PU vs PIR panels: insulation value, fire performance and cost

PU and PIR are both polyurethane-based insulation cores and look almost identical. The difference lies in the chemistry of the core, and it shows up clearly in fire performance, thermal stability and price.

Comparison at a glance

1. Insulation value

PIR’s thermal conductivity is about 10% lower than PU’s. Across a large cold store envelope that difference accumulates into a meaningful electricity saving over the operating life — enough to cover the higher material cost up front.

2. Fire performance

This is the biggest difference. PIR’s isocyanurate ring structure is more thermally stable and chars when exposed to flame, forming a protective layer that limits spread and reduces smoke. PU is moderate, and suits projects without strict fire requirements.

3. Thermal stability

PU works reliably from -40°C to +80°C; PIR extends that to +120°C. On a factory roof in full sun in central or southern Vietnam, surface temperatures swing high enough that PIR is the safer long-term choice.

4. Cost

PIR costs more than PU. But the sum should be done over the whole life: running electricity, insurance, and the risk of having to replace the panels if the building’s fire requirements are later upgraded.

Which should you choose?

• Choose PU for ordinary production factories, offices and civil buildings where budget is the priority.
• Choose PIR for cold stores, cleanrooms, food and pharmaceutical plants, or any project that has to pass fire approval.

No panel is best for every project — only the one that best fits that project’s technical requirements and budget.

– Phu Son Group