Question

The best raw material for construction of cold storage is

• A. Steel
• B. Cement concrete
• C. Polyurethane foam panels
• D. Iron

Hint:

Cold Storage Insulation Materials: Best Modern Material = POLYURETHANE FOAM (PUF) Panels (Lowest thermal conductivity $k = 0.022\text{ W/m}\cdot\text{K}$). Traditional = Expanded Cork.

Answer 1

The Correct Option is C

Step 1: Understanding the Concept:
Refrigeration engineering and thermal insulation: Polyurethane Foam (PUF) sandwich panels provide the lowest thermal conductivity ($k pprox 0.022 ext{ W/m}\cdot ext{K}$) and superior closed-cell vapor barrier insulation for modern cold storage construction.
Key Formula or Approach:
\[ k_{\text{PUF}} \approx 0.020 - 0.024\text{ W/m}\cdot\text{K} \quad \ll \quad k_{\text{Cork}} (0.040) \ll k_{\text{Concrete}} (1.4\text{ W/m}\cdot\text{K}) \]

Step 2: Detailed Explanation:
In refrigeration engineering and commercial cold store construction:
- Polyurethane Foam (PUF) Insulated Sandwich Panels (C) represent the best, most energy-efficient modern raw material for building cold storage, blast freezers, and refrigerated fish holds because:
1. Lowest Thermal Conductivity ($k$): $0.022\text{ W/m}\cdot\text{K}$, providing maximum thermal insulation with minimal wall thickness.
2. Closed-Cell Structure ($> 95\%$): Completely prevents moisture vapor condensation and water absorption inside insulation walls.
3. Lightweight, structural rigidity, modular pre-fabricated interlocking construction, and fire-retardant properties.

Step 3: Final Answer:
Hence, the best raw material is Polyurethane foam panels, matching option (C).