Laminated glazing for buildings: energy saving, natural daylighting, and CO₂ emission mitigation prospective

Operational energy use and energy-based GHG emissions of air-conditioning in the building sector are increasing aggressively due to occupants' higher thermal and visual comfort aspirations. Window glazing is the critical building component that affects the thermal performance of the conditioned space. The existing glazing in the buildings allows huge heat gain/loss, leading to additional energy requirements for HVAC systems. Novel laminated glasses with various solar control film interlayers were studied in this article to improve the thermal performance of the conditioned space. Solar-optical properties and thermal indices of proposed laminated glasses were explored to study the potential energy savings and carbon emission mitigations. Thermal loads and energy savings were calculated with the help of a validated mathematical model across three distinct Indian climates (hot, cold, and composite). Substantial reductions in heat gain/loss and energy requirements were found with laminated glasses compared to monolithic clear glass. The laminated glass with reflective solar control film glazing (LG_RF) had concluded a cost saving of 100.84 $/year with a payback period of 1.7 years for cold climate in S-E orientation. CO₂ emission mitigation of building with laminated glasses was calculated for the energies conserved with carbon emission factors. The LG_RF had reported a carbon emission mitigation of 2.1 tCO₂/year for cold climates and comparable results for hot and composite climates. Daylight performance was carried out with the DesignBuilder simulation tool to assess the daylight accession in building interiors with laminated glasses. The laminated glasses were able to reduce annual energy requirements without greatly affecting the daylight inflow.