Appusviews at ml.wikipedia

In many old buildings the micro ventilation system is almost sufficient for dilution of fouled air. Micro ventilation of the building is further exploited by life style settings attuned to the air flow movement paths, pressure gradients and qualitative variations at different locations and time schedules. Task activities are continually shifted around to match the seasonal and diurnal variations.




Post 465 by Gautam Shah


Changes that we experience in things around us generally happen because of various effects of the climate. It affects all beings and things in small measures. A climate is the most pervasive, consistently variable and largely indeterminable phenomena. Climate conditions, our comfort and survival. It builds up all our experiences. It provides the dynamism that is Nature.

Weathering Tafoni at Salt Point, Sonoma Coast, California.

Rocks weather, sea beds get silted, salty water evaporates to provide clean water as rain, etc. are manifestations of a climate. A farmer plants seeds, squirrel collects nuts, or a bird builds a nest, all expecting a certain pattern of the climate. All living beings have an inherent capacity to adjust continuously to various levels of climatic conditions. And more often than not, organisms manage to survive even in unpredictable climates. When climatic changes are very sudden, different or very intense in time scale, complete annihilation of live form may occur. But most climatic effects set in over a long period, and new living forms are evolved through such adaptions.

House on River Kwai SE Asia

Climate manifests, with determinate and indeterminate aspects. With determinate aspects, we plan our actions and for indeterminate aspects, we discipline ourselves for unusual eventualities. Climate conditions our living. We, through our instincts and intuitions find ways not only to survive, but carry on all functions in a manner that is easier than ever before. Unlike other living beings, humans have the capacity to think and plan their actions, and, so achieve a greater degree of adaptability for climate.


Human beings generally become acclimatized to the normal climate of the area where they live and work. They also have some built in resilience for minor variations. Most societies adopt the climate, through physiological changes, material usage techniques, housing patterns, etc.


Built-form and climate, are inseparable issues. Through a continuous process of selection and elimination societies develop for themselves a lifestyle and this seems almost intuitive or natural for the particular environment. These lifestyles pass on from one generation to another, and consequently problems of climatic adaption do not occur, or are not so severe.


In stable societies few people move, and fewer house forms are transmitted from their original environment. Migrants usually try to transmit the original house form, to the place of their migration. Today large number of people migrate from one place to another. However young migrants, who have had no opportunity to imbibe the accumulated knowledge of climate adoption from the place of their origin, find it difficult to establish in an alien situation.


Builders, Architects or Interior Designers face the problems of climates at many different levels: These are:

1 Comfort,

2 Adaptability,

3 Setting a Life-style (food, clothes, time schedules, tasks handling, etc.),

4 Designing – creating – acquiring built-forms, architectonic elements – interior amenities.

Extreme hot-arid climate of Punjab India

Comfort: Over a period of time our needs and perceptions for comfort change. For example. People age, Social and Economic conditions change Preferences and means of life styles get recast. Technological innovations offer new options.

Adaptability: Problems of climatic adaptability are not acute, for static populations, but arise for migrants. Short term migrants are self motivated, or forced through political or calamity conditions. Long term shifting occurs due to shortage of local resources or major environmental changes. Adaptability of built-form also arises when mixed lot population (caste, religion, cultures) are allotted ‘standard design dwellings’. The new residents find that new house patterns and building materials are not conducive to continue their habitual climate-tested life styles. Similarly certain housing patterns, which were possible in old type of housing colonies, may not be physically or economically viable in the new housing setup.


Setting a Lifestyle (food, clothes, time schedules, tasks handling, etc.). Migrants have many acute problems that require immediate attention, and acquisition of a new life style to suit the changed built-form and its climatic responses are not of immediate priority. Migrants carry varied images of the built-form from places of their origin. The time-tested life style of their original living quarters was based on certain context like group, communal or neighbourhood living, which may not be available now.

Mae La refugee camp

Designing-creating-acquiring built-forms, architectonic elements-interior amenities. New or changed built-forms are required when there are major changes in the family profile, such as division of families divide, addition to families due to marriage, birth etc., death and migration of some members. The new members (parents, newly wedded couples etc.), either have very rigid concepts or may not have imbibed the traditional values that help a natural climatic adaption. Separating members have strong aspirations for a different life style (perceived from other sources), so disregard instinctive or natural climatic adaption processes. New members also have greater resources and better knowledge about how manage climatic related issues through modern devices.





Post 443 –by Gautam Shah



In an Interior Space, Comfort is ease of doing things, like handling tasks, sustaining life, relaxation, expression, communication, interaction, contemplation, and conducting many other affairs. The Interior space facilitates these with its built form, the environment, amenities and enrichments.

Factors defining the comfort conditions, whether,

  1. relating to absolute comfort,
  2. facilitation by the space, or
  3. related to the person are mutually dependent.

Card Players by Paul Cezanne

person_swimming_swim_lake_water-78918.jpg!dA ■ Some of the ABSOLUTE FORMATIVE ASPECTS for COMFORT are:

1. Climate (temperature, humidity, air movement and radiation) Read More here :- Interior Spaces and Climatic Comfort and Temperature Related Comfort Parameters for Interior Design

Comfortable dresses Women_of_Puducherry

2. Anthropometric, Ergonomics and Postures factors, Read More here :- Postures and Behaviour and Postures for Furniture Design -1 and Postures for Furniture Design -2 and Body Posture Systems and Body Postures 


3. Time management (Tasks, duration, cycles of task changes and social interactions) Read More here:- Tasks Shifting in Interior Spaces and Space Planning for Tasks and Interior Spaces as Settings for Tasks  


4. Metabolic activity (Quality of food, Basal Metabolic rate and physiological functionality) Read More here : –Temperature Management by Human Body 


BCOMFORT FACILITATION by the SPACE are closely related physiological accommodation and sensorial perceptions. Accommodation relates to space sizes, form and the perceptive scale which in turn allow physical posturing, social group formation, expression and interaction. A space is comforting due to the familiarity as much as it is invigorating due to the vibrancy and surprises. Space change occurs due to the environment and by its exposure from a different position.

Read more here Place in a Space And Space Sizes and Human Behaviour


CCOMFORT FACTORS RELATED to a PERSON at a very basic level are linked to the mechanisms of survival and level of adaptability. Many facets of comfort are universal for all humans, but it is also a personal matter of choice and aspiration. Personal matters cover, Life style, Clothing, Adornments, Social groupings and Time management. The comfort in interior space, subjectively and objectively, is a complex phenomenon, continuously varying with the needs, experience and age of the person.

Read more here Dealing with Environment And Postures and Designers




Post 433 — by Gautam Shah


Comfort of users in an interior environment depends on:

1. Temperature of Environment and our Body

2. Level of Humidity,

3. Air velocity,

4. Quality of Air.


TEMPERATURE OF ENVIRONMENT AND OUR BODY need to reach some equilibrium. In an Interior space, environmental temperature is modulated by the built form and its amenities. Direct solar radiation heats up various objects, depending on their thermal capacity, conductivity, colour, texture, etc. Heated objects radiate this heat, as long wave radiation, back into space after the main source has ceased its input. Delayed heat releases create very complex patterns of heat gain. A temperature profile in any space is rarely even and this causes different gradients and convective air movements. Such air movements affect the rate of evaporation and the level of humidity in a space, rate of ventilation, and quality of air.


All sides covered Winter beds

Temperature is the major determinant for comfort level. Air temperature determines the rate at which our body will exchange heat with the environment. Rate of heat exchange affects the metabolic activity of the body and as a result its work capacity, fatigue and recovery schedules. In a temperature range that is acutely different from the acclimatized one, our body has to work harder to adopt to the situation.

Street Sanaa Yemen

LEVEL OF HUMIDITY is the amount of vapour held by air at a particular temperature. With a rise in temperature, the expanded air accommodates more humidity, whereas a drop in temperature condenses the humidity. Proportion of humidity at any given temperature affects the rate of evaporation and the heat exchange of the body through perspiration. Excessive loss of humidity from body, and high proportion of humidity in air, both affect our sense of well being and comfort.

Hot-Humid climate Forest Rest House Theppakadu S India

In hot and humid climate high level of humidity does not allow adequate heat dissipation through evaporation of the perspiration. As a result body temperature increases and it has to resort to other methods of heat dissipation. In hot arid climates the low level of humidity causes rapid evaporation. Body cannot cope up with such rapid loss of moisture, as it has limited amounts of water available within it. In cold arid climates the body has no excessive amounts of heat requiring dissipation through high perspiration, however, the low level of humidity removes even the moisture that helps the skin to remain soft and supple. In cold humid climates even minute perspiration does not evaporate readily, and in excessively cold climates it may cause a frost bite.

Cracks and crevices offer passive ventilation

Air with high percentage of humidity is comparatively deficient in oxygen and may cause problems to people with TB or asthma. Low level of humidity removes the moisture from the nostril, reducing its filtering capacity to keep out the airborne pollutants.


AIR VELOCITY is caused by temperatures and pressures differences across locations, within connected spaces. Air can also become mobile due to fans or such air circulating devices. Air velocities go below 0.15 m/s, and most people complain of stuffiness, in spite of all other parameters of comfort being satisfactory. Air velocities above 1.5 m/s, are annoying, such as papers being blown out or dust stirred up. People may tolerate such extreme (high and low) air velocities under very hot-humid and cold-dry conditions or for the sake of body thermal management.

Children and aged persons have poor body Temperature control mechanism and so need to be protected

Draughts are low velocity air movements, which occur due to temperature and air pressure thresholds near cracks and such leakage points in enclosed spaces. In enclosed spaces, draughts are not always perceptible, as they do not cause any sensation of pressure on skin. Draughts, however, help in convective heat exchange, evaporation and dilution of pollutants in air. Draughts cause localized cooling or heating of sensitive organs of our body. Such sensation on feet is a common experience in trains, buses, sofas, undersides of office tables, etc. Children and aged people with deficient blood circulation and body temperature regulatory mechanisms, are readily affected by such currents.


Breeze is a low to medium velocity air movement, which affect only local areas. The breeze does not let air borne particulate matter to settle down. Breeze causes effective pressure on skin, with immediate and very perceptible skin sensation, which can be avoided by appropriate screening and deflection.

Thar Desert House with twigs -gaps crevices offer passive ventilation

Winds are very high velocity movements of air. Winds affect large regions, and few interior spaces. Winds raise particulate matter in the air, cause rapid change in level of humidity and cause discomfort due to high pressure sensation on the skin. In hot and cold both types of climates people often close all the openings to reduce the air movements and thereby control the convective heat gain or loss.

Trans Sahara Desert House Minimum openings

Turbulent air velocity is less comfortable than a laminar air velocity. Turbulent air movement achieves a better mix of air, whereas laminar helps in greater displacement of air mass. This is the reason why in hot arid climates small size opening is used to create turbulence or a viscous flow, and in hot humid climates body level openings help a laminar flow to displace the humidity.

Wind Catchers

QUALITY OF AIR represents the health supporting conditions of interior spaces. Pollution of internal air occurs due to occupation of space by people, plants and pets (exhalation, body odours, excretion product odours, food preparations), gadgets and equipment, building and furnishing materials. The quality of air is usually determined by people’s sensation to various odours present in the air. But certain harmful pollutants like carbon dioxide and radon cannot be perceived by people at high concentrations.


Quality of air is determined in two ways. There are absolute standards that provide for ideal conditions for comfort and bio survival. Relative standards provide ways for determining the qualitative difference between out door air and indoor air. Quality of outside air is generally superior because an infinite space and high speed winds are available for dilution to occur. Quality of internal air can be improved by diluting the proportion of pollutants in air, by replacing part of the fouled air with comparatively cleaner air, or by various mechanical and chemical scrubbers.

Particulate matter is a major source of air pollution, which mainly but not necessarily, originates outside and penetrates inside through various cracks and openings. Particulate can be dust, fumes, mist or biogenic matter. Particles of diameters greater than about 75 microns settle out rapidly and are termed grit. Particles of smaller than 50 microns may remain suspended and constitute aerosols. An aerosol is a liquid or solid particle which is in a quasi stable suspension in air. Very fine aerosols may remain suspended for weeks, whereas larger aerosols may get deposited in minutes. The deposition of very small particles (2 microns) is influenced by temperature gradient (through convective currents). The effect on health due to airborne particulate matter of biogenic origin such as fungi, moulds, bacteria, viruses, pollen are well known.

Kitchen major zone for Air contamination

In modern artificially controlled environment buildings are well designed and sealed to eliminate waste leakages. Such spaces function well so far as environmental systems operate. Pollutants arising from building materials, aerosols settling down, degradation of biotic materials, evaporation of condensed moisture from air handling plants, etc. continue to be added to the internal environment but at night time, on off days and when there are power breakdowns, there is no casual ventilation.



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.


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 %).