Passive control methods of Kerala traditional architecture for a comfortable indoor environment: A comparative investigation during winter and summer

Kerala is a strip of land on the southwest coast of India lying between Arabian Sea on the west and Western Ghats on the east. The traditional architecture of Kerala is known for its use of natural and passive methods for a comfortable indoor environment. However, it has not been proved by a detailed and quantitative evaluation method so far. A field study was thus conducted in the winter and summer periods to investigate the indoor environmental condition of a typical Kerala traditional residential building. The objective of the investigation was to understand the passive environment control system of Kerala traditional architecture by quantitative analysis of various thermal comfort parameters. It was done by continuously monitoring the indoor and outdoor conditions using a custom made instrument called “Architectural Evaluation System”. The results show that the natural and passive control system of Kerala traditional architecture provides comfortable indoor environment irrespective of the outdoor climatic conditions.     

Response of high yielding coconut variety and hybrids to fertilization under rainfed and irrigated conditions

A long-term experiment was conducted to study the differential fertilizer response of high yielding West Coast Tall variety, Chowghat Orange Dwarf (COD) × West Coast Tall (WCT) and WCT × COD hybrids of coconut for growth, nutrition, yield and economic returns under rainfed and irrigated conditions at Central Plantation Crops Research Institute, Kasaragod. The average yield for 8 years showed that the fertilizer treatment 1000 g N: 437g P: 1667g K palm^–1 yr^–1 (M₂) recorded significantly higher nut yield (136 nuts palm^–1 yr^–1) than M₁ treatment (500 g N: 218 g P: 833 g K palm^–1 yr^–1) and no fertilizer application (M₀). Amongst the variety/hybrids, the hybrid COD × WCT (128 nuts palm^–1 yr^–1) out yielded its reciprocal cross (114 nuts palm^–1 yr^–1) and WCT variety (115 nuts palm^–1 yr^–1). The growth parameters recorded did not show any significant difference in tree height and girth at base among the variety/hybrids. However, fertilizer application significantly increased the trunk height and girth at base. Annual application of fertilizers for a period of 32 years to coconut resulted in a marked increase in available phosphorus and potassium status in soil, but a marginal change in soil available nitrogen status was observed. Foliar contents of N remained below the critical levels of 1.8–2.0%. Phosphorus buildup in the soil due to fertilizers, did not reflect in the P contents of diagnostic leaf under both rainfed and irrigated conditions. Application of K fertilizer at M₁ level maintained K content of leaves at 1.07% i.e. just above the critical level (0.8–1.0%), whereas application of K fertilizers at M₂ level raised the leaf K content to 1.20%. The leaf nutrient contents did not vary much among variety/hybrids due to fertilizer application. The cost-benefit ratio was most favourable under fertilizer treatment M₁. For every rupee (Rs) invested on manuring, the total net return was Rs 2.80 under M₁ level and Rs 2.85 under M₂ level of fertilizers.     

Passive control methods of Kerala traditional architecture for a comfortable indoor environment: Comparative investigation during various periods of rainy season

The traditional architecture of Kerala, a state in India lying along its southwest coast, is known for its use of natural and passive methods for a comfortable indoor environment. Although there have been attempts to analyze the traditional architecture of Kerala, they were focused only on qualitative approach. An investigation was thus initiated by the authors to understand the passive environment control system of Kerala traditional architecture in providing better thermal comfort, by continuously monitoring thermal comfort parameters of a typical traditional residential building over a period of time. The inferences of the first phase of the investigation carried out during winter and summer seasons, lasting about half of the year have already been published. This paper illustrates the inferences of the second phase of the investigation that is carried out during the rainy season of the year. A comparative analysis with the results of the winter and summer periods is also incorporated. The investigation has revealed that, when the outside ambient temperature is below normal, the building system tries to maintain the indoor air temperature at a higher but comfortable level and when the outside temperature is above normal, the indoor is kept at a lower but comfortable level. It is found that a continuous gentle wind flow is maintained inside the building irrespective of the wind outside. The required level of thermal comfort is achieved by maintaining a balanced level of temperature and relative humidity along with a continuous and controlled airflow inside the building irrespective of seasons.     

RETHINKING INDIAN MODERNITY FROM THE MARGINS: ARCHITECTURAL POLITICS IN THIRUVANANTHAPURAM IN THE 1970s

This paper interprets the context and implications of a little-known but consequential ideological feud that emerged between rival “regionalist” and “modernist” camps of architectural practitioners in the south Indian state of Kerala in the 1970s. Beginning with a comparative analysis of the private residences of the key protagonists—the expatriate British Gandhian, Laurie Baker, and J. C. Alexander, an influential modernist and doyen of the architectural profession in post-independence Kerala—the paper explores the contrasting views of both camps as they debated the idea of the modern house. Turning to the architectural historiography of modern India, the over-representation of one camp and the relative invisibility of the other is then examined in the context of the radical cultural and political climate of the 1970s in Kerala. The paper considers how Baker’s rise to wider recognition and impact by the end of the 1970s can be understood only by understanding the “author function” that Baker satisfied in Kerala society. The paper concludes that the complex network of influences and actors that appear in this specific case study, drawn from the assumed margins of India’s modern architectural history, makes the case for a flatter ontology of history, rejecting the existing “diffusion” model and enabling buildings and context to speak in equal measure.     

Passive environment control system of Kerala vernacular residential architecture for a comfortable indoor environment: A qualitative and quantitative analyses

The modern day practice does not give due respect to passive and natural environment control measures in buildings. With modern materials and technology, the buildings of present architectural style results in high energy consumption, in an attempt to provide thermal comfort indoors. The vernacular architecture at any place on the other hand has evolved through ages by consistent and continuous effort for more efficient and perfect solutions. The authors have conducted a qualitative analysis of the passive environment control system of vernacular residential architecture of Kerala that is known for ages for its use of natural and passive methods for a comfortable indoor environment. The orientation of building, internal arrangement of spaces, the presence of internal courtyard, use of locally available materials and special methods of construction, etc. have together created the indoor environment. A quantitative analysis was also carried out based on field experiments by recording thermal comfort parameters in a selected building. The study has provided positive results confirming that the passive environment control system employed in Kerala vernacular architecture is highly effective in providing thermal comfort indoors in all seasons.     

Effect of NPK fertilization on the mineral nutrition and yield of three coconut genotypes

Annual application of NPK fertilizers over a 18 year period to coconut on red sandy loam soils resulted in a minimal increase in mineralisable N, but in a marked increase in available P and K. Plant N levels, however, reflected the improved N nutrition but did not reach sufficiency levels found elsewhere. An available P status of 15 ppm in the control plots kept leaf P at sufficiency levels. P fertilizers did not increase the P content of leaves. K fertilizers raised the K leaf content to sufficiency levels. Doubling the M₁ fertilizer rates of 500 g N, 220 g P and 830 g K per palm per year had no effect on N, P and K levels in the palm leaves.Changes in K levels of the leaves had antagonistic effects on leaf Mg (r = – 0.68^**) and leaf Na (r = – 0.87^**). As this effect brings leaf Mg close to deficiency values palms receiving K might need additional Mg as well.The findings and interpretation of soil and leaf analysis data were confirmed by large yield responses to application of NPK fertilizers. Genetic differences between palms in their response to levels of nutrient supplies were apparent. The CDO × WCT hybrid outyielded the high yielding WCT variety especially when NPK was given at the M₁ level. The response in yield to applied fertilizers was linear for WCT and curvilinear for the hybrids CDO × WCT and WCT × CDO.     

Determining the spatial variation of phosphorus in a lake system using remote sensing techniques

Lakes are versatile ecosystems, with eutrophication being a serious problem affecting their condition and trophic status. Eutrophication can lead to an over‐abundance of macrophytes in lakes, producing favourable conditions for mosquito larvae. Increased eutrophication is attributed in most to excessive phosphorus concentrations in lake water. Satellite imagery analysis now plays a prominent role for quickly assessing water quality over a large area. The present study is an attempt to illustrate the variation of phosphate and total phosphorus concentrations in Akkulam–Veli Lake, Kerala, India, using Indian Remote Sensing satellite (IRS P6‐ LISS III) imagery. A multiple regression equation derived using radiance in the red and MIR bands in the imagery was found to yield superior results for predicting the phosphate concentration, whereas a simple regression equation using radiance in red band was found to yield good results for the total phosphorus concentration in lake water. Accordingly, the trophic status of the lake system can be determined easily from satellite imagery in this manner.