125 YMCB Microclimate and Architecture 2 Lecturetzb.fsv.cvut.cz/files/vyuka/125ymcb/prednasky/125ymcb-04.pdf · 2014-03-24 · 1 ČVUT v Praze Fakulta stavební Katedra technických

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ČVUT v PrazeFakulta stavební

Katedra technických zařízení budov

125 YMCBMicroclimate and Architecture

2nd Lecture

prof. Ing. Karel Kabele, CSc.

A227b

[email protected]

PROBLEMS RELATED TO INDOORENVIRONMENTAL QUALITY

125 YMCB 2013/014 prof.Karel Kabele 29

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Indoor Environment and Health

• Sick Building Syndrome (SBS)

– set of symptoms and problems associated with users stay in a building without a clear cause

Symptoms

– Complaints of discomfort, irritation of eyes, nose, headaches, fatigue, difficulty in concentrating;

– The cause is not known;

– Most problems disappear after leaving the building.


Building Related Illness (BRI)

– Diagnosed disease associated with stay in a building with a clear cause: occurrence of mold, gases concentration, …

Symptoms

– Users complain about the cold, stiff neck, fever, convulsions

– There are known causes - such as drafts, poor job

– Remedy usually lasts longer and the problems do not stop after leaving the building


Indoor Environment and Health

3

32125 YMCB 2013/014

Symptoms of SBS and BRI are identical to themost common health problems.

prof.Karel Kabele

Headache

Cold

Running

nose

Fatigue

Cough

Sore throat

Flu

Joint pain

Back pain

Insomnia

Top 10 health problems of CR population (%)

Which of the following health problems

you have had in the last 6 months?

33125 YMCB 2013/014

• However, what is a healthy building:

prof.Karel Kabele

„Experience with sick building syndrome“

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34125 YMCB 2013/014 prof.Karel Kabele

„Truly healthy building“

• Ventilation and sick leave

• Ventilation and work performance

• Perceived indoor air quality and taskperformance

• Temperature and work performance

36Rehva GB 6

Factors of indoor climate with knownquantitative effects on productivity


5

Rehva GB 637125 YMCB 2013/014 prof.Karel Kabele

Ventilation rates and sick leave

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Rehva GB 6


Temperature and performance

6

39

Adaptation

There may be defined three categories of adaptation to indoorclimate (Folk 1974, 1981, Goldsmith 1974, Prosser 1958, Clark andEdholm 1985):

1. Behavioural Adjustment;2. Physiological;3. Psychological.

The three components of adaptation to indoor climate

(adapted from ASHRAE RP 884)

Adaptation to Indoor Climate

AdjustmentBehavioural /technological changes to the heat balance

(clothing and activity,personal environmental

control)

AcclimatizationLong term physiological

adaptation to climate (genetic adaptation)

HabituationPsychological adaptation –

changing expectations (expectations and thermal

memory, adaptive opportunity)

prof.Karel Kabele125 YMCB 2013/014

HEAT – MOISTURE IETHERMAL COMFORT

125 YMCB 2013/014 53 prof.Karel Kabele

Indoorenvironmentof buildings

Heat -moisture

Air

Lighting

Acoustics

Elmgfield

Psychical

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Heat – moisture microenvironment

…State of the internal environment in terms of heat and moisture flows between the human body and its surroundings ...

Ta

T

p


Heat Exchange Between the Human Body and its Surroundings

• Metabolic heat M

• Heat transfer between the body and the -environment Q– Respiration

– Convection

– Radiation

– Conduction

– EvaporationConvection

Conduction

Radiation

Heat balance equationM = Q thermal comfortM > Q warmM < Q cold

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Factors Influencing Thermal Comfort

• Factors of Human

– Metabolic Heat

– Clothing Insulation

• Factors of Environment

– Air Temperature (Dry-Bulb)

– Relative Humidity

– Air Velocity

– Radiation (Mean Radiant Temperature)



Factors of Human - Metabolic Heat

BasalMetabolism

MuscleMetabolism

Metabolic

Heat

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• Unit 1 MET – is defined as the production of energy of sitting person, when an adult consumes 3.4 ml respectively 3.6 milliliters of oxygen per kilogram of body weight per minute

• 1 Met = 58 W/m2

• 0 up to 16,9 Met



30

50

70

0 10 20 30 40 50 60

W/m

2

AGE

Basal Metabolismx age, sex

MUŽI

ŽENY

Source: Jokl 2002


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Activity Metabolic heat

W/m2 met

Lying 46 0,8

Relaxed Sitting 58 1,0

Work in a sitting position (offices, apartments,

schools, laboratories)

70 1,2

Standing, medium work (salesman, housework, work

on machines)

93 1,6

EN ISO 7730


Jokl 2007


Metabolic Heat

• directly proportional to the surface of the human body

• Human body surface according to Du-Bois

𝑩𝑺𝑨 = ( 𝑯𝟎,𝟕𝟐𝟓×𝑾𝟎,𝟒𝟐𝟓)×0,007184

BSA Body Surface Area cca 1,9 [m2]

W weight in kg,

H hight in cm

• E.g.: 58 W/m2 x 1,8 m2 = 104 W

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Icl Daily common clothing

0,3 panties, T-shirt, light socks, sandals

0,45 briefs, panties, stockings, light dresses with sleeves, sandals

0,5 pants, shirts with short sleeves, light trousers, light socks, shoes

0,6 pants, shirts, light pants, socks, shoes

0,7 underwear, shirts, pants, socks, shoes (panties, petticoat, stockings,

dresses, shoes)

clo < 0,50,6 - 1,2 >3,5

Unit 1 clo=0,155m2.K/W

Factors of Human - ClothingEN ISO 7730

Factors Influencing Thermal Comfort

• Factors of Human

– Metabolic Heat

– Clothing Insulation

• Factors of Environment

– Air Temperature

– Relative Humidity

– Air Velocity

– Radiation (Mean Radiant Temperature)


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Factors of the Environment

Air temperature

State variable describing the kinetic energy of particles of the system.

Thermodynamic /Kelvin/ T [K]

Celsius t [°C] t= T-273,15

Fahrenheit [°F] 1°F=5/9°C (°F-32).5/9 = °C

The air temperature is without the influence of radiation, measured with a

thermometer, protected from radiation heat source.


Mean Radiant Temperature MRT(also effective temperature of the surrounding surfaces, medium temperature of radiation) is defined as the uniform temperature of an imaginary enclosure in which the radiant heat transfer from the human body is equal to the radiant heat transfer in the actual non-uniform enclosure

• where

– tr = mean radiant temperature

– Ti = temperature of the surrounding surface i, i=1,2,....,n

– φrn = shape factor which indicates the fraction of totalradiant energy leaving the clothing surface 0 and arrivingdirectly on surface i, i=1,2,...n

273.T....Tt 4 4nrn

41r1r


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Where top = operative temperature

ta = air temperature

tr = mean radiant temperature (MRT)

hc = convective heat transfer coefficient

hr = mean radiative heat transfer coefficient

rc

rraco

hh

ththt

Calculated value

Operative Temperature

is defined as a uniform temperature of a radiantly black enclosure in which an

occupant would exchange the same amount of heat by radiation plus convection

as in the actual nonuniform environment. It can be defined as the average of the

mean radiant and ambient air temperatures, weighted by their respective heat

transfer coefficients.



go tt Naměření hodnota

Resultant Temperature

(globe temperature) is measured with a globe thermometer, it includes the effect

of air velocity and radiant heat source.

Jokl 1984

Valid for low air velocity (up to 0,2 m/s)

and small differencies between ta and tr

(up to 4 °C),


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Measured value

Stereo temperature

measured directional globe thermometer, includes the effect of air velocity and

uniformity of radiant heat source

Jokl,Jirák2005



Measuringequipment

Documents

125 YMCB Microclimate and Architecture 2 Lecturetzb.fsv.cvut.cz/files/vyuka/125ymcb/prednasky/125ymcb-04.pdf · 2014-03-24 · 1 ČVUT v Praze Fakulta stavební Katedra technických