GTI GTI660 Building Exterior Window Air Permeability Testing System

Overview

The GTI GTI660 Building Exterior Window Air Permeability Testing System is a field-deployable, calibrated instrumentation platform engineered for quantitative evaluation of air leakage performance in installed building façade windows and curtain wall assemblies. It operates on the principle of controlled differential pressure testing—establishing a sealed static pressure chamber (via a purpose-designed window-mounted sealing frame) adjacent to the test specimen, then inducing precise positive or negative pressure differentials across the window plane while measuring volumetric airflow rates required to maintain those differentials. This methodology directly implements the physical definition of air permeability per ISO 9972 and aligns with the procedural requirements of GB/T 7106–2019 (equivalent to EN 12152 and ASTM E283), enabling classification of window air tightness according to standardized grading criteria (Classes 1–8). The system integrates a variable-speed blower unit, microprocessor-based pressure and flow sensing, environmental parameter monitoring (ambient temperature, barometric pressure), and real-time calculation of normalized air leakage rates (m³/(h·m²) at 10 Pa).

Key Features

• Bi-directional pressure control (±0 to ±500 Pa) with rapid stabilization and minimal overshoot, supporting both pressurization and depressurization protocols as required by GB/T 7106–2019 Section 6.3.
• High-accuracy volumetric airflow measurement (1–60 m³/h) using calibrated orifice-based flow sensing, traceable to national metrological standards, with uncertainty budget compliant with ISO/IEC 17025 calibration practices.
• Dual-sensor environmental compensation: simultaneous acquisition of ambient temperature (±0.5 °C) and atmospheric pressure (±2% of reading), automatically applied to normalize measured leakage rates to standard reference conditions (10 Pa, 20 °C, 101.3 kPa).
• Integrated real-time leakage quantification: the control host computes and displays air permeability values (q₁ and q₂ per GB/T 7106–2019 Annex B), applies classification logic per Table 3, and outputs pass/fail status against specified performance grades.
• Robust field ergonomics: blower unit features rear-mounted high-strength neodymium magnets for secure mounting onto adjustable-height support stands; control host includes low-power design (AA battery or USB-C 5 V operation) and compact form factor (<250 g) for handheld use during multi-point site surveys.
• Dynamic data smoothing via moving average algorithm (configurable window size) mitigates transient turbulence effects without compromising temporal resolution—critical for reliable measurements in unconditioned outdoor or semi-enclosed construction environments.

Sample Compatibility & Compliance

The GTI660 accommodates standard residential and commercial window configurations—including casement, tilt-turn, sliding, and fixed glazing units—within nominal dimensions up to 3.0 m × 3.0 m when used with optional extended sealing frames. Its modular waveguide coupling system (2.5 m reinforced corrugated hose with quick-connect fittings) ensures leak-tight integration with the pressure chamber regardless of window geometry or substrate irregularity. All measurement procedures, hardware tolerances, and software algorithms conform to the normative testing framework defined in GB/T 7106–2019 “Testing method for air permeability, watertightness and wind load resistance of building exterior windows and doors”, as well as supplementary standards JG/T 211–2007 (on-site inspection methodology) and GB/T 31433–2015 (general technical requirements for building envelope testing equipment). The system supports audit-ready documentation generation for quality assurance under GB/T 19001 (ISO 9001) and construction supervision workflows aligned with China’s Construction Engineering Quality Supervision Regulations.

Software & Data Management

The GTI660 communicates bidirectionally with GTI’s proprietary Windows-based desktop application via RS485 (wired) or IEEE 802.11 b/g/n Wi-Fi (wireless), enabling remote configuration, real-time telemetry streaming, and post-test report generation. The software enforces structured test session logging—including operator ID, project name, window ID, installation date, climatic conditions, raw sensor time-series, and final classification—stored in encrypted SQLite databases compliant with basic GLP data integrity principles. Export options include PDF test certificates (with digital signature fields), CSV time-series datasets, and XML-formatted records compatible with municipal building information modeling (BIM) handover protocols. Firmware updates are delivered via signed binary packages with SHA-256 verification, ensuring traceability and version control across fleet deployments.

Applications

• On-site compliance verification of newly installed windows prior to building handover (per GB 50300–2013 acceptance criteria).
• Post-renovation air barrier performance validation in energy retrofit projects targeting DBJ01–602–2004 or local green building rating systems (e.g., LEED v4.1 EA Prerequisite: Minimum Energy Performance).
• Quality control auditing during mass production of fenestration products in factory settings, supporting ISO 9001 Clause 8.6 release verification.
• Research-grade leakage mapping of complex façade mock-ups in laboratory environments, where synchronized pressure ramping and multi-point flow profiling are required.
• Forensic investigation of moisture intrusion pathways linked to air-driven vapor transport through poorly sealed window perimeters.

FAQ

What standards does the GTI660 explicitly support?
It is fully configured to execute test sequences and classification logic per GB/T 7106–2019, JG/T 211–2007, and GB/T 31433–2015. Its pressure and flow metrology chain is traceable to CNAS-accredited calibration laboratories.
Can the system operate without external power at the test site?
Yes—the control host runs on four AA alkaline batteries (≥12 hours continuous operation) or a portable 5 V USB power bank; the blower unit requires AC 220 V but may be powered via site generators or temporary distribution panels.
Is third-party calibration documentation provided with shipment?
Each unit ships with a factory calibration certificate indicating as-found/as-left values for pressure, airflow, temperature, and barometric sensors, referenced to national primary standards maintained by LNMC (Liaoning Metrology Institute).
How is data integrity ensured during wireless transmission?
Wi-Fi communication employs TLS 1.2 encryption for all command-and-control packets; sensor data payloads are transmitted over UDP with cyclic redundancy check (CRC-32) validation and automatic retransmission of corrupted frames.
Does the system support automated pass/fail decisioning based on project specifications?
Yes—users define target air permeability limits (e.g., q₁ ≤ 1.5 m³/(h·m²)) within the software; the system compares real-time calculated values and flags nonconformance with visual alerts and timestamped log entries.