**4. Conclusions**

A test tube was designed to allow for verification prior to official testing. Theoretically projected volume leakage values can be compared with the volume flow values measured by the test tube, thereby allowing for an immediate understanding of the accuracy of the measurement results prior to field testing.

Upon analysis, the general differential pressure in the fire scenarios varied from 10 to 15 Pa, considering test duration, operating costs, and the cleanliness conditions of the test bodies (which affects tape adhesion). The operation of measuring 50 Pa differential pressure was excluded under the condition that it does not affect the test results. Therefore, the field test was conducted only for differential pressures of 10 Pa and 25 Pa for the volume leakage measurement.

A comparison test was conducted for this test method and the CNS 15038 [3] method to evaluate the smoke control performance of doors for the same subject, and a statistically independent sample was examined using SPSS [29] software.

The whole test procedure can be completed by two testing personnel within 30 min, without damaging the door or contaminating the environment. It is demonstrated that this method can complete measurements in any environment, and the test results possess certain reliability.

Among the 20 doors tested in the field, only 13 doors passed the field test, thereby demonstrating that the doors installed in the field do not necessarily achieve the same smoke control performance as those in the laboratory, The smoke control performance may deteriorate due to increased gaps between doors and frames or wear and tear of door hinges over time. The above scenarios highlight the need to manage the smoke control performance from the user end in order to ensure the safety of personnel.

Upon many field experiments, the actual leakage is very close to the theoretical values. The volume leakage will increase with enlarged openings or increased pressure differences. In addition to the large leakage rate through the gap beneath the door, other volumetric airflow rates through lockset, hinges, top, and side gaps are very small.

This test method can be directly applied to various doors, including single and double doors, elevator doors, and roll-up doors. In the future, by extending the design principle of the system, the test method can be applied to other fire protection equipment for the inspection of smoke control capabilities, such as building ducts and fire escapes.

**Author Contributions:** Conceptualization, H.-Y.H., C.-Y.L., and Y.-J.C.; data curation, H.-Y.H.; formal analysis, C.-P.L.; Investigation, H.-Y.H.; methodology, H.-Y.H., C.-Y.L., Y.-J.C.; validation, H.-Y.H.; visualization, H.-Y.H.; writing—original draft, H.-Y.H.; writing—review and editing, H.-Y.H. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research received no external funding.

**Institutional Review Board Statement:** Not applicable.

**Informed Consent Statement:** Not applicable.

**Data Availability Statement:** The data are contained within the article. The data presented in this study are available in Figures 5 and 6 and Table 2.

**Conflicts of Interest:** The authors declare no conflict of interest.
