SIST EN ISO 10077-2:2017 PDF

Overview

SIST EN ISO 10077-2:2017 - based on ISO 10077-2:2017 - specifies a numerical method for calculating the thermal transmittance of window, door and shutter frame profiles and the linear thermal transmittance of their junctions with glazing or opaque panels. The standard provides input data, calculation procedures and validation criteria for numerical programs used to determine frame U‑values and related thermal metrics. It also covers shutter profiles and components such as roller shutter boxes and blinds, and sits within the EPB standards framework (see ISO 52000‑1).

Key topics and technical requirements

• Scope of calculation
  • Determination of frame thermal transmittance (U‑value) and linear thermal transmittance (ψ) at frame‑glazing or frame‑panel junctions.
  • Evaluation of thermal resistance for shutter profiles and roller shutter boxes.
• Methods and models
  • Numerical solution of heat transfer in frame cross‑sections.
  • Treatment of cavities using the radiosity method and the single equivalent thermal conductivity approach.
  • Separation of conduction/convection and radiation phenomena.
• Input data and parameters
  • Geometrical characteristics of profiles.
  • Material thermal conductivity and emissivity values.
  • Boundary conditions (general and specific for roller shutter boxes).
  • Referenced default material and surface resistance data provided in annexes.
• Validation and reporting
  • Criteria and test examples for validation of calculation programs (normative annexes contain validation cases).
  • Required report content and templates for reproducibility (input/data sheets, output presentation).
• Exclusions
  • Does not account for solar radiation, heat transfer from air leakage, three‑dimensional effects (e.g., pinpoint metallic connections) or thermal bridge effects between the frame and building structure.

Practical applications and users

• Window, door and shutter manufacturers seeking standardized U‑value and ψ‑value calculations for product development, comparison and CE/energy labeling.
• Façade and building envelope engineers performing thermal design and detailing of junctions.
• Software developers implementing thermal simulation tools for frame cross‑sections.
• Certification bodies, energy assessors and testing laboratories validating thermal performance claims in accordance with EPB requirements.

Related standards

• ISO 10077‑1 (overall framework for calculation of thermal transmittance)
• ISO 52000‑1 (modular structure of EPB standards / energy performance of buildings)
• Other EPB standards referenced for building energy performance compliance

Keywords: ISO 10077-2:2017, thermal performance of windows, thermal transmittance, numerical method for frames, radiosity method, linear thermal transmittance, roller shutter boxes, frame U-value, EPB standards.