等壓雨屏牆（Pressure-equalized Rainscreen Walls）理論在國外至今已發展約六十餘年，從國外文獻可知雨屏牆具有防止雨水滲透與減輕風載等優點，並符合綠建築之節能、減廢目的，適合應用於舊建築物外牆的更新。

　　由於國內少有人從事雨屏牆之試驗與研究，直到2005年，初步建立了雨屏牆等壓性能之實驗成果與參考資料。但根據國外文獻指出，不同的流況將造成雨屏牆等壓性能上的差異，國內目前已進行研究是以均流風場來模擬，因此，本研究試圖以非均流的紊流風場模擬，將試體高度控制於邊界層厚度之內，使試體正面迎風，改變試體中雨屏的透風面積與中空層容積，在不同的風速下，觀察雨屏牆的等壓性能表現，並與國內已有風洞實驗結果比對，探討不同流況對雨屏牆受壓情形與等壓性能之差異。

　　實驗之數據透過統計分析得到以下成果：

一、在非均勻紊流下正面迎風，雨屏表面之壓力分佈隨高度增加而增大，且以中央測點（1-2、2-2、3-2）為各區帶之較大值，壓力最大值均落在測點3-2。
二、在非均勻紊流下正面迎風，透風開口率越大對開放式接縫雨屏牆等壓效果越好；孔徑越大對圓形透風孔雨屏牆等壓效果越好；改變中空層容積對雨屏牆等壓效果則未有明顯的影響關係。
三、在非均勻紊流下正面迎風，雨屏牆透風幾何形狀為條狀透風孔者，其等壓效果較開放式接縫與圓形透風孔為佳。
四、流況之不同，造成雨屏表面壓力分佈情形不同，此結果直接影響雨屏內外壓差大小與位置，造成不同之等壓效果。
五、不同流況造成雨屏牆等壓性能之差異應取△Cp極值分析較為保守；若面版為開放式接縫，受非均流與均流之等壓效果差異約12.5%；若面版為圓形透風孔，受非均流與均流之等壓效果差異約11.4%；若面版為條狀透風孔，受非均流與均流之等壓效果差異約7%；流況改變對條狀透風孔雨屏牆等壓效果影響最小。

　　最後依本實驗分析數據對減輕風載設計之折減係數建立一表供參考，並建議後續相關研究可採用不同之風速剖面指數α值模擬不同之地況，以建立更完整之實驗數據，正確了解建築風場特性，或為未來訂定相關規範之有效參考資料。

　　Pressure-equalized rainscreen walls have been developed for more than about 60 years so far abroad. We could know rainscreen walls have the advantages of preventing the rain penetration and reducing the wind load from the foreign references. The raincreen wall system that saves the sources of energy and reduces construction waste has conformed to the ideal of green building and fitted for renewing old building exterior walls.

　　Because there are much less people doing researches about rainscreen walls internally, the experiment results and data of pressure equalization performance of rainscreen walls have been established until 2005.But according to the foreign references, there will be differences of pressure equalization performance between different flow conditions. The researches experimented internally are in the uniform flow only. Therefore, this research is tried to be experimented in the non-uniform flow, and the height of the test piece is controlled under the height of the boundary layer. Making the test piece at front windward with different wind velocity and changing the venting rate of rainscreen and cavity volume to study pressure equalization performance of rainscreen walls. Comparing with the present results of wind tunnel experiments to explore the differences of pressure equalization performance by different flow conditions at the same time.

　　The following results are presented after statistical analysis of the experiment data:

1.Located at front windward in the non-uniform flow, the pressure measured on the front of the rainscreen increases with the height, and at the central points (1-2、2-2、3-2) is the maximum of each level. The maximal pressure of the whole rainscreen is at the point 3-2 all the time.
2.Located at front windward in the non-uniform flow, if the venting rate is higher, the pressure equalization performance for open joint will be better; if the aperture is bigger, the pressure equalization performance for circular venting hole will be better. Changing the cavity volume does not have the obvious effect on pressure equalization performance.
3.Located at front windward in the non-uniform flow, the pressure equalization performance for striped venting hole is better than for open joint and circular venting hole.
4.The different flow conditions lead to the different pressure distribution on the front of the rainscreen. The result affects the value and location of the pressure difference between the front and back of the rainscreen directly, and brings about different pressure equalization performance.
5.Analysis by choosing △Cp maximum and minimum is more conservative when the different flow conditions lead to the difference of pressure equalization performance. If the panel is the type of open joint, the difference of pressure equalization performance is about 12.5% between in the uniform and non-uniform flow. If the panel is the type of circular venting hole, the difference of pressure equalization performance is about 11.4%. If the panel is the type of striped venting hole, the difference of pressure equalization performance is about 7%.When the flow condition changes, the effect on pressure equalization performance for striped venting hole is the least.

　　As a conclusion, a table regarding reduction factor of applying pressure equalization to reduce wind load is provided according to the data gained from the experiment. This paper suggests that the follow-up researches could choose the different exponent α to simulate the different surface of the earth for building up more experiment data and comprehending the wind field characteristics of buildings, or being the useful references for setting up relative standards in the future.

一、雨屏牆之基礎學理（編號，作者，主題，年份，出處）
1.1，W. A. Dalgliesh and D. W. Boyd，Wind on Buildings，1962，National Research Council of Canada
1.2，W. A. Dalgliesh and W. R. Schriever，Wind pressures on Buildings，1962，National Research Council of Canada
1.3，G. K. Garden，Rain Penetration and its Control，1963，National Research Council of Canada
1.4，U. Ganguli，Wind and Air Pressures on the Building Envelope，1986，National Research Council of Canada
1.5，M. Z. Rousseau，Facts and Fictions of Rain-Screen Walls，1990，Construction Canada
1.6，Bas A. Baskaran, William C. Brown，Dynamic Evaluation of the Building Envelope for Wind and Wind Driven Rain Performance，1995，Journal of Thermal Insulation and Building Envelope
1.7，G. A. Chown, W. C. Brown and G. F. Poirier，Evolution of Wall Design for Controlling Rain Penetration，1997，National Research Council of Canada
1.8，Edmund C. C. Choi, Zhihong Wang，Study on Pressure-Equalization of Curtain Wall Systems，1998，Journal of Wind Engineering and Industrial Aerodynamics
1.9，M. Z. Rousseau, G. F. Poirier and W. C. Brown，Pressure Equalization in Rainscreen Wall Systems，1998，National Research Council of Canada
1.10，K. Suresh Kumar，Pressure Equalization of Rainscreen Walls: a Critical Review，2000，Building and Environment

二、風洞實驗之應用理論
2.1，Van Dyke, Milton，An album of fluid motion，1982，Calif. :Parabolic Press
2.2，H. J. Gerhard F. Janser，Wind Loads on Wind Permeable Facades，1994，Journal of Wind Engineering and Industrial Aerodynamics
2.3，Inculet. D and D. Surry，Optimum Vent Location for Partially-Pressure Rainscreen，1997，Housing Information Center
2.4，Inculet. D, D. Surry and A. G. Davenport，Unsteady Pressure Gradients and Their Implications For Pressure-Equalized Rainscreen，1997，Boundary Layer Wind Tunnel Laboratory, University of Western Ontario
2.5，Jacques Rousseau，A Study of the Rainscreen Concept Applied to Cladding Systems on Wood Frame Walls，1999，Rousseau Canadian Housing Information Center
2.6，Jacques Rousseau，Simulation of Wind-Driven Rain and Wetting Patterns on Buildings，1999，Rousseau Canadian Housing Information Center
2.7，Jacques Rousseau，Laboratory Investigation and Field Monitoring of Pressure-Equalized Rainscreen Walls，1999，CMHC
2.8，黃斌, 許正傑，開放式接縫對雨屏牆中空層風壓之實驗，1996，成大碩論, 台灣
2.9，周榮華, 朱佳仁, 任森柯, 風洞實驗館系統整合測試暨風洞性能驗證研究(II)，2004，內政部建築研究所,台灣
2.10，朱佳仁，工程流體力學，2005，科技圖書,台灣
2.11，黃斌, 鄭佳欣，雨屏牆透風孔幾何形狀對雨屏牆等壓性能之研究，2005，成大碩論, 台灣
2.12，黃斌, 陳兆華，風攻角對雨屏牆等壓性能之研究，2005，成大碩論, 台灣
2.13，建築物耐風設計規範及解說(草案)，2006，內政部,台灣