Determining Equipment Accuracy
Accuracy in pressure and flow testing requires a clear understanding of both gauge and fan performance:
Retrotec calibrates all fans and gauges in an ISO/IEC 17025 accredited laboratory, ensuring traceability to NIST standards.
Field checks, such as cross-port gauge comparison and fan verification procedures, help confirm instrument accuracy in situ.
Gauge & Fan Calibration Requirements
Ensure your tools remain reliable over time:
DM‑32 gauges require calibration every 5 years (or immediately if a field check fails).
Retrotec fans also follow a 5-year calibration interval.
These intervals are manufacturer-recommended; energy standards (e.g., ASTM, ATTMA, ISO) may mandate different schedules—always confirm with your applicable protocol.
Reducing Uncertainty in Test Results
Multiple factors affect test precision. To minimize uncertainty (target ≤ ±5%, even ≤3–4%):
Use time averaging longer than baseline capture to smooth readings
Record multiple baseline points to normalize environmental drift
Ensure correct fan selected and proper range ring/plate installed
Use stable tubing and avoid disturbances like tube movement or wind
A Monte Carlo simulation study referenced in field calibration literature confirmed that careful process control can reduce measurement uncertainty substantially.
Why QA ≥ QC = Better Accuracy
Accuracy in pressure and flow testing requires a clear understanding of both gauge and fan performance:
Retrotec calibrates all fans and gauges in an ISO/IEC 17025 accredited laboratory, ensuring traceability to NIST standards.
Field checks, such as cross-port gauge comparison and fan verification procedures, help confirm instrument accuracy in situ.
Identifying the Right Process for the Right Test
| Test Scenario | Recommended Approach |
|---|---|
| Standard single-family envelope | Use FanTestic with DM‑32 and single blower fan; multi-point test if precision is critical |
| Large building | Multi-point, multi-fan testing (≥2–3 fans) controlled by DM‑32X and FanTestic software |
| Duct leakage to outdoors | Use ±25 Pa depressurization or pressurization with DucTester and proper range plate |
| Exhaust or ventilation flow test | Use TEC Flow Meter, TrueFlow®, or convert blower-door/fan as powered flow hood |
