A PMV-PPD model based study of thermal comfort in Low-Income Group house in Chhattisgarh

People tend to maintain symmetry between comfort and economy while choosing essential commodities needed in their life. Families buy a house which may offer comfort condition, but at minimum in term expenses of energy throughout a life. Thus, it is most important to erect a house to provide comfortable condition and moderate the lifetime expenditure by saving energy consumption. Sensation of thermal comfort varies from people to people, even in an identical environment. To minimize the consumption of energy of building, cost of consumed energy and to provide a comfortable house, thermal comfort analysis in indoor environments have attracted many researchers. Fanger’s Predicted Mean Vote (PMV) - Predicted Percentage of Dissatisfied (PPD) model is widely accepted theory for assessment of building indoor thermal conditions. In the present work, thermal comfort of an LIG house in Chhattisgarh region of India has been analyzed based on PMV-PPD method for months representing three different seasons in a year i.e. May, September and December representing summer, post monsoon and winter respectively. Cooling, heating and actual energy load of LIG house has been calculated and reported for the above mentioned months. From analysis it is concluded that inhabitants are comfortable only during the winter.

Predicting the hydraulic and life-cycle cost performance of rainwater harvesting systems using a computer based modelling tool

Rainwater harvesting systems are a recognised technique for reducing reliance on potable mains supply and as a potential way to save money. However, the widespread uptake of these systems has been slow partly due to the level of uncertainty surrounding hydraulic and financial performance. Current methods of assessment tend to be simplistic, using generalised rather than site-specific data. Often little account is taken of financial issues other than capital costs, such as operating/maintenance and decommissioning expenses. To overcome these shortcomings, a computer based modelling tool called RainCycle© was developed that has the capability to perform more detailed analysis than is possible with existing methods. The program includes a detailed hydraulic model of a typical rainwater harvesting system and also has the ability to explicitly account for all major costs associated with these systems. Modelling a number of proposed designs revealed that many of the current methods overestimate the hydraulic efficiency and potential cost savings that are achievable. However, it was found that water and monetary savings are still possible under favourable conditions. Further, it was found that capital, maintenance and required mains top-up water account for the majority of the whole life costs, whilst energy and decommissioning costs represent a small fraction of the required lifetime expenditure.