TESTO 400 - Page 54

9 Operation
54
Clothing
Clothing reduces body heat losses and is therefore classified based on its
insulating value. The insulating effect of clothing is given in the unit clo or m²
K/W (1 clo = 0.155 m² K/W). The clo value can be calculated by adding together
the values of the individual items of clothing. Insulating values for individual
items of clothing can be found in ISO 7730. Alternatively, a range can be
selected.
Parameter in clo Parameter in m
2
K/W
Description
0 to 0.02
No clothing
0.03 to 0.29
0.005 to 0.045
Underwear
0.30 to 0.49
0.046 to 0.077
Shorts and T-shirt
0.50 to 0.79
0.078 to 0.122
Trousers and T-shirt
0.80 to 1.29
0.123 to 0.200
Light business wear
1.30 to 1.79
0.201 to 0.277
Warm business wear
1.80 to 2.29
0.278 to 0.355
Jacket or coat
2.30 to 2.79
0.356 to 0.432
Warm winter clothing
2.80 to 3.00
0.433 to 0.465
Extremely warm winter clothing
Activity
The metabolic rate specifies the energy released by oxidation processes in the
human body, and depends on muscle activity. The metabolic rate is given in met
or W/m
2
(1 met = 58.2 W/m² body surface area). The average adult has a body
surface area of 1.7 m². In a state of thermal comfort, a person with a metabolic
rate of 1 met has heat loss of approx. 100 W. When calculating the metabolic
rate, a mean value of the activity of the relevant person within the past hour
must be used. Met values for various activities can also be found in ISO 7730.
Parameter in
met
Parameter in
W/m
2
Description
0.1 to 0.7
6 to 45
Lying down, relaxed
0.8 to 0.9
46 to 57
Sitting down, relaxed
1.0 to 1.1
58 to 59
Seated activity
1.2 to 1.5
70 to 92
Standing
1.6 to 1.7
93 to 104
Standing up, light activity
1.8 to 1.9
105 to 115
Standing up, moderate activity
2.0 to 2.3
116 to 139
Slow walking
2.4 to 2.9
140 to 174
Quick walking
3.0 to 3.4
175 to 203
Strenuous activity
3.5 to 4.0
204 - 233
Extremely strenuous activity