Damvent

The performance of air-handling systems (AHUs) in the context of Thermal Bridging (TB), Thermal Transmittance (T), Mechanical Strength (D), and Air Leakage (L) is rigorously assessed using industry standards like EN 1886 and others. Below is a breakdown of these standards and the testing procedures associated with each classification:

1. Thermal Bridging (TB)

- Standard: EN 1886
- Key Requirement: Measures the thermal bridging factor (TB), ensuring minimal heat transfer through the casing of the AHU.
- Testing: Thermal imaging is used to detect temperature differences across panel surfaces. The TB factor is calculated as the ratio of the surface temperature difference to the ambient air temperature difference. Classified into classes TB1 (best) to TB5 (worst), with TB1 indicating minimal thermal bridging.

2. Thermal Transmittance (T)

- Standard: EN 1886, ISO 6946
- Key Requirement: Determines the U-value (thermal transmittance) of the casing.
- Testing: Panels are exposed to a defined temperature gradient. Heat flow is measured to calculate the U-value (W/m²·K). Lower U-values correspond to better thermal insulation.
    Classification: T1 (best) to T6 (poorest), with T1 indicating superior insulation.

3. Mechanical Strength (D)

- Standard: EN 1886
- Key Requirement: Ensures the casing can withstand operating pressures without permanent deformation.
- Testing: AHU casings are subjected to positive and negative pressures (typically ±2500 Pa).The deflection of panels and framework is measured. Results are categorized into classes D1 (best) to D4 (poorest).

4. Air Leakage (L)

- Standard: EN 1886, EN 1751, ASHRAE 90.1
- Key Requirement: Quantifies the amount of air leakage through the casing and components under pressure.
- Testing: The AHU is pressurised (positive or negative) at defined levels (e.g., 400 Pa, 700 Pa). Leakage rates are measured in cubic meters per second per square meter (m³/s·m²). Results are classified into L1 (best) to L4 (poorest).

Additional Standards and Guidelines
EN 13053 (Performance and Testing of AHUs)

- Focuses on the overall performance of air-handling systems, including energy efficiency and indoor air quality parameters.
- Defines criteria for energy recovery systems, fan efficiency, and air distribution.

ASHRAE 90.1 (Energy Standards for Buildings)

- Sets energy performance benchmarks for HVAC systems.
- Includes air leakage requirements and insulation specifications for AHUs.

Eurovent Certification

- Provides certification for AHUs to ensure compliance with European performance standards.
- Includes testing for TB, T, D, and L classifications to provide transparency and reliability for end-users.

Importance of Compliance Testing

- Energy Efficiency: Minimizes energy loss through thermal bridging and leakage.
- Durability: Ensures long-term structural and functional reliability under operational conditions.
- Regulatory Compliance: Meets legal requirements for building codes and environmental standards.
- Operational Costs: Reduces costs associated with energy loss and maintenance.

At Damvent we design and produce our range of AHU's to achieve; Mechanical Strength: D1, Air Leakage: L1, Thermal transmittance: T2, Thermal Bridging: TB2 ensuring the best balance between Energy Efficiency, Durability and Costs.

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Or get in touch with us: https://damvent.com/en/contacts