Cold insulation must control heat ingress, prevent surface condensation and frost, manage moisture, and withstand mechanical loads while meeting required fire performance and long‑term durability.
On cold surfaces, continuous vapor control is essential to prevent condensation, corrosion under insulation, and freeze damage; closed‑cell elastomeric foams and other closed‑cell materials are commonly specified because they limit moisture ingress and reduce surface emissivity.
Rigid boards and composite panels are preferred for flat surfaces and large panels where dimensional stability and compressive strength are required.
Flexible tubes, sheets, and pre‑formed sections are appropriate for piping, ducts, and irregular geometry because they conform easily and simplify field installation.
Effective cold‑insulation systems combine low thermal conductivity, robust vapor control, mechanical protection, and appropriate fire performance to meet operational and safety requirements.
| Material | Max service temp | Thermal conductivity | Typical form | Key advantage |
| Polyurethane foam | ~80–100 °C (short term) | ~0.022–0.028 W/m·K | Rigid boards, spray, PIR-faced panels | Highest R‑value per thickness |
| Polyisocyanurate (PIR) foam | ~100–130 °C (short term) | ~0.021–0.026 W/m·K | Rigid boards, sandwich panels | High R‑value with improved fire performance vs PUR |
| Cross‑linked polyolefin (XLPE) closed‑cell | ~100–150 °C depending on grade | ~0.032–0.040 W/m·K | Flexible tubes, sheets, rolls | Flexible, closed‑cell vapor control for pipes/ducts |
| Expanded polystyrene (EPS) | ~70–90 °C (short term) | ~0.032–0.040 W/m·K | Rigid boards, blocks | Low cost and easy to shape; vapor‑permeable |
| Extruded polystyrene (XPS) | ~75–100 °C (short term) | ~0.029–0.036 W/m·K | Rigid boards, tapered boards | Higher compressive strength and water resistance vs EPS |
| Phenolic foam | ~100–130 °C (short term) | ~0.019–0.025 W/m·K | Rigid boards, panels | Very low thermal conductivity and good fire/smoke performance |
| Elastomeric rubber | ~100–220 °C depending on formulation | ~0.034–0.040 W/m·K | Flexible tubes, sheets, rolls | Excellent condensation control and easy field installation |
| Cellular glass (Foamglas) | ~400–800 °C (inorganic glass matrix) | ~0.038–0.050 W/m·K | Rigid blocks, pipe sections, slabs | Zero water absorption, high compressive strength, long life |
Key design considerations
