PIR vs PU vs Phenolic: Which Pre-insulated Duct Is Right for You?

When it comes to modern HVAC ductwork, pre-insulated duct panels are quickly becoming the industry standard — thanks to their outstanding energy efficiency, lightweight structure, and simplified installation. However, choosing the right core insulation material is crucial for ensuring long-term performance and project success. In this article, we compare the three most common types of pre-insulated duct materials: PIR (Polyisocyanurate), PU (Polyurethane), and Phenolic foam.

1. PIR Pre-insulated Duct Panels

Polyisocyanurate (PIR) foam is an advanced version of polyurethane with improved fire performance and thermal resistance. It is widely adopted in commercial HVAC systems due to its balanced performance across multiple factors.

Key Benefits:

Low thermal conductivity (as low as 0.022 W/m·K)
Excellent flame retardancy and low smoke emission
Lightweight and rigid structure
Long-term thermal stability

Recommended for:

High-performance HVAC systems in commercial buildings
Projects with strict fire safety requirements
Applications requiring long duct runs with minimal energy loss

Pre-insulated PID Duct Panel in Vietnam and Thailand Singapore

2. PU Pre-insulated Duct Panels

Polyurethan (PU) is a reliable and cost-effective foam insulation material. While slightly less fire-resistant than PIR, PU still offers excellent insulation properties and is ideal for projects prioritizing budget efficiency.

Key Benefits:

Efficient insulation with λ values typically around 0.018–0.025 W/m·K
Lightweight and easy to install
Cost-effective for large-scale applications

Recommended for:

Residential HVAC systems
Budget-sensitive commercial projects
Systems without stringent fire code restrictions

PID PIR duct board PAL duct

3. Phenolic Pre-insulated Duct Panels

Phenolic foam is known for its superior fire performance and extremely low smoke emissions, making it ideal for critical environments. It also has the lowest thermal conductivity among the three.

Key Benefits:

Exceptional fire resistance (often Class 0 or Class A)
Very low smoke generation
Outstanding thermal performance (as low as 0.020 W/m·K)
High compressive strength

Recommended for:

Hospitals, airports, and cleanrooms
Government or institutional projects with strict safety codes
Projects seeking long-term energy efficiency and compliance
Comparison at a Glance

GFI phenolic foam insulation

Comparison at a Glance

Feature	PIR-Schaum	PU Foam	Phenolic Foam
Thermal Conductivity (W/m·K)	~0.021	~0.023	~0.018
Fire Performance	Good	Moderate	Excellent
Smoke Emission	Low	Moderate	Very Low
Weight	Lightweight	Lightweight	Lightweight
Cost	Moderate	Lower	Higher
Application Scope	Commercial HVAC	Residential & Light Commercial	Critical Facilities

Which One Should You Choose?

The right material depends on your project priorities:
Need high fire safety + long-term efficiency? Choose Phenolic.
Looking for solid all-around performance? Go with PIR.
Tight budget with basic requirements? PU might be your best bet.

At GFIDuct, we manufacture and supply high-quality pre-insulated duct panels using PIR, PU, and Phenolic foam, tailored for HVAC contractors, distributors, and engineering firms worldwide. Whether you’re working on a high-rise commercial tower or a compact indoor project, we have the right duct solution for you.