PSI - Issue 70

Dharshan V et al. / Procedia Structural Integrity 70 (2025) 493–500

498

U = 1

(1)

R total

Where,

U = Thermal transmittance (W/m²·K) R total = Total thermal resistance of the element (m²·K/W) R = d/k for each material layer d = thickness (m) k = thermal conductivity (W/m·K)

Table 4. Properties of external wall Material

Thickness (m)

k (W/m·K)

R-value (m²·K/W)

Plaster (Gypsum)

0.015 0.045

0.51

0.0294

Rigid Insulation (Polystyrene)

0.025

1.8

Brick (Common) Fiberglass Batt Plaster (Gypsum)

0.2

0.54

0.3704 2.3684 0.0294

0.045 0.015

0.019

0.51

Table 5. Properties of external wall Material

Thickness (m)

k (W/m·K)

R-value (m²·K/W)

Tile

0.02

0.057

0.3509 0.0239

Concrete

0.025 0.065

1.0459

Rigid Insulation (Polystyrene)

0.025 1.046

2.6

Cast-in-Place Concrete

0.1

0.0956

3.4.2.2 Glazing and Surface Reflection The building’s glazing was chosen to balance daylight, solar heat control, and insulation. With a Visible Light Transmittance (VLT) of 0.45, it allows sufficient natural light inside, while an SHGC of 0.27 limits solar heat gain, reducing cooling needs. A U- value of 1.9873 W/m²·K ensures good thermal insulation. The use of 1/4 inch low -E double glazing further enhances performance by reducing heat transfer. This setup supports visual comfort, energy savings, and complies with ECBC 2017 standards. Interior surface reflectance values also followed ECBC 2017 to optimize both daylight and artificial lighting. Reflectance was set at 50% for walls, 20% for floors, and 70% for ceilings, improving light distribution and visual comfort. In daylight zones, bright ceilings enhanced lighting efficiency, while controlled wall and floor reflectance reduced glare. The Light Reflectance Value (LRV) method guided material choices, including light- colored matte paints for walls (~50%), white ceilings (≥70%), and dark, matte floor finishes (~20%) — all contributing to sustainability and energy efficiency. 3.4.3 Building energy performance and solar analysis Examining the energy use of a facility is a critical factor for achieving long-term sustainability. In the case of the hospital, Autodesk Revit and Insight were used to create an energy model based on local climate data and design parameters. The simulation assessed several factors, including wall and window types, glazing performance, building orientation, and HVAC system efficiency. After completing the full 3D model in Revit, the building information was exported to Autodesk Insight, where the Energy Use Intensity (EUI) was calculated. The resulting EUI was 343.05 kWh/m²/year — acceptable for a facility operating 24/7 and housing high-demand units like ICUs, sterile services, and imaging equipment.

Fig. 5. Solar analysis result