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Thermal Permeability in Windows and Doors

Standard: EN ISO 10077-1:2007

Standard Information

  • Standard Number: EN ISO 10077-1:2007
  • Title: Thermal performance of windows, doors and shutters - Calculation of thermal transmittance
  • Part 1: General
  • Status: Current

Thermal Transmittance Values

Key Parameters

  • Uw: Overall thermal transmittance of window
  • Ud: Overall thermal transmittance of door
  • Ug: Thermal transmittance of glazing
  • Uf: Thermal transmittance of frame
  • Ψg: Linear thermal transmittance of glazing edge

Calculation Methods

The standard provides calculation methods for:

  • Single and multiple glazed units
  • Various frame materials
  • Different panel configurations
  • Thermal bridges
  • Air cavity effects

Performance Classes

Typical thermal transmittance values (W/m²K):

  • Basic: Uw/Ud ≤ 2.6
  • Improved: Uw/Ud ≤ 1.8
  • Enhanced: Uw/Ud ≤ 1.4
  • High Performance: Uw/Ud ≤ 1.0
  • Passive House: Uw/Ud ≤ 0.8

Influencing Factors

  • Frame material and design
  • Glazing type and configuration
  • Spacer materials
  • Panel construction
  • Installation method
  • Size and proportions

Application Guidelines

Recommended Values by Building Type

  • Residential Buildings: 1.4-1.8 W/m²K
  • Commercial Buildings: 1.6-2.2 W/m²K
  • Low Energy Houses: 0.8-1.2 W/m²K
  • Passive Houses: ≤ 0.8 W/m²K

Documentation Requirements

Required documentation includes:

  • Calculation reports
  • Component specifications
  • Test certificates
  • Installation instructions
  • Maintenance guidelines

Verification Methods

  • Calculation according to standards
  • Hot box testing
  • Computer simulations
  • Field measurements
  • Thermal imaging

Important Considerations:

  • Consider local climate conditions
  • Check national building regulations
  • Verify energy efficiency requirements
  • Ensure proper installation
  • Account for thermal bridging