If you’re planning to build a cold room, one of the first decisions you’ll make is choosing the right insulation panel.
The two most common options are PUR (polyurethane) and PIR (polyisocyanurate) insulation panels. While both look similar, they perform differently in areas such as thermal insulation, fire performance, cost, and long-term durability.
So, which one is right for your project? In this guide, we’ll compare PUR vs PIR insulation panels side by side and explain when each option makes the most sense for cold rooms, freezer rooms, and refrigerated warehouses.
PUR vs PIR: Quick Comparison
If you’re looking for a quick answer, here’s the difference.
- PUR panels are cost-effective solution for standard cold rooms and chilled storage
- PIR panels offer better fire performance and thermal stability, which makes them a better choice for freezer rooms and projects with stricter safety requirements.
The right choice always depends on your operating temperature, budget, and project requirements.
| PUR vs PIR Comparison Table | ||
| Property | PUR Sandwich Panels | PIR Sandwich Panels |
| Thermal Conductivity | 0.022-0.026 W/m·K | 0.021-0.023 W/m·K |
| R-value | R-6.0 to R-6.8 | R-6.5 to R-7.2 |
| Density | 40–42 kg/m³ | 40–42 kg/m³ |
| Closed-Cell Content | 90%+ | 90-95%+ |
| Compressive Strength | 150–200 kPa | 150–200 kPa |
| Water Absorption | ~2.5-3% | ~0.9% |
| Fire Behavior | Good | Better |
| Maximum Service Temperature | 80°C | 120°C |
| Relative Material Cost | Baseline | Often 5-15% higher |
| note: actual values vary by manufacturer, panel density, facing material, and test method. | ||
What are PUR Insulation Panels?
PUR insulation panels use a rigid polyurethane foam core sandwiched between two metal sheets.
They are one of the most widely used insulation panels in commercial refrigeration because they provide reliable thermal insulation at an affordable price.
PUR panels are commonly used for:
- Walk-in chillers
- Food storage rooms
- Beverage coolers
- Fresh produce storage
- Small and medium-sized cold rooms
What are PIR Insulation Panels?
PIR insulation panels are also sandwich panels, but they use a polyisocyanurate foam core.
Compared to PUR, PIR has a modified chemical structure that improves its thermal stability and fire performance.
PIR panels are commonly selected for:
- Freezer rooms
- Pharmaceutical cold storage
- Food processing facilities
- Frozen warehouses
- Industrial cold storage projects
PUR vs PIR Thermal Performance
Thermal performance shows how well a panel slows heat transfer. Better insulation means the refrigeration system works less to maintain the target temperature.
Two common measurements are:
- Thermal conductivity: Lower is better
- R-value: Higher is better
PUR panels usually have a thermal conductivity of around 0.022-0.026 W/m·K and an R-value of about R-6.0 to R-6.8 per inch.
PIR panels, on the other hand, have a thermal conductivity of around 0.021-0.023 W/m·K and a higher R-value of about R-6.5 to R-7.2 per inch.
This means PIR can reduce heat transfer slightly better at the same thickness. For standard cold rooms, PUR is often enough. For freezer rooms or lower-temperature storage, PIR may offer better long-term energy performance.
PUR vs PIR Fire Performance
Fire performance is one of the main differences between PUR and PIR insulation panels.
PIR panels usually perform better than PUR panels when exposed to high temperatures. A recent study found that PIR foam had about 50% lower peak heat release than PUR foam. It also had a much higher char yield, at over 22 wt.% compared to about 3wt.% for PUR.
This matters because char acts like a protective layer. It helps slow heat release and improves the panel’s fire behavior.
However , PIR should not be described as fireproof unless the specific panel has a certified classification that supports that claim. Actual fire performance depends on the tested panel assembly, including the foam core, steel facings, joint design, sealant fixings, installation quality, and the relevant fire test standard or certification.
PUR vs PIR Moisture Resistance
Both PUR and PIR insulation panels use closed-cell foam, giving them strong resistance to moisture. But, PIR panels absorb less water than PUR panels. Based on our panel data, PUR panels have a water absorption rate around 2.5% to 3%, while PIR panels are around 0.9%,
This lower water absorption helps PIR panels maintain insulation performance in cold rooms, freezer rooms, and other humid refrigeration environments.
Still moisture resistance also depends on proper sealing, protected metal facing, and correct installation.
The bottom line is both PUR and PIR resist moisture well, but PIR has a clear advantage with lower water absorption compared with PUR.
PUR vs PIR Panel Thickness
Cold room panel thickness affects both insulation performance and project cost. Thicker panels reduce heat transfer, but they also cost more. The right thickness should match the room temperature and application.
| Application | Temperature | Common Thickness |
| Chiller Room | 0°C to +10°C | 75 – 100mm |
| Freezer Room | -18°C to -25°C | 120 – 150mm |
| Frozen Warehouse | Below -18° | 150 – 180mm |
| Blast Freezer | Below -30°C | 150 – 200mm+ |
| Pharma Cold Room | 2°C to +8°C | 75 – 100mm |
PIR panels may provide similar insulation with slightly less thickness because of their higher R-value.
PUR vs PIR Cost Comparison
Cost is one of the biggest deciding factors when comparing PUR vs PIR insulation panels.
In general, PUR panels have a lower upfront cost, which makes them a popular choice for standard cold rooms and budget-conscious projects.
PIR panels typically cost more because of their improved fire performance and higher thermal stability. But, the final price depends on factors such as panel thickness, steel facing, coating, density, fire rating, and order quantity.
When comparing costs, it’s important to look beyond the purchase price. For freezer rooms and other demanding applications, PIR’s better insulation performance and fire behavior may provide long-term value through lower operating costs and improved safety.
PUR vs PIR Durability and Long-Term Performance
Both PUR and PIR panels can last 20-30+ years when installed, sealed and maintained correctly.
In terms of strength, they are often similar. Both commonly have a compressive strength of around 150-250 kPa, depending on foam density and panel design.
The main difference is thermal stability. PUR performs well in standard cold room conditions, while PIR can handle higher service temperatures, often around 120°C compared with about 80°C for PUR. This gives PIR an advantage in demanding projects where long term stability is important.
Common Mistakes When Comparing PUR and PIR Panels
When comparing PUR vs PIR insulation panels, do not choose based on price alone.
Common mistakes include:
- Choosing the cheapest panel
- Checking only the R-value
- Ignoring thermal conductivity
- Using the wrong panel thickness
- Skipping fire test reports
- Overlooking sealing and installation quality
- Buying without technical support
R-value is important, but it is only one part of the equation. Poor sealing or wrong installation can reduce the performance of any panel.
Buyer Checklist
Before ordering PUR or PIR cold room panels, ask your supplier for:
- Thermal conductivity W/m.k
- R-value per inch or per panel thickness
- Panel thickness in mm
- Foam density in kg/m3
- Compressive strength in kPa
- Closed-cell content
- Water absorption value
- Fire classification
- Full panel test report
- Steel sheet thickness
- Surface coating types
- Joint design
- Installation guide
- Warranty terms
- Recommended temperature range
A reliable supplier should provide a clear technical data, not only a marketing claim.
Final thought
Both PUR and PIR insulation panels can work well for cold rooms, but the right choice depends on your needs.
Choose PUR for lower upfront cost and standard cold room applications. Choose PIR when fire performance, thermal stability, and long-term value matter more.
At Sunnyda Cold Room, we help customers choose the right PUR or PIR panels based on temperature, budget, and project requirements, so their cold rooms perform reliably for years.
You may also find these blog posts useful:
Sandwich Panels: Types, Advantages, and Applications – The Ultimate Guide
Polystyrene vs Polyurethane: Understanding their Differences
