Harnessing Energy Efficiency- The Impact Of Solar Control And Double-Glazed Glass In Modern Building Design
The 2024 edition of the Glass Academy Webinar series featured Ar. Faiza Khan, Founding Partner at Field Architects, Ladakh. An architect and innovator with a decade’s experience in practicing architecture in the cold climate, Ar. Faiza, along with Ms. Kaarnika of Saint-Gobain, imparted valuable knowledge about harnessing energy efficiency in today’s construction world, especially in eco-sensitive areas.
As co-creator of a design practice rooted in the vernacular of the trans-Himalayas, Ar. Faiza’s talk centred around their innovative interventions in sustainable and green building design – wherein key considerations need to ensure maximum thermal comfort.
Project Name- ThinLars Residence
Source- Field architects
For example, in terms of materiality, in areas where cement walls do not perform, earthen facades in combination with solar control glass, prove to be better design solutions – providing better thermal insulation. She elaborated that to optimise solar heat gains, special facade systems are to be employed on the ‘solar south’, the most important of all 4 facades. She pinpointed one of her most tried and tested interventions, the Trombe wall system: a 20cm cavity flanked by an insulated glazing unit wall on the outer side and a thermal mass wall on the inner. Here, radiation is captured using both convection and conduction heating, invoking near-perfect thermal insulation.
Interspersed with insights from Ar. Faiza was Ms. Kaarnika’s technical detail support, delving into specifics of what constitutes good quality glass and what parameters are to be considered:
- Visual Light Transmission (VLT): The percentage of visible light that passes through the glass.
- Solar Heat Gain Coefficient (SHGC): The measure of direct solar heat gain due to radiation.
- U-Value (Thermal Transmittance): The amount of heat transferred through the glass due to temperature differences.
She also unpacks IGUs or insulated glazing units: essentially a small-scaled trombe wall. A vacuum or inert gas-filled gap flanked by two glass units with an advanced coating that can control solar heat gain and allow abundant natural light transmission. Its benefits are adaptable to both cold and hot climates, where different parameters come into play – In cold harsh climates like Ladakh, the U-Value of these glass units traps the heat within the living spaces.
At this juncture, Ar. Faiza’s extensive expertise in building in endangered terrains came into play, and she stressed the importance of sourcing materials locally and furnishing replacements for insulated glass units in case they are not available readily: toughened or laminated sandwich glass for energy-efficient windows.
With this, she dived into a project by Field Architects, The ThinLars Home, for a family of 3, in the Saboo Thang area near Leh. Among the many passive solar heating techniques, like rammed earth walls, straw-clay slab underlayers, and repurposed-mattress insulated adobe walls, the architects set a spotlight on the southern glass facade system: the Trombe wall in combination with a greenhouse.
Project Name- ThinLars Residence
Source- Field architects
The design of this home excels in terms of planning, since the spaces inhabited by night, like bedrooms, are majorly enclosed by the Trombe wall, to allow retaining of heat gained in the day for use at night. For spaces used in the day, like the living room and kitchen, the greenhouse assists through humidity-related heat retention, the perfect counter-measure in climatic conditions that are cold and dry.
Project Name- ThinLars Residence
Source- Field architects
Ar. Faiza emphasises how employing passive solar design brings about +12-15 degrees of heat gain even in negative temperature zones, helping them thwart even fueled heating systems.
With this webinar session, the most important ethos of sustainable architecture shines bright: that thoughtful design can enhance the daily lives of users. Ar. Faiza and the story of Field Architects, and the experiences she shared with us in terms of cost considerations, design compromises, regulatory byelaws and hurdles, maintenance and durability of materials, all from the viewpoints of renewable systems will remain a very important lesson in our repertoire of knowledge.
Interview by Shruthi Miranalini