Chapter hvac engineering Fundamentals: Part 1 Introduction

40
T
ABLE
3.8
Cooling
Load
Factors
When
Lights
Ar
e
o
n
for
8
h
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
43.
T
ABLE
3.9
Cooling
Load
Factors
When
Lights
Ar
e
o
n
for
10
h
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
44.
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.

---

41
T
ABLE
3.10
Cooling
Load
Factors
When
Lights
Ar
e
o
n
for
12
h
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
45.
T
ABLE
3.11
Sensible
Heat
CLFs
for
People
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
40.
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.

---

42
T
ABLE
3.12
Sensible-Heat
CLFs
for
Appliances
—
Hooded
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
48.
T
ABLE
3.13
Sensible-Heat
CLFs
for
Appliances
—
Unhooded
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
49.
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
43
Figure 3.5
The sol-air temperature concept.
peak air conditioning load, and efforts were made to reduce the effects.
Reducing the amount of glass has a claustrophobic effect on people,
so much of the effort centered on reducing the transmission through
the glazing material. There are now available a multitude of materi-
als, including heat-absorbing and heat-reflective glass.
The mechanism of solar transmission through glazing is shown in
Fig. 3.6 (p. 53). When direct or diffuse radiation falls on the glazing,
some is reflected. Some radiation is absorbed, heating the glazing ma-
terial and escaping as convective or radiant heat. Some radiation
passes through the glazing after which it is absorbed by materials in
the room, causing a heating effect and thus a cooling load (after some
time delay). If exterior shading is used, only the diffuse solar compo-
nent is effective. If interior shading is used, some additional reflective
and absorptive factors come into play, and the mechanism becomes
even more complex. As indicated, there is also conduction through the
glazing due to the temperature difference between inside and outside.
At certain times of the year, conduction may represent a heat loss.
Many types of glass are treated to increase the reflective and / or
absorptive components. A highly absorptive glazing can become very
hot; then thermal expansion of the glass can create serious problems
unless sufficient flexibility is provided in the support system. Partial
shading of a pane creates thermal stress along the shadow line. In the
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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