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Slide Nr. 1 of 13 Slides
AIR-CONDITIONING PROCESSES
Mon 2:04:28 PM
Chapter 2:
Psychrometry and Air-Conditioning
Dr. Eng. Sameh Shaaban
5 December 2009
Air is commonly heated andhumidified in winter and cooledand dehumidified in summer.
Slide Nr. 2 of 13 Slides
Simple Heating and Cooling (ωωωω = constant)
Mon 2:04:28 PM
Chapter 2:
Psychrometry and Air-Conditioning
Dr. Eng. Sameh Shaaban
5 December 2009
tch paa =
Enthalpy of mixture per unit mass of dry air Cooling
Slide Nr. 3 of 13 Slides
Heating with Humidification
Mon 2:04:28 PM
Chapter 2:
Psychrometry and Air-Conditioning
Dr. Eng. Sameh Shaaban
5 December 2009
Slide Nr. 4 of 13 Slides
Cooling with Dehumidification
Mon 2:04:28 PM
La
ten
t H
ea
t
Chapter 2:
Psychrometry and Air-Conditioning
Dr. Eng. Sameh Shaaban
5 December 2009
xSensible Heat
La
ten
t H
ea
t
loadheatTotal
loadheatSensible
hh
hh
21
2x =−
−
Slide Nr. 5 of 13 Slides
Evaporative Cooling
Mon 2:04:28 PM
Chapter 2:
Psychrometry and Air-Conditioning
Dr. Eng. Sameh Shaaban
5 December 2009
Slide Nr. 6 of 13 Slides
Adiabatic Mixing of Airstreams
Mon 2:20:10 PM
Chapter 2:
Psychrometry and Air-Conditioning
Dr. Eng. Sameh Shaaban
5 December 2009
Slide Nr. 7 of 13 Slides
Adiabatic Mixing of Airstreams
Mon 2:20:10 PM
1a
123 m
1
hhh
&+
+=
1a
123 m
1&
+
ω+ω=ω
Chapter 2:
Psychrometry and Air-Conditioning
Dr. Eng. Sameh Shaaban
5 December 2009
2a
1a
m
m1
&
&+
2a
1a
m
m1
&
&+
Slide Nr. 8 of 13 Slides
Summer Air Conditioning
Mon 2:20:10 PM
23
43
23
43
hh
hhr
ω−ω
ω−ω=
−
−=
r is the mass flow of dry recirculated air per unit mass flow of dry air supplied to the room.
Chapter 2:
Psychrometry and Air-Conditioning
Dr. Eng. Sameh Shaaban
5 December 2009
A4Line
A5LinefactorbypassCoil
−
−=
A4Line
54LinefactorContact
−
−=
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Winter Air Conditioning
Mon 2:20:10 PM
A5Line
65LineefficiencyWasher
−
−=
( )56as mm ω−ω= &&
Chapter 2:
Psychrometry and Air-Conditioning
Dr. Eng. Sameh Shaaban
5 December 2009
( )56ass hhmhm −= &&
( )( )56
56s
hhh
ω−ω
−=
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Cooling Towers
Mon 2:20:10 PM
Induced-draft counter flow cooling tower
Chapter 2:
Psychrometry and Air-Conditioning
Dr. Eng. Sameh Shaaban
5 December 2009
Packing
Slide Nr. 11 of 13 Slides
Cooling Towers
Mon 2:20:10 PM
Natural-draft cooling tower
Chapter 2:
Psychrometry and Air-Conditioning
Dr. Eng. Sameh Shaaban
5 December 2009
Slide Nr. 12 of 13 SlidesMon 2:20:10 PM
Example 15.5:
Pg @ 30°C=0.0424 bar
ωωωω3333 = 0.01086
Chapter 2:
Psychrometry and Air-Conditioning
Dr. Eng. Sameh Shaaban
5 December 2009
Slide Nr. 13 of 13 SlidesThu 8:46:56 AM
Chapter 2:
Psychrometry and Air-Conditioning
Dr. Eng. Sameh Shaaban
5 December 2009