Internal Wall Cooling by Reversed Airflow in Ventilation Ducts After Building Retrofit: A Case Study of a Higher Education Facility
Artykuł w czasopiśmie
MNiSW
140
Lista 2024
| Status: | |
| Autorzy: | Polak Wiesław, Gaweł Dariusz, Guz Łukasz, Jakubiak Natalia |
| Dyscypliny: | |
| Aby zobaczyć szczegóły należy się zalogować. | |
| Rok wydania: | 2026 |
| Wersja dokumentu: | Drukowana | Elektroniczna |
| Język: | angielski |
| Numer czasopisma: | 19 |
| Wolumen/Tom: | 19 |
| Numer artykułu: | 4580 |
| Strony: | 1 - 22 |
| Impact Factor: | 3,9 |
| Scopus® Cytowania: | 0 |
| Bazy: | Scopus |
| Efekt badań statutowych | TAK |
| Materiał konferencyjny: | NIE |
| Publikacja OA: | TAK |
| Licencja: | |
| Sposób udostępnienia: | Witryna wydawcy |
| Wersja tekstu: | Ostateczna wersja opublikowana |
| Czas opublikowania: | W momencie opublikowania |
| Data opublikowania w OA: | 26 września 2026 |
| Abstrakty: | angielski |
| This study investigated an unusual yet practically significant side effect of the thermal retrofit of educational buildings, namely the intensive cooling of internal walls containing uninsulated ventilation ducts. Malfunctioning gravity ventilation led to a reversal of airflow direction, resulting in the inflow of cold air through internal ducts and a deterioration of thermal comfort in the rooms. The cooled zones were identified during thermographic surveys carried out using a FLIR E8-XT camera. Numerical heat transfer analyses were performed in THERM 8.1 (LBNL), while the thermal performance of the building and its seasonal heating demand were calculated in Audytor OZC (Sankom). Three variants were compared: (1) standard design conditions, (2) scenario accounting for the cooling effect of internal walls due to reverse flow of ventilation air, and (3) mechanical ventilation with heat recovery (MVHR). Under the analysed actual operating conditions, the transmission heat loss increased from 27,479 W to 52,473 W, while the annual heating demand rose by 57.6% from 71.3 to 112.4 kWh/(m3∙year). The indoor air temperature decreased by approximately 3 ÷ 7 °C (depending of the space), while the surface temperature near the ducts fell to 5.1 ÷ 12.6 °C at an outdoor temperature of −13 °C. The implementation of MVHR (η = 75%), compared to current situation, reduced the overall heat loss coefficient by 63.9% from 3934.225 to 1417.825 W/K and the annual heating demand by 70.3% from 112.4 to 33.3 kWh/(m3∙year). The results confirm that uncontrolled airflow through internal ventilation ducts may lead to substantial heat losses and localised cooling zones in building elements, effectively acting as thermal bridges. |
