通風屋頂節能效益之實例研究

A Case Study on Energy Conservation of Roof Ventilation

陳昭瀚(Zau-Han Chen)

指導教授 ： 李魁鵬

國立臺北科技大學/機電學院/能源與冷凍空調工程系碩士班/碩士(2007年)

摘要

本論文實際案例為座落於花蓮地區一具有設計誘導式通風冷卻手法之建築，屋頂與天花板的空間內部設計換氣管道間，並銜接穿越RC外牆之換氣風管與外氣導通，形成通風屋頂，因此天花板內的空間與外氣產生對流，將屋頂所吸收的太陽輻射熱導出，可降低太陽輻射熱對室內舒適度的影響。本論文採用美國FLUENT Inc.所開發以有限體積法(Finite Volume Method，FVM)為架構的計算流體力學模擬軟體Airpak 2.1，進行電腦模擬分析。探討直徑15cm、25cm、35cm與45cm之穿越RC外牆換氣風管，對於通風屋頂內部之溫度分佈、空氣流速、氣流流場等，評估其節能與室內人員舒適度改善之效益。

本論文依花蓮地區四季氣候條件下，固定換氣管道間尺寸，模擬分析不同穿越RC外牆之換氣風管開口的通風效益對於室內舒適度的影響，其中採用換氣風管直徑45cm時，春季室內平均舒適度指標約0.41、夏季室內平均舒適度指標約1.92、秋季室內平均舒適度指標約1.02、冬季室內平均舒適度指標則為0.13。若採用通風屋頂之建築相較於無通風屋頂之建築，最高可節省約5.04%之空調耗電，總耗電約節省2.63%；約可降低66.48%之屋頂尖峰熱負荷，屋頂全年總熱得最大則減幅46.55%。

關鍵字

通風屋頂 ； 節能 ； CFD ； PMV ； 模擬

並列摘要

In this research, the analysis case is an actual building with passive cooling design by roof ventilation and located at Hualien area. The roof ventilation is designed as a ventilated plenum between the roof and ceiling. The plenum has horizontal vent tubes which traverse and are buried in the beam to allow air flow between rooms. Several vertical vent shafts penetrating the roof and horizontal vent tubes penetrating the plenum exterior walls are designed to induce the outside air and to cool the plenum where are accumulated with the heat from the roofs. The vented roof will reduce the influence of solar radiation to the indoor thermal comfort.

The research includes the temperature measurements of the ventilated roof and rooms and also adopted the software of computational fluid dynamics program-Airpak 2.1 which is based on FVM (Finite Volume Method, developed by FLUENT Inc. in the U.S.) to do computer simulation analysis. The temperature distributions and velocity profiles of the building for different designs of tube section area are investigated and the benefit of ventilation roof are evaluated by energy saving and thermal comfort index in the four seasons of a year.
The study is based on the same size of the vertical vent shafts and do simulation analysis of the ventilation efficiency for the different opening size of the horizontal vent tubes penetrating the plenum exterior walls. The results indicate the average of PMV comfort index for occupants inside is 0.41 in spring, 1.92 in summer, 1.02 in autumn and 0.13 in winter on the condition of the vent tubes of 45 cm in diameter. If comparing the ventilated roof with non-ventilated roof, the electricity energy saving of the air conditioning system is about 5.04%. The total building electricity energy saving is about 2.63%. The peak conduction cooling load of the ventilated roof could reduce about 66.48% and the annual conduction cooling could reduce about 46.55%.

並列關鍵字

Roof Ventilation, ； Energy saving ； CFD ； PMV ； Simulation

參考文獻

[1] ASHRAE Handbook Fundamentals ,2005 , American Society of Heating Refrigerating and Air-conditioning Engineers.

[2] ASHREA/IES Standard 90.1-2004 , Energy Efficient Design of New Buildings Except Low-rise Residential Buildings, American Society of Heating Refrigerating and Air-conditioning Engineers.

[3] ASHREA/IES Stamdard 55-2004 ,Thermal Environmental Conditions for Human Occupancy, American Society of Heating Refrigerating and Air-conditioning Engineers.

[6] Gan, G. A parametric study of Trombe walls for passive cooling of buildings. Energy and Buildings, 27, 1998, pp. 37-43.

[18] 邱瓊萱，通風管管頂型式對室內通風效益影響之研究，碩士論文，國立成功大學建築研究所，2004。