Retractable Awnings Keep You Cool

Tables 29–32 show the impact

of awnings on a typical house in
St. Louis, Missouri with different
orientation conditions. The impact
varies depending on the type of
window glazing and whether the
awnings are in place 12 months per
year or only in the summer.
For a house with windows equally
distributed on the four orientations,
Table 29 shows the annual
heating and cooling energy use as
well as the peak electricity demand
for each combination of glazing and
shading condition. The table also
shows the impact on the total cost
of heating and cooling. In each case,
the table shows the percent savings
compared to the unshaded condition.
As shown in Table 29, the awnings
reduce the cooling energy
14–17 percent compared to a completely
unshaded case. The actual
savings are greatest with clear glazing
(A) and least with low-solargain
low-E windows (C). Because
awnings block passive solar gain
in winter, heating energy increases
if the awnings remain in place 12
months a year. Removing or retracting
the awnings in winter while
deploying them in summer results
in the lowest energy use.
The total cost of heating and
cooling is reduced 1–3 percent in St.
Louis when awnings are only used
in the summer, but the savings from
awnings are diminished if they
remain in place 12 months a year.
Table 29 also shows that awnings
reduce peak electricity demand by
11–16 percent in St. Louis. This may
contribute to the ability to downsize
the mechanical cooling system. The
actual savings are greatest with
clear double glazing (A) and least
with low-solar-gain low-E windows
(C).
Tables 42, 43 and 44 show results
for houses in St. Louis with the windows
predominantly facing to the
east, south, and west, respectively.
The cooling energy savings from
awnings is greatest on the east- and
west-facing orientations. The peak
demand reduction from awnings is
greatest on the west-facing orientation.Tables 29–32 show the impact

of awnings on a typical house in

St. Louis, Missouri with different

orientation conditions. The impact

varies depending on the type of

window glazing and whether the

awnings are in place 12 months per

year or only in the summer.

For a house with windows equally

distributed on the four orientations,

Table 29 shows the annual

heating and cooling energy use as

well as the peak electricity demand

for each combination of glazing and

shading condition. The table also

shows the impact on the total cost

of heating and cooling. In each case,

the table shows the percent savings

compared to the unshaded condition.

As shown in Table 29, the awnings

reduce the cooling energy

14–17 percent compared to a completely

unshaded case. The actual

savings are greatest with clear glazing

(A) and least with low-solargain

low-E windows (C). Because

awnings block passive solar gain

in winter, heating energy increases

if the awnings remain in place 12

months a year. Removing or retracting

the awnings in winter while

deploying them in summer results

in the lowest energy use.

The total cost of heating and

cooling is reduced 1–3 percent in St.

Louis when awnings are only used

in the summer, but the savings from

awnings are diminished if they

remain in place 12 months a year.

Table 29 also shows that awnings

reduce peak electricity demand by

11–16 percent in St. Louis. This may

contribute to the ability to downsize

the mechanical cooling system. The

actual savings are greatest with

clear double glazing (A) and least

with low-solar-gain low-E windows

(C).

Tables 42, 43 and 44 show results

for houses in St. Louis with the windows

predominantly facing to the

east, south, and west, respectively.

The cooling energy savings from

awnings is greatest on the east- and

west-facing orientations. The peak

demand reduction from awnings is

greatest on the west-facing orientation.Tables 29–32 show the impact of awnings on a typical house in St. Louis, Missouri with different orientation conditions. The impact varies depending on the type of window glazing and whether the awnings are in place 12 months per year or only in the summer. For a house with windows equally distributed on the four orientations, Table 29 shows the annual heating and cooling energy use as well as the peak electricity demand for each combination of glazing and shading condition. The table also shows the impact on the total cost of heating and cooling. In each case, the table shows the percent savings compared to the unshaded condition. As shown in Table 29, the awnings reduce the cooling energy 14–17 percent compared to a completely unshaded case. The actual savings are greatest with clear glazing (A) and least with low-solargain low-E windows (C). Because awnings block passive solar gain in winter, heating energy increases if the awnings remain in place 12 months a year. Removing or retracting the awnings in winter while deploying them in summer results in the lowest energy use. The total cost of heating and cooling is reduced 1–3 percent in St. Louis when awnings are only used in the summer, but the savings from awnings are diminished if they remain in place 12 months a year. Table 29 also shows that awnings reduce peak electricity demand by 11–16 percent in St. Louis. This may contribute to the ability to downsize the mechanical cooling system. The actual savings are greatest with clear double glazing (A) and least with low-solar-gain low-E windows (C). Tables 42, 43 and 44 show results for houses in St. Louis with the windows predominantly facing to the east, south, and west, respectively. The cooling energy savings from awnings is greatest on the east- and west-facing orientations. The peak demand reduction from awnings is greatest on the west-facing orientation.