Screens should be located in all areas where insects, rodents, or
birds could prove to be an annoyance or damage the contents of a room. Unless
the specific requirements of the local environment dictate otherwise, 14-wire
screen should be used. This allows greater interior airflow than higher
density mesh and should prevent most insects from entering the building. It
is possible in highrise buildings to eliminate screens on the upper floors
(above four stories) if the designer and Activity mutually agree to its
When a building is located adjacent to a highway, parking lot, or
other dusty area, screens may assist in reducing the infiltration of windborne
dust, dirt, and other debris. The use of screens for this purpose, however,
must not interfere with requirements for adequate ventilation. Screens should
be maintained on a regular basis.
Thermal Considerations. Windows usually contribute the major
portion of solar heat transmission into a building. For minimum solar gain,
openings should be located primarily on the north and south sides rather than
the east and west sides, and all openings shall be completely shaded between 8
am and 6 pm solar time during the cooling season to minimize heat gain (refer
to para. 4.5.6).
Separation of the light-admitting, view, and ventilating purposes
of windows may be advantageous (refer to para. 4.5.5).
Separation of Functions. It is possible to separate the
light-admitting (and therefore heat-admitting) and ventilating purposes of
windows, so that there can be larger inlet and outlet areas with lower total
solar gain. This separation is especially useful in tradewind areas where the
predominant wind directions, from the northeast to southeast, are difficult to
shade effectively. It may be preferable to use shaded, opaque openings for
ventilation on the easterly exposures and separate glazed windows for view and
daylight on the north and south facing exposures, which may or may not be
operable as well.