2. Thermal Environments
severe heat and hot:
vasodilation and sweating.
MODERATE
cold and severe cold:
Vasoconstriction and shivering.
3. Moderate Environment
It Requires a moderate degree of temperature controlIt Requires a moderate degree of temperature control
and easy operation condition omeotermia
It is characterized by:
• a level playing field in space and time
• no heat exchanges located
• low physical activity• low physical activity
• uniformity of clothing worn by subjects
4. Environment Moderate: RULES
ISO 7730-2006: Moderate Thermal Environments –
Determination of the PMV and PPD Indices andDetermination of the PMV and PPD Indices and
Specification of the Conditions for Thermal Comfort
ISO 7726: Ergonomics of the thermal environment –
Instruments and methods for measuring physicalInstruments and methods for measuring physical
quantities.
5. Moderate Environment
D.Lgs. N. 81 dtd April 9th 2008
Art. 181 comma 1: As part of its assessment under Art.Art. 181 comma 1: As part of its assessment under Art.
28, the employer shall assess all the risks related to
exposure to physical agents in order to identify and
adopt appropriate measures for prevention and
protection with special reference to good technical
standards (UNI, ISO) and good practice (Article 2
paragraph 1 part V: organizational and proceduralparagraph 1 part V: organizational and procedural
solutions consistent with existing legislation and the
rules of good practice, adopted voluntarily and aimed
at promoting the health and safety at work)
6. Microclimatic index
Tools that easily interpret a complex situation
Index related to the thermal situation of the humanIndex related to the thermal situation of the human
body temperature in relation to the post in place to
provide balance
Index related to the thermal sensation of heat or
cold sensation perceived by the human body orcold sensation perceived by the human body or
part of it
7. Thermal Comfort
That state of mind which expresses satisfaction
with the thermal environment. ISO 7730with the thermal environment. ISO 7730
Many complaints about the quality of an
environment are originated in the confined
thermal discomfort
Even where there are no health risks, can
that there was a thermal discomfortthat there was a thermal discomfort
8. Thermal Comfort
determined by the physical and psychological
comfort of the person who lives in a confinedcomfort of the person who lives in a confined
environment and is given a sense given by
different environmental conditions:
temperature
humidity
air speedair speed
light, noise
9. Heat balance
The human body is a substance capable of producing
thermal energy from and exchange with the
external environment through different processes,
which tend to maintain the internal temperature at
about 37 ° C (= S)
10. Heat balance
If S = 0 BALANCE (conditions omeoterme)
If S <0 HEAT LOSS
If S> 0 ACCUMULATION OF HEAT
11. Heat balance
M + W + C + R + K + Cres + Eres + E = S
M: metabolic expenditureM: metabolic expenditure
W: mechanical energy
C: convection with ambient air
R: radiation to / from the bodies in a environment
K: runK: run
Cres: breath (temperature)
Eres: breath (humidity)
E: evaporation, sweating and perspiration
12. Heat balance
How we adjust the temperature of the body
(physiology and behavior)(physiology and behavior)
The core temperature stays at about 36.7/37 ° C. If
the body is too hot: vasodilation, sweating,
pulmonary ventilation. Fan, light clothing.
If the body is too cold: vasoconstriction and
shivering. Movement, warm clothes...shivering. Movement, warm clothes...
13. Heat balance
Physiological monitoring system
There are "sensors" for the heat in the hypothalamusThere are "sensors" for the heat in the hypothalamus
the cold front and in rear
Equilibrium is reached when the signals of the two
ends are equal
14. Heat balance
Parameters that affect heat balance
metabolism (Met value)
clothing (Clo value)
different types of temperature (operating, mean
radiant, ...), different vertical temperature
humidityhumidity
air changes
drafts
Radiant asymmetry
15. Heat balance
M - metabolic expenditure
The amount of energy released by the metabolismThe amount of energy released by the metabolism
depends on the amount of physical activity. Normally,
the muscle activity is converted into heat for the body,
during a heavy physical work that may exceed 75%.
Metabolism is measured in Met (1 Met = 58.15 W/m2
of body surface area). An average adult has a surfaceof body surface area). An average adult has a surface
area of 1.7 m2 and a person in thermal comfort level
with an activity of a Met in a loss of about 58.15 * 1.7
= about 100 W.
16. Heat balance
metabolic expenditure– ISO 7730
Activity W/m2 MET
Lying 46 0.8
Relaxed, sitting 58 1.0
Relaxed, standing 70 1.2
Office 70 1.2
Housework 93 1.6Housework 93 1.6
Medium activity 116 2.0
Heavy activity 165 2.8
17. Heat balance
Calculating the value CLO
The clothing reduces heat loss due to isolationThe clothing reduces heat loss due to isolation
Unit used to measure the insulation is: CLO
1 CLO = 0.155 m2 ° C / W
a naked person has a CLO value = 0
a person with normal clothes CLO office has a value
= 1.0= 1.0
18. Heat balance
CLO - Thermal insulation
Clothes Index CLO
Shorts 0.1
Clothes typical tropical 0.3
Typical summer clothing 0.5
Clothing for light work 0.7Clothing for light work 0.7
Winter clothes (inside) 1.0
Winter clothes (external) 1.5
19. Heat balance
The methode PMV – PPD ISO 7730
“Moderate thermal environments – Determination“Moderate thermal environments – Determination
of the PMV & PPD index and specification of the
conditions of the thermal comfort”
EVALUATION OF THE LEVEL OF WELLNESS:
determined by local phenomenadetermined by local phenomena
(determined by the transient time)
total body heat
20. Heat balance Index PMV
Predicted Mean Vote (PMV), proposed by Fanger, is
defined on the ASHRAE 7-point bipolar scale shown
and is based on two assumptions by analyzing theand is based on two assumptions by analyzing the
experiences of a sample of individuals:
+3 hot
+2 warm
+1 light warm
0 neutral0 neutral
-1 light cool
-2 cool
-3 very cold
21. Heat balance Index PMV
PMV is calculated on the basis of:
environmental parameters: air temperature, mean
radiant temperature, air velocity, relative humidity;
level of activity for the metabolic expenditure;
restistence heat and evaporation of conductive
clothing
22. Heat balance Index PPD
The PPD index (expected percentage of dissatisfied)
is the expected percentage of dissatisfied PMV-
related, resulting in this diagram:related, resulting in this diagram:
23. Heat balance Index PPD
It shows that the percentage of dissatisfied (PPD) is
equal to 5% for PMV equal to 0, becomes the 10%equal to 5% for PMV equal to 0, becomes the 10%
limits of the range of well-being (-0.50 +0.50) and
is growing rapidly expulsion PMV values of
comfort.
PMV = -0.5 ~ +0.5
PPD < 10 %PPD < 10 %
24. Heat balance Index
Overall evaluation of thermal comfort
Experimental measurements
Estimated PMV
Assessment of the situation
25. Heat balance
The evaluation of thermal comfort is characterized
by measurement of:by measurement of:
• air temperature (ta)
• relative humidity (rh)
• mean radiant temperature (tr)
• air velocity (va)• air velocity (va)
26. Heat balance
Comfort determined by local phenomena
Air flow: temperature, speed and air turbulence
Radiant asymmetry: asymmetry plane radiantRadiant asymmetry: asymmetry plane radiant
temperature
VERTICAL GRADIENT OF
TEMPERATURE: The values of air
temperature at a height of head and ankles
shareshare
TEMPERATURE OF THE FLOOR: Floor
temperature
27. Measurement instruments
HD32.1
Inputs: 8 SICRAM with auto-Inputs: 8 SICRAM with auto-
recognition of the probes
Serial Port RS232
USB serial port
Keyboard and LCD display
Internal battery or power
200 hours autonomy200 hours autonomy
Data Storage
29. Measurement instruments
Globethermometer TP3275
In accordance to the standard ISO7726In accordance to the standard ISO7726
Radiant temperature measuredtg [-30 + 120°C]
Used for the calculation of mean radiant
temperature tr
30. Measurement instruments
Temperature and relative humidity HP3217R
Sensor Pt100 for temperature (-30 … +100°C)
Sensor capacitive for relative humidity (5...98 % UR)
31. Measurement instruments
Mean radiant temperature, tr
Average temperature of the surfaces that enclose theAverage temperature of the surfaces that enclose the
environment, or better than all the elements that
surround us and are at a different temperature than the
body. For a standard black globe thermometer:tr =
[(tg +273)4 + 2.5 x 108 x va0.6(tg – ta)]1/4 – 273
tg = globe temperature,tg = globe temperature,
ta = air temperature,
va = air velocity at the level of globe
32. Order codes
Moderate Environmental ( ISO7730/2006)Moderate Environmental ( ISO7730/2006)
HD32.1 (basic deltaLog10 is included)
+ probes ( HP3217R + AP3203 + TP3275 or TP3276)
33. Orders codes
Hot Environmental ( ISO7243:WBGT)
HD32.1 (basic deltaLog10 is included)
+ MC1 unlock software in deltaLog10
+ probes ( HP3217R or TP3207 +HP3201 ++ probes ( HP3217R or TP3207 +HP3201 +
TP3275 or TP3276)
34. Order codes
Hot Environmental ( ISO7933:PHS)
HD32.1 (basic deltaLog10 is included)
+ MC1 unlock software in deltaLog10
+ probes ( HP3217R + AP3203 + TP3275 or+ probes ( HP3217R + AP3203 + TP3275 or
TP3276)
36. Order codes
Local Discomfort (ISO7730/2006)
HD32.1 (basic deltaLog10 is included)
+ MC3 unlock software in deltaLog10
+ MC4 unlock firmware B in the instruments
+ probes ( TP3227K two probes Head and Body+ probes ( TP3227K two probes Head and Body
in one SICRAM connector module + TP3227PC
two probes Ankle and Floor in one SICRAM
connector module + TP3207R radiant probe)
37. Measurement instruments
CO / CO2 /Lights (ANSI/ASHRAE Standard
62.1-2004)62.1-2004)
HD32.1 (basic deltaLog10 is included)
+ MC5 unlock software in deltaLog10 + probes
38. Measurement instruments
HD32.2 (basic deltaLog10 is included)
+ probes ( TP3207.2 + TP3276.2 + HP3201.2)+ probes ( TP3207.2 + TP3276.2 + HP3201.2)
Only for Hot environmental (only
WBGT), NOT for Moderate, Cold
environmental and Discomfort analysis.
39. Measurement instruments
HD32.3 (basic deltaLog10 is included)
+ probes ( TP3217.2 + AP3203.2 + TP3276.2 ++ probes ( TP3217.2 + AP3203.2 + TP3276.2 +
HP3201.2)
Only for Hot environmental (only WBGT)
and Moderate ( PMV and PPD) , NOT for
Cold and not for Discomfort analysis.
40. Reference Standards
ISO7726 Ergonomics of the thermal environment – Instruments for measuring physical
quantities
ISO8896 Ergonomics of the thermal environment – Determination of metabolic rateISO8896 Ergonomics of the thermal environment – Determination of metabolic rate
ISO7933 Ergonomics of the thermal environment – Analytical determination and
interpretation of heat stress using calculation of the predicted heat strain
ISO7243 Estimation of the heat stress on working man, based on the WBGT-index (wet
bulb globe temperature)
ISO7730 Ergonomics of the thermal environment – Analytical determination and
interpretation of thermal comfort using calculation of the PMV and PPD indices
and local thermal comfort criteriaand local thermal comfort criteria
ISO11079 Ergonomics of the thermal environment – Determination and interpretation of
cold stress when using required clothing insulation (IREQ) and local cooling effects
ISO9920 Ergonomics of the thermal environment – Estimation of thermal insulation and
water vapour resistance of a clothing ensemble
ANSI/ASHRAE Standard 55-2010 Thermal Environmental Conditions for Human
Occupancy