In any urban place of India, if we look around, a plethora of window air conditioner boxes appears in the view. Yes, there cannot be a second thought that – with the growing global temperature, need for residential air conditioning is increasing. However, considering the rising energy price, maintaining room air conditioners is gradually becoming more and more burdensome for the middle-class people in the society.
But there are a few ways to keep a building moderately cool without much consumption of electrical energy, which are often overlooked during construction of a building. Integrating passive design elements with mechanical systems is a holistic approach to building cooling that is most effective when implemented early in the design phase. These strategies, many of which are inspired by traditional architecture, work to reduce heat gain and dissipate heat naturally, minimising the reliance on energy-intensive air conditioning.
A building’s position and orientation are foundational to controlling solar heat gain. Orienting a building along an east-west axis minimises exposure of the largest facades to the low-angle sun in the morning and afternoon.
Also, strategically planted deciduous trees and other vegetation can shade a building from the high summer sun while allowing natural light and warmth to pass through in the winter. Plants also create cooler outdoor air through evapotranspiration.
The right amount and type of insulation is a critical barrier to heat flow through walls, roofs, and floors. Optimal insulation reduces heat gain in the summer, lowers cooling loads, and improves thermal comfort.
We have to remember that windows and skylights constitute a major source of heat gain. Using high-performance, double- or triple-glazed windows with low Solar Heat Gain Coefficients (SHGC) can dramatically reduce heat transmission. For east- and west-facing windows, external shading is even more effective than insulated glass.
Installing a radiant barrier in the attic can reflect solar heat radiation before it enters the conditioned space. Using light-coloured or highly reflective paint and roofing materials on exterior surfaces also reduces heat absorption.
Thus, ways are there but that needs little care.
Pravita Iyer
Publisher & Director
