Cooling and Heating Load Estimation：加热和冷却负载的估计-98页精选文档
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triple glazing
1/4 in. [6.4 mm] air spaces 1/2 in. [12.8 mm] air spaces 1/4 in. [6.4 mm] argon spaces 1/2 in. [12.8 mm] argon spaces
fixed frames, vertical installation
people
lights
equipment/appliances
infiltration
ventilation
system heat gains
© American Standard Inc. 2000
space coil load load
Air Conditioning Clinic TRG-TRC002-EN
Qwall = 0.06 380 22 = 502 Btu/hr Qroof = 0.057 2,700 80 = 12,312 Btu/hr
[ Qwall = 0.33 36.3 12 = 144 W ] [ Qroof = 0.323 250.7 44 = 3,563 W ]
0.4%
DB WB
95°F 76°F [35°C] [25°C]
1%
DB WB
93°F 75°F [34°C] [24°C]
2%
DB WB
90°F 74°F [32°C] [23°C]
© American Standard Inc. 2000
Air Conditioning Clinic TRG-TRC002-EN
Heat always flows from a higher temperature substance to a lower temperature substance
Heat can be transferred from one substance to another
© American Standard Inc. 2000
Heat Conduction through Surfaces
© American Standard Inc. 2000
Air Conditioning Clinic TRG-TRC002-EN
Conduction through a Shaded Wall
Q = U A T
© American Standard Inc. 2000
Factors Affecting Human Comfort
Dry-bulb temperature Humidity Air movement Fresh air Clean air Noise level Adequate lighting Proper furniture and
North
Room 101 Room 102
plan view
© American Standard Inc. 2000
elevation view (Room 101)
Air Conditioning Clinic TRG-TRC002-EN
Outdoor Design Conditions
St. Louis, Missouri
aluminum without aluminum with thermal break thermal break
© American Standard Inc. 2000
Air Conditioning Clinic TRG-TRC002-EN
Surrounding Air Conditions
© American Standard Inc. 2000
Air Conditioning Clinic TRG-TRC002-EN
work surfaces
© American Standard Inc. 2000
Air Conditioning Clinic TRG-TRC002-EN
Indoor Design Conditions
humidity ratio
© American Standard Inc. 2000
A
comfort zone
Conduction through a Shaded Wall
Qwall = 0.06 380 (95 – 78) = 388 Btu/hr
[ Qwall = 0.33 36.3 (35 – 25.6) = 113 W ]
© American Standard Inc. 2000
60°F
[15.6°C]
sensible heat
212°F
[100°C]
© American Standard Inc. 2000
212°F
[100°C]
latent heat
212°F
[100°C]
Air Conditioning Clinic TRG-TRC002-EN
Heat Generated by People
CLTD 19 17 14 12 9 8 6 4 4 3 3 4 4 6 7 9 12 17 21 24 27 27 25 23 (°C)
© American Standard Inc. 2000
Air Conditioning Clinic TRG-TRC002-EN
Conduction through Sunlit Surfaces
70°F
[21.2°C]
80°F
[26.7°C]
dry-bulb temperature
Air Conditioning Clinic TRG-TRC002-EN
Cooling and Heating Load Estimation
period two
Cooling Load Estimation
Measuring Heat Quantity
1 lb
water
1 Btu
60°F
61°F
1 kg water
© American Standard Inc. 2000
15°C
1 kcal
[4.19 kJ]
16°C
Air Conditioning Clinic TRG-TRC002-EN
Sensible versus Latent Heat
Air Conditioning Clinic TRG-TRC002-EN
Methods of Heat Transfer
convection
warm air
radiation
hot water
© American Standard Inc. 2000
conduction
cool air
Air Conditioning Clinic TRG-TRC002-EN
Air Conditioning Clinic TRG-TRC002-EN
Sunlit Surfaces
sun rays
solar angle changes throughout the day
© American Standard Inc. 2000
Air Conditioning Clinic TRG-TRC002-EN
Rindoor-air film 0.68 [0.12]
]
R total
16.99 [2.99]
1 U=
Rtotal U = 0.06 Btu/hr•ft2•°F
[ U = 0.33 W/m2•°K ]
© American Standard Inc. 2000
Air Conditioning Clinic TRG-TRC002-EN
period one
Human Comfort
© American Standard Inc. 2000
Air Conditioning Clinic TRG-TRC002-EN
Principles of Heat Transfer
Heat energy cannot be destroyed
Time Lag
A
time lag B
solar effect
12
mid
© American Standard Inc. 2000
6
a.m.
12
noon
6
p.m.
12
mid
Air Conditioning Clinic TRG-TRC002-EN
Conduction through Sunlit Surfaces
© American Standard Inc. 2000
Air Conditioning Clinic TRG-TRC002-EN
U-factors for Windows
single glazing
1/8 in. [3.2 mm] glass
double glazing
1/4 in. [6.4 mm] air space 1/2 in. [12.8 mm] air space 1/4 in. [6.4 mm] argon space 1/2 in. [12.8 mm] argon space
Air Conditioning Clinic TRG-TRC002-EN
U-factor
concrete block aluminum siding
© American Standard Inc. 2000
wood studs insulation gypsum board
Air Conditioning Clinic TRG-TRC002-EN
© American Standard Inc. 2000
Air Conditioning Clinic TRG-TRC002-EN
Cooling Load Components
roof
glass solar
glass conduction
exterior wall
© American Standard Inc. 2000
conduction through roof, walls, windows, and skylights
solar radiation through windows, skylights
conduction through ceiling, interior partition walls, and floor
Cooling and Heating Load Estimation A Trane Air Conditioning Clinic
© American Standard Inc. 2000
Air Conditioning Clinic TRG-TRC002-EN
Cooling and Heating Load Estimation
Time of Peak Cooling Load
east-facing
mid
© American Standard Inc. 2000
6
a.m.
12
noon
6
p.m.
12
mid
Air Conditioning Clinic TRG-TRC002-EN
Example Office Space (Room 101)
people infiltration
lights equipment
floor
partition wall
Air Conditioning Clinic TRG-TRC002-EN
Cooling Load Components
cooling load components
sensible latent load load
U-factor for Example Wall
thermal resistance (R)
Routdoor-air film 0.25 [0.04]
Rsiding
0.61 [0.11]
Rconcrete block 2.00 [0.35]
Rinsulation 13.00 [2.29]
Rgypsum board 0.45 [0.08]
Q = U A CLTD
© American Standard Inc. 2000
Air Conditioning Clinic TRG-TRC002-EN
CLTD Factors for West-Facing Wall
hour 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 CLTD 35 30 25 21 17 14 11 8 7 6 6 7 8 10 12 16 22 30 37 44 48 48 45 41 (°F)
1/4 in. [6.4 mm] air spaces 1/2 in. [12.8 mm] air spaces 1/4 in. [6.4 mm] argon spaces 1/2 in. [12.8 mm] argon spaces
fixed frames, vertical installation
people
lights
equipment/appliances
infiltration
ventilation
system heat gains
© American Standard Inc. 2000
space coil load load
Air Conditioning Clinic TRG-TRC002-EN
Qwall = 0.06 380 22 = 502 Btu/hr Qroof = 0.057 2,700 80 = 12,312 Btu/hr
[ Qwall = 0.33 36.3 12 = 144 W ] [ Qroof = 0.323 250.7 44 = 3,563 W ]
0.4%
DB WB
95°F 76°F [35°C] [25°C]
1%
DB WB
93°F 75°F [34°C] [24°C]
2%
DB WB
90°F 74°F [32°C] [23°C]
© American Standard Inc. 2000
Air Conditioning Clinic TRG-TRC002-EN
Heat always flows from a higher temperature substance to a lower temperature substance
Heat can be transferred from one substance to another
© American Standard Inc. 2000
Heat Conduction through Surfaces
© American Standard Inc. 2000
Air Conditioning Clinic TRG-TRC002-EN
Conduction through a Shaded Wall
Q = U A T
© American Standard Inc. 2000
Factors Affecting Human Comfort
Dry-bulb temperature Humidity Air movement Fresh air Clean air Noise level Adequate lighting Proper furniture and
North
Room 101 Room 102
plan view
© American Standard Inc. 2000
elevation view (Room 101)
Air Conditioning Clinic TRG-TRC002-EN
Outdoor Design Conditions
St. Louis, Missouri
aluminum without aluminum with thermal break thermal break
© American Standard Inc. 2000
Air Conditioning Clinic TRG-TRC002-EN
Surrounding Air Conditions
© American Standard Inc. 2000
Air Conditioning Clinic TRG-TRC002-EN
work surfaces
© American Standard Inc. 2000
Air Conditioning Clinic TRG-TRC002-EN
Indoor Design Conditions
humidity ratio
© American Standard Inc. 2000
A
comfort zone
Conduction through a Shaded Wall
Qwall = 0.06 380 (95 – 78) = 388 Btu/hr
[ Qwall = 0.33 36.3 (35 – 25.6) = 113 W ]
© American Standard Inc. 2000
60°F
[15.6°C]
sensible heat
212°F
[100°C]
© American Standard Inc. 2000
212°F
[100°C]
latent heat
212°F
[100°C]
Air Conditioning Clinic TRG-TRC002-EN
Heat Generated by People
CLTD 19 17 14 12 9 8 6 4 4 3 3 4 4 6 7 9 12 17 21 24 27 27 25 23 (°C)
© American Standard Inc. 2000
Air Conditioning Clinic TRG-TRC002-EN
Conduction through Sunlit Surfaces
70°F
[21.2°C]
80°F
[26.7°C]
dry-bulb temperature
Air Conditioning Clinic TRG-TRC002-EN
Cooling and Heating Load Estimation
period two
Cooling Load Estimation
Measuring Heat Quantity
1 lb
water
1 Btu
60°F
61°F
1 kg water
© American Standard Inc. 2000
15°C
1 kcal
[4.19 kJ]
16°C
Air Conditioning Clinic TRG-TRC002-EN
Sensible versus Latent Heat
Air Conditioning Clinic TRG-TRC002-EN
Methods of Heat Transfer
convection
warm air
radiation
hot water
© American Standard Inc. 2000
conduction
cool air
Air Conditioning Clinic TRG-TRC002-EN
Air Conditioning Clinic TRG-TRC002-EN
Sunlit Surfaces
sun rays
solar angle changes throughout the day
© American Standard Inc. 2000
Air Conditioning Clinic TRG-TRC002-EN
Rindoor-air film 0.68 [0.12]
]
R total
16.99 [2.99]
1 U=
Rtotal U = 0.06 Btu/hr•ft2•°F
[ U = 0.33 W/m2•°K ]
© American Standard Inc. 2000
Air Conditioning Clinic TRG-TRC002-EN
period one
Human Comfort
© American Standard Inc. 2000
Air Conditioning Clinic TRG-TRC002-EN
Principles of Heat Transfer
Heat energy cannot be destroyed
Time Lag
A
time lag B
solar effect
12
mid
© American Standard Inc. 2000
6
a.m.
12
noon
6
p.m.
12
mid
Air Conditioning Clinic TRG-TRC002-EN
Conduction through Sunlit Surfaces
© American Standard Inc. 2000
Air Conditioning Clinic TRG-TRC002-EN
U-factors for Windows
single glazing
1/8 in. [3.2 mm] glass
double glazing
1/4 in. [6.4 mm] air space 1/2 in. [12.8 mm] air space 1/4 in. [6.4 mm] argon space 1/2 in. [12.8 mm] argon space
Air Conditioning Clinic TRG-TRC002-EN
U-factor
concrete block aluminum siding
© American Standard Inc. 2000
wood studs insulation gypsum board
Air Conditioning Clinic TRG-TRC002-EN
© American Standard Inc. 2000
Air Conditioning Clinic TRG-TRC002-EN
Cooling Load Components
roof
glass solar
glass conduction
exterior wall
© American Standard Inc. 2000
conduction through roof, walls, windows, and skylights
solar radiation through windows, skylights
conduction through ceiling, interior partition walls, and floor
Cooling and Heating Load Estimation A Trane Air Conditioning Clinic
© American Standard Inc. 2000
Air Conditioning Clinic TRG-TRC002-EN
Cooling and Heating Load Estimation
Time of Peak Cooling Load
east-facing
mid
© American Standard Inc. 2000
6
a.m.
12
noon
6
p.m.
12
mid
Air Conditioning Clinic TRG-TRC002-EN
Example Office Space (Room 101)
people infiltration
lights equipment
floor
partition wall
Air Conditioning Clinic TRG-TRC002-EN
Cooling Load Components
cooling load components
sensible latent load load
U-factor for Example Wall
thermal resistance (R)
Routdoor-air film 0.25 [0.04]
Rsiding
0.61 [0.11]
Rconcrete block 2.00 [0.35]
Rinsulation 13.00 [2.29]
Rgypsum board 0.45 [0.08]
Q = U A CLTD
© American Standard Inc. 2000
Air Conditioning Clinic TRG-TRC002-EN
CLTD Factors for West-Facing Wall
hour 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 CLTD 35 30 25 21 17 14 11 8 7 6 6 7 8 10 12 16 22 30 37 44 48 48 45 41 (°F)