Advising on Double Skin Facade design
The scope of our work was to assist our clients (facade engineers - FMDC) by examining the advantages and disadvantages of (1) fixed external shading in a Single Skin Façade and (2) a second skin (Double Skin Façade (DSF)) Through a comparative study we identified the design parameters that can maximize the potential benefits.
The study focused on 4 thermal zones (north, east, south and west) as at this point it is important to quantify the potential benefits to drive decisions. Once the façade configuration is selected, then a more elaborated study (for the whole building) is necessary for more accurate performance predictions.
To maximize the usability of the DSF cavity, the goal is to maximize the time when the cavity air temperature is between 10°C and 26°C. To achieve this we can control the ventilation openings with dampers; an example of how dampers can improve the cavity air temperature is shown in the middle Graph (green line represents DSF case with dampers). In this case when the outdoor air temperature is below 10°C, the dampers are closed therefore the cavity air temperature is as no ventilation is provided (red line) and when the outdoor air temperature is above 26°C the dampers are fully open and the air temperature is similar to the case with 50mm openings (blue line).