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Microclima eng

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Microclima eng

  1. 1. Analysis and measurement ofAnalysis and measurement of microclimate in the workplace
  2. 2. Thermal Environments severe heat and hot: vasodilation and sweating. MODERATE cold and severe cold: Vasoconstriction and shivering.
  3. 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. 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. 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. 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. 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. 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. 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. 10. Heat balance If S = 0 BALANCE (conditions omeoterme) If S <0 HEAT LOSS If S> 0 ACCUMULATION OF HEAT
  11. 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. 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. 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. 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. 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. 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. 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. 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. 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. 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. 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. 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. 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. 24. Heat balance Index Overall evaluation of thermal comfort Experimental measurements Estimated PMV Assessment of the situation
  25. 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. 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. 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
  28. 28. Measurement instruments Hot-wire anemometerAP3203 / AP3203-F In accordance with standardISO 7726In accordance with standardISO 7726 Sensor type: NTC 10kOhm Measure uncertainty: ± 0.02 m/s (0.05÷1 m/s) ± 0.1 m/s (1÷5 m/s) Measure field: 0.05 … 5m/s 0°C … +80°C (per AP3203) / -30°C … +30°C (for AP3203-F)AP3203) / -30°C … +30°C (for AP3203-F) Connextions: 7 wires + module SICRAM Connector: 8 female poles DIN45326
  29. 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. 30. Measurement instruments Temperature and relative humidity HP3217R Sensor Pt100 for temperature (-30 … +100°C) Sensor capacitive for relative humidity (5...98 % UR)
  31. 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. 32. Order codes Moderate Environmental ( ISO7730/2006)Moderate Environmental ( ISO7730/2006) HD32.1 (basic deltaLog10 is included) + probes ( HP3217R + AP3203 + TP3275 or TP3276)
  33. 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. 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)
  35. 35. Order codes Cold Environmental ( ISO11079) HD32.1 (basic deltaLog10 is included) + MC2 unlock software in deltaLog10 + probes ( HP3217R + AP3203F + TP3275)+ probes ( HP3217R + AP3203F + TP3275)
  36. 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. 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. 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. 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. 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

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