Bioclimatic Chart 2g6p1b

Università IUAV di Venezia, Environmental Building Physics– Introduction to sustainability Integrated Studio 1 – Master Degree in Architecture and Innovation

Comfort Comfort is the state of mind that expresses satisfaction with the environment Comfort depends on:

Climate and Comfort: Bioclimatic Chart

• • • • • •

clothing Icl activity, Met Air temperature ta Air velocity va Air humidity Ura Mean radiant temperature, tmr

Fabio Peron Università IUAV - Venezia

There is not a single condition of comfort, but comfort conditions are defined by the endless combinations of the six variables.

Sensations are subjective

The feeling is subjective and the same environmental conditions on different persons can lead to different sensations.

Comfort: experimental analysis with group of testers

Comfort metrics: comfort indices

Comfort: energy budget

∑Q

Driven by the proportionality

= Q

K

+ Q

C

+ Q

R

+ Q

between the thermal load of the human body and the feeling of cold and warm proven by man, Fanger in 1970 proposed a new comfort index, the PMV (Predicted Mean Vote)

VOTE

SENSATION

+3 +2 +1 0 -1 -2 -3

very hot hot slightly hot comfort slightly cold cold very cold

PMV = f (Icl, M, ta, va,URa, tmr)

Comfort indices

Qcond - conduction between body and envelope surfaces; Qconv - convection between body and air; QR - radiation between body and envelope surfaces;; – sensible heat associated with Qsi breathing; QLi - latent heat associated with breathing; ED - sensible heat associated with transpiration; - latent heat associated with ES transpiration .

Comfort summary

Thnaks to experimental

Fanger DTU Lyngby (DK)

analyses Fanger can connect the comfort index, PMV, to the environmental and Behavioural

PMV = f (Icl, M, ta, va,URa, tmr)

variables. Starting from the energy budget

PPD = g (PMV)

equation for human body he obtained the following:

PMV = [0.303 exp(−0.036M) + 0.028]S

PMV = [0.303 exp(−0.036 M) + 0.028][( M − L) −

− 0.305{5733 − 6.99(M − L) − pa } − 0.42{(M − L ) − 58.15} −

− 1.7 10 −5 M(5867 − pa ) − 0.0014 M(34 − ta ) −

{

}

− 3.9610 −8 fv (tv + 273)4 − (tmr + 273)4 − fv hc (tv − ta )

Sr

+ Q

Lr

+ Q

Ed

+ Q

Es

Human energy budget: metabolism

Human energy budget: metabolism An adult sleeping or is still lying in bed,

Activity 

therefore produces, as basal

Reclining 

46 W/m2 

0.8 Met 

metabolism a power of 70-80 W.

Seated relaxed 

58 W/m2 

1.0 Met 

Clock and watch repairer 

65 W/m2 

1.1 Met 

values with activities: for a sitting man

Standing relaxed 

70 W/m2 

1.2 Met 

is around 100-110 W.

Car driving 

80 W/m2 

1.4 Met 

Standing, light activity (shopping) 

93 W/m2 

1.6 Met 

Walking on the level, 2 km/h 

110 W/m2 

1.9 Met 

Standing, medium activity (domestic work) 

116 W/m2 

2.0 Met 

Washing dishes standing 

145 W/m2 

2.5 Met 

Walking on the level, 5 km/h 

200 W/m2 

3.4 Met 

Building industry 

275 W/m2 

4.7 Met 

Sports ‐ running at 15 km/h 

550 W/m2 

9.5 Met 

The metabolic power M assumes higher

M is evaluated using a non S.I unit, the met equal to 58,2 W/m2. This

unit

value

corresponds

to

the

metabolic power per unit body surface area developed by a man in sedentary activity.

Human energy budget: clothing thermal resistance 0.5 Clo 1.2 Clo

Human energy budget: clothing thermal resistance Clothing element 

1.0 Clo

Underwear,  shirts    Shirts 

Tros 

clothing is evaluated with a unit Not belonging to the SI: The clo equal to 0,155 m2K/W

Iclu Clo 

Iclu m2 °C/W 

0,15 Clo

Underwear 

The thermal resistance of

Metabolic Rates [M] 

Insulated  coveralls  Sweaters 

Pantyhose  Briefs  Pants long legs  Bra  T‐shirt  Half‐slip, nylon  Tube top  Short sleeves  Normal, long sleeves  Shorts  Normal tros  Overalls  Multi‐component filling  Fibre‐pelt  Thin sweater  Normal sweater  Thick sweater 

0.02  0.04  0.10  0.01  0.09  0.14  0.06  0.09  0.25  0.06  0.25  0.28  1.03  1.13  0.20  0.28  0.35 

0.003  0.006  0.016  0.002  0.014  0.022  0.009  0.029  0.039  0.009  0.039  0.043  0.160  0.175  0.031  0.043  0.054 

Human energy budget: mean radiant temperature

Human energy budget: mean radiant temperature

Is defined as the temperature of the envelope, black and isothermal,

Tmr = 4

of a hypothetical room which would have the same exchange of

∑F T ui

4

i

heat of the real room with the person .

Ti is the temperatura of surface i and FUi is the view factor between man and surface i. Note that the Tmr varies with the location of the person in the room

Standards on comfort

•

•

•

•

Design criteria

ISO EN 7730-2005 Ergonomics of the thermal environment – Analytical determination and interpretation of thermal comfort using calculation of the PMV and PPD indices and local thermal comfort effects.

PMV-PPD and operative temperature design criteria (ISO 7730-2004).

, Class 

EN 15251-2008 Indoor environmental parameters for assessment of energy performance of buildings, addressing indoor air quality, thermal environment, lighting and acoustics. ASHRAE 55-2013 Thermal environment conditions for human occupancy

CR 1752 – Ventilation of buildings-Design criteria for the indoor environment

•

TC156WG12 (European Energy Performance of Buildings Directive) – Criteria for the indoor environmental quality

•

TC205WG5

Building Environmental Design - Thermal Environment

 

)

Comfort requirements 

Temperature range 

PPD 

PMV 

 

[%] 

[/] 

[°C] 

[°C] 

A 

< 6 

‐0.2 < PMV < + 0.2 

21‐23 

23.5‐25.5 

B 

< 10 

‐0.5 < PMV < + 0.5 

20‐24 

23.0‐26.0 

C 

< 15 

‐0.7  < + 0.7 

19‐25 

22.0‐27.0 

Winter(1.0clo/1.2met) 

Summer(0.5clo/1.2 met) 

Climate and comfort: Olgyay chart

Climate and comfort: Olgyay chart This famous illustration is taken from “Design with Climate”, by Victor Olgyay, published in 1963.

You can actually identify two areas of comfort, a summer and a winter one (upper and lower), relating to an scantily dressed (Clo = 0.8), in sedentary activity (Met 1) and in the shade (no solar radiation) .

This is the finite point of expected comfort for 100% mechanical heating and cooling.

The part below the comfort zone describes conditions undercooling, the above overheating.

Green area is the comfort area: we can use different conditions

Climate and comfort: Olgyay chart

Olgyay Chart

Point A Air temperature: 75 °F ≅ 23,9 °C Air Relative Humidity: 50%

A

condition: Summer COMFORT Winter COMFORT (limit)

No intervention: It falls into the comfort zone

Olgyay Chart

Olgyay Chart

B

Punto B Temperatura a bulbo secco aria: 75 °F ≅ 23,9 °C

Punto C Temperatura a bulbo secco aria: 50 °F ≅ 10 °C

Umidità relativa: 70%

Umidità relativa: 56%

condizione: non COMFORT

condizione: non COMFORT

accorgimento necessario: Moto aria: 120 fpm ≅0,61 m/s

C

Olgyay Chart

Olgyay Chart Punto E Temperatura a bulbo secco aria: 95 °F ≅ 35 °C

Punto D Temperatura a bulbo secco aria: 87 °F ≅ 30,6 °C

D

accorgimento necessario: radiazione: 250 Btu/(h ft2) ≅ 788 W/m2

Umidità relativa: 30% condizione: non COMFORT accorgimenti necessari: vento: 300 fpm ≅ 1,52 m/s oppure vapore d’acqua: 8 grains/pound ≅ 1,14 g/kgas

E

Umidità relativa: 20% condizione: non COMFORT accorgimenti necessari: vento: 700 fpm ≅ 1,52 m/s in più vapore d’acqua: 8 grains/pound ≅ 1,14 g/kgas Oppure vapore d’acqua: 22 grains/pound ≅ 3,14 g/kgas

Olgyay Chart

Olgyay Chart Some modifications to the original Olgyay chart:

In the chart some others lines related to specific conditions:

Substitution of sun radiation (typical of external environment) with mean radiant temperature Tmr (typical of internal environment).

• • • • • • • • •

Added different clothing resistence levels reaching comfort

Climate and comfort: Olgyay chart

In the diagram, you can report the climatic conditions of the site considered, highlighting the " climate criticities" in relation to the comfort .

colpo di sole colpo di calore congelamento delle dita limite di congelamento limite di sopravvivenza limite per certe attività limiti per vestiario condizioni di troppo secco condizioni di troppo umido

Olgyay chart: considerations The Olgyay Bioclimatic Chart is usefull for buildings design when air temperature inside the building is next to the outside: it happens in the summer at mid and low latitudes for humid climates , and is especially true as more buildings are light and naturally ventilated by opening doors and windows . In Olgyay chart it does not consider the presence of the building

Venice climate is humid with cold winter. Warm periods with high humidity (scirocco wind, summer sultriness).

The plot is not very effective for massive buildings in hot, dry climates: here the indoor air temperature is always very different from the outside, without any HVAC System. In these cases the signs of Olgyay lead to overestimation of the interventions to ensure comfortable conditions .

Givoni chart

Givoni chart

To get around the problem that can arise from the direct use of external climatic data in the chart, Baruc Givoni in 1969 proposed a new bioclimatic chart “Building Bio-Climatic Chart” based on ASHRAE humid air diagram and integrating the building factor..

CE CI

Givoni chart

Givoni vs Olgyay Charts Differences between Givoni and Olgyay Charts: •

Givoni consideres the presence of the building

•

In Givoni winter comfort zone is much larger than the summer(assuming heavier clothing and more intense activity)

•

Are traced areas where the conditions of external temperature and humidity can ensure indoor comfort using ive Systems. They consider four main systems: a) ventilation b) high mass c) radiation collection d) evaporative cooling the comfort zone boundaries are determined by the internal temperatures provided by the building without plant and bioclimatically designed.

Brown Chart

Brown Chart

Brown, De Kay 2001

Brown Chart

Brown, De Kay 2001

Brown Chart

Madison (Wisconsin): Charleston (South Carolina): Natural ventilation can be sufficient for cooling needs

Natural ventilation can be sufficient for cooling needs

Sun radiation isn’t sufficient for the heating needs (very cold climate).

Sun radiation can be sufficient for the heating needs

Brown, De Kay 2001

Brown, De Kay 2001

Innovation and comfort: the adaptation The context and the thermal history of each subject can change the expectations and climatic preferences. It is the so called adaptation which is the process of gradual decrease of the reactions of each subject to the microclimate stimuli behavioral adaptation (clothing, posture, activity) It is the overall changes that a person puts into action, consciously or unconsciously, in order to change the parameters that regulate the heat balance of the body. It can be personal, technological and cultural. physiological adaptation prolonged exposure to a certain type of environment or climate, reduces thermal stress. This adaptation can be genetic or acclimatization. The physiological adaptation has a negligible influence on the perception of comfort in moderate environments. psychological adjustment (expectations), previous experiences and expectations change the perception of sensory stimuli and the reaction to them.

L’approccio adattivo al comfort si basa sul principio di addattatività: Se avviene un cambiamento che produce discomfort, le persone reagiscono in modo da ristabilire il loro stato di comfort Questi cambiamenti si hanno su periodi di tempo variabili e possono essere cambiamenti effettuati sulla persona o sull’ambiente. istantanei: mettersi o togliersi indumenti in risposta o anticipando cambiamenti di condizioni nel giorno: risposta a cambiamenti di ambienti durante il giorno giorno per giorno: risposta a cambiamenti meteorologici lungo periodo: risposta ai cambiamenti stagionali guidata dal contesto culturale Il comfort è visto come il risultato di un’interazione tra edificio e occupanti in un certo contesto climatico e culturale. Le condizioni di comfort cambiano con i cambiamenti di vestiario e con altri fattori in funzione della stagione e del clima. Lo studio di questo sistema di retroazione naturale ha dato dei risultati riproducibili.

Adaptation Comfort is achieved by the occupants adapting to the building

Occupant

Building

Or by the occupants adapting the building to suit them All this in a specific social, economic and cultural context

Proportion of subjects comfortable

Adaptation

Innovation and comfort: the adaptation

1 0.9 0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1 0

Little discomfort

12 14 16 18 20 22 24 26 28 30 32 34 36 38 Mean indoor temperature oC Comfort level with various indoor temperature. Investigation in offices in Pakistan Nicol, Raja, Allauddin & Jamy (1999) Energy and Buildings 30

Adaptation

Adaptation

Comfort temperature

35

30

25

20

15 10

15

20

25

30

35

40

Mean temperature experienced

Comfort and mean external temperature in Pakistan Nicol, Raja, Allauddin & Jamy (1999) Energy and Buildings 30

Adaptation

50 F

59 F

68 F

77 F

86 F

95 F 86.0

24 22

NEW DELHI

BANGKOK

PALERMO

TOKYO PERTH

TORINO

STOCKOLM AMSTERDAM

26

FRANKFURT

28

SINGAPORE

30

o

indoor operative temperature ( C )

32

Adaptive comfort and Fanger model

82.4 78.8 75.2 71.6

90% acceptability limits

20

68.0

18

80% acceptability limits

64.4

16

60.8

14 5

10

15

20

25

30

35

o

mean monthly outdoor air temperature ( C)

ASRAE 55-2004

Adaptation

Adaptation

According to a 2009 study developed in the European offices, the comfort temperature, Tc, varies as a function of the mobile mean of external temperature, Trm, following the relashion:

Tc = 0,33 Trm + 18,8

Also in Europe is considered the adaptation: CEN EN15251-2007

Natural ventilation and comfort

Adaptation

•

•

The standards indicate a constant temperature inside the buildings to obtain comfort. Research in different parts of the world have put in evidence how the temperature that is perceived comfortable varies with season and climate This means that comfort can be achived with less energy in a building where the internal temperature follows the outside temperature This means that in a well designed building we can obtain comfort conditions also without HVAC systems

AC buildings, line B Neutral or comfort temperature oC

•

34 Free-running buildings, line A 32 30 28 A

26 B

24 22 20 18 16

Tn = To

14 12 -24 -22 -20 -18 -16 -14 -12 -10 -8 -6 -4 -2 0

•

It was developed an algorithm for the prediction of the comfort temperature as a function of the outside temperature Using this algorithm to control the set point of the air conditioning you can save 25% of energy.

2

4

6

8 10 12 14 16 18 20 22 24 26 28 30 32 34 o

Monthly mean outdoor temperature C

Humphrey in1978 from field studies. Each point represents a research campaign. In free-running building expectations are less stringent.

Natural ventilation and comfort

Innovazione e comfort personalizzato

Brager and De Dear 2006: non ci sono errori ma un adattamento psicologico legato all’esperienza personale e alle aspettative Fabio Peron – Argenta, 10 settembre 2016

Innovazione e comfort personalizzato

Sistemi di ventilazione e controllo personalizzato

Sistemi di ventilazione e controllo personalizzato

Innovazione e comfort personalizzato

Sistemi di ventilazione e controllo personalizzato

Bioclimatic Chart and comfort model

Innovazione e comfort personalizzato

scaldagambe

Poltrona riscaldata o raffreddata;

Bioclimatic Chart and design evaluations

Bioclimatic Chart and design evaluations

Climatic needs

Bibliografia

Climatic needs