|
55
T
ABLE
3.22
Shading
Coef
ficients
for
Single
Glass
with
Indoor
Shading
by
V
enetian
Blinds
or
Roller
Shades
3
32
1
4
1
4
1
2
1
2
1
8
1
8
3
16,
7
32
3
16,
1
4
3
16,
1
4
1
8,
3
8
7
32
*
Refer
to
manufacturer’s
literature
for
values.
†
F
o
r
vertical
blinds
with
opaque
white
and
beige
louvers
in
the
tightly
closed
position,
SC
is
0.25
and
0.29
when
used
with
glass
of
0.71
to
0.80
transmittance.
‡
Refers
to
gra
y,
bronze,
and
green
tinted
heat-absorbing
glass.
§
SC
for
glass
with
no
shading
device.
S
O
URCE
:
Copyright
1993,
American
Society
of
Heating,
Refrigerating
and
Air
Conditioning
Engineers,
Inc.,
www
.ashrae.org.
Abstracted
by
permission
from
ASHRAE
Handbook,
1993
Fundamentals,
Chap.
27,
T
able
28.
(Later
editions
ha
ve
more
extensive
data.)
Design Procedures: Part 1
Downloaded from Digital Engineering Library @ McGraw-Hill (www.digitalengineeringlibrary.com)
Copyright © 2004 The McGraw-Hill Companies. All rights reserved.
Any use is subject to the Terms of Use as given at the website.
56
T
ABLE
3.23
Shading
Coef
ficients
for
Insulating
Glass*
with
Indoor
Shading
by
V
enetian
Blinds
or
Roller
Shades
1
4
1
4
3
32,
1
8
*
Refers
to
factory-fabricated
units
with
3
⁄
16
,
1
⁄
4
,o
r
1
⁄
2
-in
airspace,
or
to
prime
windows
plus
storm
windows.
†
Refer
to
manufacturer’s
literature
for
exact
values.
‡
F
o
r
vertical
blinds
with
opaque
white
or
beige
louvers,
tightly
closed,
SC
is
approximately
the
same
as
for
opaque
white
roller
shades.
§
Refers
to
bronze,
or
green
tinted,
heat-absorbing
glass.
ن
SC
for
glass
with
no
shading
device.
S
O
URCE
:
Copyright
1993,
American
Society
of
Heating,
Refrigerating
and
Air
Conditioning
Engineers,
Inc.,
www
.ashrae.org.
Reprinted
by
permission
from
ASHRAE
Handbook,
1993
Fundamentals,
Chap.
27,
T
able
29.
(Later
editions
ha
ve
more
extensive
data.)
Design Procedures: Part 1
Downloaded from Digital Engineering Library @ McGraw-Hill (www.digitalengineeringlibrary.com)
Copyright © 2004 The McGraw-Hill Companies. All rights reserved.
Any use is subject to the Terms of Use as given at the website.
57
T
ABLE
3.24
Shading
Coef
ficients
for
Double
Glazing
with
Between-Glass
Shading
1
4
1
4
3
32,
1
8
*
Refer
to
manufacturer’s
literature
for
exact
values.
†
Refers
to
gra
y,
bronze,
and
green
tinted
heat-absorbing
glass.
S
O
URCE
:
Copyright
1993,
American
Society
of
Heating,
Refrigerating
and
Air
Conditioning
Engineers,
Inc.,
www
.ashrae.org.
Reprinted
by
permission
from
ASHRAE
Handbook,
1993
Fundamentals,
Chap.
27,
T
able
30.
(Later
editions
ha
ve
more
extensive
data.)
Design Procedures: Part 1
Downloaded from Digital Engineering Library @ McGraw-Hill (www.digitalengineeringlibrary.com)
Copyright © 2004 The McGraw-Hill Companies. All rights reserved.
Any use is subject to the Terms of Use as given at the website.
58
T
ABLE
3.25
Shading
Coef
ficients
for
Single
and
Insulating
Glass
with
Draperies
1
2
1
4
1
2
1
4
1
2
SC for inde
x letters in Fig. 3.8 (p. 70)
S
O
URCE
:
Copyright
1997,
American
Society
of
Heating,
Refrigerating
and
Air
Conditioning
Engineers,
Inc.,
www
.ashrae.org.
Reprinted
by
permission
from
ASHRAE
Handbook,
1997
Fundamentals,
Chap.
29,
T
able
29.
Design Procedures: Part 1
Downloaded from Digital Engineering Library @ McGraw-Hill (www.digitalengineeringlibrary.com)
Copyright © 2004 The McGraw-Hill Companies. All rights reserved.
Any use is subject to the Terms of Use as given at the website.
Design Procedures: Part 1
59
TABLE
3.26 Maximum Solar Heat Gain Factors, Btu / (h
䡠
ft
2
), for Sunlit Glass,
North Latitudes
Because of the effects of solar radiation and storage in the glass,
the conduction heat gain must be treated in a manner similar to that
used for walls and roofs. The design temperature difference must be
corrected as shown in Table 3.31 (p. 68). Then the cooling load from
conduction (and convection) can be calculated from
Design Procedures: Part 1
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Copyright © 2004 The McGraw-Hill Companies. All rights reserved.
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60
Chapter Three
TABLE
3.26 (
Continued
)
q
⫽
U
⫻
A
⫻
CLTD
(3.5)
This is added to the direct and diffuse solar load above to yield the
total cooling load for fenestration.
The criteria sheets must include the necessary data for each ori-
entation, glass-shading combination, and time of day to be used in the
calculations.
Design Procedures: Part 1
Downloaded from Digital Engineering Library @ McGraw-Hill (www.digitalengineeringlibrary.com)
Copyright © 2004 The McGraw-Hill Companies. All rights reserved.
Any use is subject to the Terms of Use as given at the website.
Design Procedures: Part 1
61
TABLE
3.26 (
Continued
)
3.5.5
Infiltration
The heat gain or loss due to infiltration is impossible to calculate with
any assurance of accuracy. The inaccuracy results from three factors
which are outside the control of the HVAC designer: building construc-
tion, chimney effects, and wind direction and velocity.
No building is tight. Windows, even when fixed in place, leak air
around the frames and gaskets. Doors leak air even when closed, and
Design Procedures: Part 1
Downloaded from Digital Engineering Library @ McGraw-Hill (www.digitalengineeringlibrary.com)
Copyright © 2004 The McGraw-Hill Companies. All rights reserved.
Any use is subject to the Terms of Use as given at the website.
62
Chapter Three
TABLE
3.26 (
Continued
)
SOURCE
: Copyright 1997, American Society of Heating, Refrigerating and Air Conditioning
Engineers, Inc., www.ashrae.org. Abstracted by permission from ASHRAE Handbook,
1997
Fundamentals,
Chap. 29, Tables 15 through 20. Data are for values at noon. Tables in source
provide values at other times.
Design Procedures: Part 1
Downloaded from Digital Engineering Library @ McGraw-Hill (www.digitalengineeringlibrary.com)
Copyright © 2004 The McGraw-Hill Companies. All rights reserved.
Any use is subject to the Terms of Use as given at the website.
63
T
ABLE
3.27
Cooling
Load
Factors
for
Glass
without
Interior
Shading,
North
Latitudes
Design Procedures: Part 1
Downloaded from Digital Engineering Library @ McGraw-Hill (www.digitalengineeringlibrary.com)
Copyright © 2004 The McGraw-Hill Companies. All rights reserved.
Any use is subject to the Terms of Use as given at the website.
64
T
ABLE
3.27
(
Continued
)
L
⫽
Light
construction:
frame
exterior
w
all,
2-in
concrete
floor
slab,
approximately
30
lb
of
material
/f
t
2
of
floor
area.
M
⫽
Medium
construction:
4-in
concrete
exterior
w
all,
4-in
concrete
floor
slab,
approximately
70
lb
of
building
material
/f
t
2
of
floor
area.
H
⫽
Hea
vy
construction:
6-in
concrete
exterior
w
all,
6-in
concrete
floor
slab,
approximately
130
lb
of
building
materials
/f
t
2
of
floor
area.
S
O
URCE
:
Copyright
1989,
American
Society
of
Heating,
Refrigerating
and
Air
Conditioning
Engineers,
Inc.,
www
.ashrae.org.
Abstracted
by
permission
from
ASHRAE
Handbook,
1989
Fundamentals,
Chap.
26,
T
able
36.
T
ABLE
3.28
Cooling
Load
Factors
for
Glass
with
Interior
Shading,
North
Latitudes
S
O
URCE
:
Copyright
1989,
American
Society
of
Heating,
Refrigerating
and
Air
Conditioning
Engineers,
Inc.,
www
.ashrae.org.
Abstracted
by
permission
from
ASHRAE
Handbook,
1989
Fundamentals,
Chap.
26,
T
able
39.
Design Procedures: Part 1
Downloaded from Digital Engineering Library @ McGraw-Hill (www.digitalengineeringlibrary.com)
Copyright © 2004 The McGraw-Hill Companies. All rights reserved.
Any use is subject to the Terms of Use as given at the website.
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