dusan fiala
DESCRIPTION
thermal Comfort, fiala model, CFDTRANSCRIPT
Detailed multi-node model of human physiology to predict dynamic thermal comfort responses
Dusan FIALA, PhD IBBTEUniversity of StuttgartGermany
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� Model Systems
� Validation examples
� Physiological modelling of thermal comfort
Contents
Dusan Fiala18.11.2008
CIBSE Seminar - Thermal Comfort for Building Occupants · Cibse Natural Ventilation Group
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Model of human thermoregulation: Passive System
Dusan Fiala18.11.2008
CIBSE Seminar - Thermal Comfort for Building Occupants · Cibse Natural Ventilation Group
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Model of human thermoregulation: Active System
Dusan Fiala18.11.2008
CIBSE Seminar - Thermal Comfort for Building Occupants · Cibse Natural Ventilation Group
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Active System: System coefficients
-10 -8 -6 -4 -2 0 2 40.0
0.5
1.0
1.5
2.0
2.5
[K]
coef
ficie
nt
Regression
bsw
,sk
∆Tsk,m,t
bsw,sk
[g m
in K
]
-1-1
-8 -6 -4 -2 0 2 4
-10
0
10
20
30
40
50
[K]
coef
ficie
nt
[W
K ²
]
Regression bdl,sk
∆Tsk,m,t
b dl,s
k-
-14 -12 -10 -8 -6 -4 -2-25
-20
-15
-10
-5
0
[K]
coef
ficie
nt
[W K
]
Regression bsh,sk
∆Tsk,m,t
bsh
,sk
-1
Dusan Fiala18.11.2008
CIBSE Seminar - Thermal Comfort for Building Occupants · Cibse Natural Ventilation Group
-1 -0.5 0 0.5 1 1.5 20
2
4
6
8
10
12
14
[K]
coef
ficie
nt
Regression
∆Thy,t
bsw
,hy
bsw,hy
[g m
in K
]
-1-1
-0.5 0 0.5 1 1.5
10
20
30
40
50
60
70
80
[K]
coef
ficie
nt
[W
K ²
]
Regression
b dl,h
y
bdl,hy
∆Thy,t
-
-12 -10 -8 -6 -4 -2 0 2
-80
-60
-40
-20
0
[K]
coef
ficie
nt
[
K
]
Regression
∆Tsk,m,t
bcs,sk
b cs,
sk-1
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Transient conditions
33
34
35
36
37
mea
n sk
in te
mp.
[°C
]
Ta=Tw=48°C28°C 28°C
37
38
rect
al te
mpe
ratu
re [°
C]
28
30
32
34
36
mea
n sk
in te
mp.
[°C
]
36.5
37.0
37.5
rect
al te
mp.
[°C
]
150
200
evap
orat
ion
[W]
Ta=17°C
Ta=43°C Ta=43°C
Dusan Fiala18.11.2008
CIBSE Seminar - Thermal Comfort for Building Occupants · Cibse Natural Ventilation Group
Ta=Tw, va<0.1m/s, rh=30%, Icl=0.1clo, act=1met, n=3
0 30 60 90 120 150 180 210 2400
50
100
150
200
250
300
time [min]
evap
. hea
t los
s [W
]
experiment simulation
36 rect
al te
mpe
ratu
re [°
C]
28
Ta=Tw, va=0.1m/s, rh=30%, Icl=0.1clo, act=1met, n=3
0 30 60 90 120 150 180 210 240
100
150
200
time [min]
met
abol
ism
[W
]
experiment simulation Stolwijk model
0
50
100
150
evap
orat
ion
[W]
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Validation: Principal human thermal behaviour
22
24
26
28
30
32
34
36m
ean
skin
tem
p. [°
C]
38
rect
al te
mp.
[°C
]
28
30
32
34
36
38
mea
n sk
in te
mp.
[°C
]
37
38
rect
al T
[°C
]
Dusan Fiala18.11.2008
CIBSE Seminar - Thermal Comfort for Building Occupants · Cibse Natural Ventilation Group
36
37
rect
al te
mp.
[°C
]
t=60min, Tw=Ta, va=0.3m/s, rh=50%, act=0.8met, Icl=0.1clo, n=44
5 10 15 20 27
100
200
300
ambient temperature [°C]
met
abol
ism
[W
]
experiment: mean ± SD simulationt=60min, Tw=Ta, va=0.1m/s, rh=30%, Icl=0.1clo, act=1met, n=3
20 24 28 32 36 40 44 48
20
40
60
80
100
120
140
ambient temperature [°C]
evap
orat
ion
[W/m
²]
experiment : mean ± SD simulation
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Radiant Temperature Asymmetry
35
40
Tem
pera
ture
[°C
]
Neck PosForeheadFoot instepLeg LowPost
Dusan Fiala18.11.2008
CIBSE Seminar - Thermal Comfort for Building Occupants · Cibse Natural Ventilation Group
20
25
30
0 5 10 15 20 25
Radiant temperature asymmetry [K]
Tem
pera
ture
[°C
]
Leg LowPostMean Skin TempRectal TempMean Rad TempAir TempSim.
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Field measurements ´Hiking´: Boundary conditions
0.0
2.0
4.0
6.0
8.0
10.0
12.0
0 30 60 90 120 150 180
Time [min]
air
tem
pera
ture
[°C
]
Simulation
Experiment
0.6
0.8
1.0
1.2
1.4
0 30 60 90 120 150 180
Time [min]
air
spee
d [m
/s]
Sim. 1
Experiment
Air temperatureAir temperatureAir temperatureAir temperature Wind speedWind speedWind speedWind speed
Dusan Fiala18.11.2008
CIBSE Seminar - Thermal Comfort for Building Occupants · Cibse Natural Ventilation Group
0
10
20
30
40
50
60
70
80
90
0 30 60 90 120 150 180
Time [min]
Sol
ar R
adia
tion
[W/m
2]
Sim. 1
Experiment
0
100
200
300
400
500
600
700
0 30 60 90 120 150 180
Time [min]
Qm
et [W
]
Simulation
Experiment
Solar RadiationSolar RadiationSolar RadiationSolar Radiation Activity / Metabolic rateActivity / Metabolic rateActivity / Metabolic rateActivity / Metabolic rate
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Field measurements ´Hiking´: Body temperatures
26
28
30
32
34
36
38
40
0 30 60 90 120 150 180
Time [min]
Tsk
m [
oC
] Sim. 1
Sim. 2
Sim. 3
Experiment
35
36
37
38
39
40
0 30 60 90 120 150 180
Time [min]
Tre
ctal
[oC
] Sim. 1
Sim. 2
Sim. 3
Experiment
Mean skin temperatureMean skin temperatureMean skin temperatureMean skin temperature Body core temperatureBody core temperatureBody core temperatureBody core temperature
Dusan Fiala18.11.2008
CIBSE Seminar - Thermal Comfort for Building Occupants · Cibse Natural Ventilation Group
28
30
32
34
36
38
40
0 30 60 90 120 150 180
Time [min]
Tsk
, bac
k [
oC
]
Sim. 1
Sim. 2
Sim. 3
Experiment
26
28
30
32
34
36
38
40
0 30 60 90 120 150 180
Time [min]
Tsk
, che
st [
oC
]
Sim. 1
Experiment
Skin temperature: ChestSkin temperature: ChestSkin temperature: ChestSkin temperature: Chest Skin temperature: BackSkin temperature: BackSkin temperature: BackSkin temperature: Back
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Field measurements ´Hiking´: Skin temperatures
24
26
28
30
32
34
36
38
40
0 30 60 90 120 150 180
Time [min]
Tsk
, for
earm
[oC
]
Sim. 1
Sim. 2
Sim. 3
Experiment
20
22
24
26
28
30
32
34
36
38
40
0 30 60 90 120 150 180
Time [min]
Tsk
, arm
[oC
]
Sim. 1
Sim. 2
Sim. 3
Experiment
Skin temperature: Upper armSkin temperature: Upper armSkin temperature: Upper armSkin temperature: Upper armSkin temperature: Lower armSkin temperature: Lower armSkin temperature: Lower armSkin temperature: Lower arm
Dusan Fiala18.11.2008
CIBSE Seminar - Thermal Comfort for Building Occupants · Cibse Natural Ventilation Group
20
22
24
26
28
30
32
34
36
38
40
0 30 60 90 120 150 180
Time [min]
Tsk
, cal
f [oC
]
Sim. 1
Sim. 2
Sim. 3
Experiment
24
26
28
30
32
34
36
38
40
0 30 60 90 120 150 180
Time [min]
Tsk
, leg
[oC
]
Sim. 1
Sim. 2
Sim. 3
Experiment
Skin temperature: Upper LegSkin temperature: Upper LegSkin temperature: Upper LegSkin temperature: Upper LegSkin temperature: Lower legSkin temperature: Lower legSkin temperature: Lower legSkin temperature: Lower leg
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Field measurements ´Hiking´ (Test VI)
-2.0
0.0
2.0
4.0
6.0
8.0
10.0
12.0
0 30 60 90 120 150 180
Time [min]
air
tem
pera
ture
[°C
]
Sim. 1
Experiment
0
50
100
150
200
250
300
350
0 30 60 90 120 150 180
Time [min]
Sol
ar R
adia
tion
[W/m
2]
Sim. 1
Experiment
Air temperatureAir temperatureAir temperatureAir temperature Solar RadiationSolar RadiationSolar RadiationSolar Radiation
Dusan Fiala18.11.2008
CIBSE Seminar - Thermal Comfort for Building Occupants · Cibse Natural Ventilation Group
26
28
30
32
34
36
38
40
0 30 60 90 120 150 180
Time [min]
Tsk
m [
oC
] Sim. 1
Sim. 2
Sim. 3
Experiment
26
28
30
32
34
36
38
40
0 30 60 90 120 150 180
Time [min]
Tsk
, che
st [
oC
]
Sim. 1
Sim. 2
Sim. 3
Experiment
Mean skin temperatureMean skin temperatureMean skin temperatureMean skin temperatureSkin temperature: ChestSkin temperature: ChestSkin temperature: ChestSkin temperature: Chest
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Thermal Comfort: modelling approaches
� Existing models� Nevins et al.: TS = f (To,rh) � Fanger Model (iso7730): TS = f (∆Q), i.e.heat flux� Gagge Model: TS = f (Ta,pa)
f (wsk)� Nishi et al Model: TS = f (Tsk)� Aser & Hsu Model: TS = f (KS)
} Physilogical
approach
Dusan Fiala18.11.2008
CIBSE Seminar - Thermal Comfort for Building Occupants · Cibse Natural Ventilation Group
� Aser & Hsu Model: TS = f (KS)
� …
� Question: What physiological parameters do actually govern the human Thermal Sensation?
} approach
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Simulation and analysis of TC experiments
-2 -1 0 1 2 3 4 5 6
msw [g/min]
-3
-2
-1
0
1
2
3
The
rmal
Sen
satio
n
TSV = f (Sw)
-20 0 20 40 60 80
Qsk - Qsk,0 [W]
-3
-2
-1
0
1
2
3
The
rmal
Sen
satio
n
TSV = f (Qsk)
Dusan Fiala18.11.2008
CIBSE Seminar - Thermal Comfort for Building Occupants · Cibse Natural Ventilation Group
msw [g/min] Qsk - Qsk,0 [W]
-0.6 -0.4 -0.2 0 0.2 0.4
Thy - Thy,0 [K]
-3
-2
-1
0
1
2
3
The
rmal
Sen
satio
n
TSV = f (Thy)
-5 -4 -3 -2 -1 0 1 2 3
Tsk,m - Tsk,m,0 [K]
-3
-2
-1
0
1
2
3
The
rmal
Sen
satio
n
TS = f (Tsk)
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Effect of body core temperature (exercising subjects)
φ = gsk x ghy
3
4
5
6
gsk
[ ]
1.0
1.5
ghy
[ ]
Dusan Fiala18.11.2008
-10 -8 -6 -4 -2 0 2
Tsk,m - Tsk,m,0 [K]
0
1
2
3
gsk
[ ]
-0.5 0.0 0.5 1.0 1.5 2.0
Thy - Thy,0 [K]
0.0
0.5ghy
[ ]
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Dynamic components of Thermal Sensation
-1
0
1
2
The
rmal
Sen
satio
n
dT dTsk,m f ( )
Ta=28°C Ta=18°C Ta=28°C
(64.4°F) (82.4°F)(82.4°F)
→ Dynamic Thermal Senstation (DTS)
Dusan Fiala18.11.2008
CIBSE Seminar - Thermal Comfort for Building Occupants · Cibse Natural Ventilation Group
0 30 60 90 120 150 180 210 240
-3
-2
-1
time [min]
The
rmal
Sen
satio
n
experiment static TS dynamic TS (DTS)
-dTsk,m
dtf ( ) +
dTsk,m
dt f ( )
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Validation examples: Ramps
-1
0
1
2
3
The
rmal
Sen
satio
n [
]
27
28
29
30
31
Air
tem
pera
ture
Ta
[°C
]
Dusan Fiala18.11.2008
CIBSE Seminar - Thermal Comfort for Building Occupants · Cibse Natural Ventilation Group
0 30 60 90 120 150 180 210 240
time [min]
-3
-2
-1
The
rmal
Sen
satio
n [
]
25
26
27
Air
tem
pera
ture
Ta
[°C
]
experiment DTS (Ta)
Tw=Ta va=0.1m/s Tdew=12°C Icl=0.5clo act=1.2met n=12
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Validation examples: Step changes in Ta
-1
0
1
2
3
The
rmal
Sen
satio
n [
]
Dusan Fiala18.11.2008
CIBSE Seminar - Thermal Comfort for Building Occupants · Cibse Natural Ventilation Group
0 30 60 90 120 150 180-3
-2
time [min]
The
rmal
Sen
satio
n [
]
exp.: To = 27/22°C (sW/N) exp.: To = 21/17°C (N/s C)
DTS: To = 27/22°C DTS: To = 21/17°C
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Validation examples: Transient exercise
0
1
2
3
2
3
The
rmal
Sen
satio
n
activ
ity le
vel
[met
]
experiment
simulation
(activity)
Dusan Fiala18.11.2008
CIBSE Seminar - Thermal Comfort for Building Occupants · Cibse Natural Ventilation Group
Ta =Tw =10°C va = 0.1m/s rh = 52% Icl=1.2clo n =10
0 15 30 45 60 75 90 105 120-3
-2
-1
1
time [min]
The
rmal
Sen
satio
n
activ
ity le
vel
[met
]
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Validation examples: Periodic changes
-1
0
1
2
3
24
26
28
30
The
rmal
Sen
satio
n [
]
Air
tem
pera
ture
Ta
[°C
]
Dusan Fiala18.11.2008
CIBSE Seminar - Thermal Comfort for Building Occupants · Cibse Natural Ventilation Group
Tw=Ta va=0.25m/s rh=50% Icl=0.7clo n=11
0 15 30 45 60 75 90 105 120-3
-2
20
22
time [min]
The
rmal
Sen
satio
n [
]
Air
tem
pera
ture
Ta
[°C
]
exp.: males exp.: female DTS (Ta)