Question

Multiple choice question:

Enclosure design of internal-load dominated buildings is:

a.  not a critical consideration compared with HVAC system design.

b.  guided by window-to-wall ratio, window and glazing properties, and airtightness.

c.  based more on rejecting solar gains than addressing hygrothermal issues.

d.  a & b

e.  b & c

Answer 1

Answer : Enclosure design of internal-load dominated buildings is:

• (c) based more on rejecting solar gains than addressing hygrothermal issues.

Buildings that have high occupant densities and high internal gains from lighting and/or equipment are considered internal-load dominated buildings. Sometimes these are also referred to as a core-load dominated building. Regardless of climate type, the internal heat generation puts high demands on ventilation and cooling that are further driven by solar gains. For this building type, efficient means of rejecting excess heat generation translate into building enclosures that are typically less thermally efficient than effective at reducing solar gains by deploying shading devices and selecting appropriate optical properties of glazing. Different fenestration and shading strategies can also be deployed corresponding to the solar orientation of each face of the facade. Office towers and large retail facilities like shopping malls are notable examples of internal-load dominated buildings. Integration of the building enclosure with the HVAC systems is critical for achieving high performance in these types of buildings.