Evaluating the Efficiency of Different Cover Forms of the...

17

Evaluating the Efficiency of Different Cover Forms of the Large Spans in Flowers and Plant Exhibitions Based on the Natural Ventilation

System in a Moderate and Humid Climate.

Alireza Soltanzadeha, Katayoun Taghizadehb,*, Jamshid Emamic

aM. Arch., Architecture Department, College of Fine Arts, University of Tehran, Tehran, Iran

bAssociate Professor, Architecture Department, College of Fine Arts, University of Tehran, Tehran, Iran

cMember of The Industrial Design Department Scientific Board, College of Fine Arts, University of Tehran, Tehran, Iran

Received: 5 October 2017 - Accepted: 25 December 2017

Abstract

Deciding the roof type with a large ventilation spans for uses in the flower and plant exhibitions that can operate beyond the exhibition space functions as it can provide a desirable climate for the growth of its plants, it can be designed and enhanced according to the geographical site of it. Deciding and designing the roof form can prevent dissipations in energy and assets and develops a construction with high efficiency together with low costs of maintenance, only if it is done in an intelligent way. The independent variables in this research are the climate conditions, and form of the structure is considered as the intervening variables together with factors like the internal air current and sub climates and the levels of thermal comfort for individual occupants as the dependent variables. The aim of conducting this master thesis which is considered as an interdisciplinary research, is to reach for proper patterns in covering the ventilators in greenhouses with large spans by using the climate information of the north-Iran region. The main question of this research is the most efficient roof form in regard to natural ventilation in mild and humid climate condition? Research method the study is modeling and computer simulation in a way that they are evaluated with the prevalent forms of exhibitions and greenhouses with large vents in the terms of the external wind flow impacts and natural ventilation in their interior and analyzed by employing Computational Fluid Dynamics (CFD) and moving particle semi-implicit (MPS) simulation. Results indicate that form of a building has an obvious impact on the internal airflow and the curved forms have a better impact on the internal circulation of air. As an instance, in the convex geometries, the airflow speed rate drops in the center of the construction while in the concave geometries it is quite the opposite as the speed is reduced around the sidewalls of the construction and the thermal comfort becomes a different point along with natural ventilation.

Keywords: Exhibition Roof, Geometrical Form, Natural Ventilation, Computational Fluid Dynamics (CFD), Thermal Comfort.

1. Introduction One of the most important issues in the greenhouses with large spans is to develop and control suitable conditions for the ventilation. According to the research (Baeza, E. J. et al. 2007), the best way for cooling the greenhouse is to employ natural ventilation which should work along with a mix of efficient air exchange in order to discharge the high-temperature air that is done by a specific desirable condition under the roofing of greenhouse. The form of roofing, number and placement location of ventilator spans has a noticeable impact on the improvement of the air flow and the possibility of developing natural ventilation. There are a variety of options for deciding different geometries for the roof of the greenhouses with large ventilation spans. The geometrical potentials for each of these roof types regarding the efficient feedback compared to the natural flow of the

wind according to the necessity of efficiency and points revolving the sustainability in planning and construction of such buildings. According to (Bartzanas, et al. 2004) since most of the greenhouses in the world employ natural ventilation in order to cool down the greenhouse during the hot season of the year and to absorb the humidity of the air during the cold seasons and also to provide carbon dioxides from the fresh outside air. For the greenhouses with broad and geometrical shapes with low heights, the difference between the intake shutters and exhaust pop-up vent should be increased for the ventilation to work well (Perén, J. I., et al. 2016). Type of the climate is a decisive factor in choosing the geometrical shape of the ceiling for an enhanced ventilation. As an instance, for the case of moderate and humid north-Iran climate due to the comparatively high humidity of the air which is considered

* Corresponding author Email address: [email protected] article is extracted from master thesis of first author.

Space Ontology International Journal, Vol.6, Issue 3, Summer 2017, 17 - 36

18

as a perfect climate for agriculture in Koppen-Geiger classification, and the possibility of analysis and evaluations over deciding the type of ceiling geometry by computational methods and simulations. The main question of this research is the impact of wind on the roofing shell with the form of a greenhouse with large spans in a temperate and humid climate. According to the present concerns on the topics related to sustainability and also by acknowledging the scarcity of energy sources, in order to construct a sustainable building certain specification of the construction site climate and conditions should be simulated toward the issues of ventilation, etc., to avoid energy dissipation and unrecoverable damages to the environment. According to the developments in technology and computer simulations through the past decades, observation has been made on greenhouses with wide spans as the wind-tunnel together with manual experimentations were used for this purpose in the past. With the use of computational fluid dynamic (CFD) methods we can simulate the function of wind under the ceiling. We can evaluate the conditions that occur under the ceiling in different times of the year by employing these proven methods and predict some facilities to supply in regard to the placement of pop-up ventilator spans together with their number and size in order to identify the frames that brings the best feedback in the ventilation process. The applied points in the simulations include the relocation of heat and airflow and thermal comfort for human beings and plants.

1.1.

Literature Review

Different studies are conducted on the subject of the windflaw in the interior spaces with wide spans, including the work of Mr. (Ameer, S. Et al, 2016) which inspected different forms of ceilings and their functions toward the distribution of interior air flow in the scale of small urban buildings. A number of five ceiling types are evaluated in this research: Flat, pitched or gabled roofs with different heights together with shelving curved roofs, the wind speed potential in developing natural ventilation under the roofs was analyzed in the different type of the roofs as the final results for the gabled roofs with different heights were compared with the ASHRAE and CIBSE standards and it is nominated as the best form. Another issue that greenhouses with wide spans would face is the correct position of the pop-up ventilators, in his research (Khaoua. S, 2006) on the subject of locating ventilator pop-ups in front or opposite to the wind and comparing the efficiency of the mentioned methods for an external wind with a 1 mile per second (1 m/s) and the weather temperature of 30 degrees centigrade the ventilation rates were calculated accordingly between 9 to 26.5 for the pop-up ventilator spans facing the wind and 12.7 to 3.7 for the spans opposite to the wind. Although, according to (Bartza-nas et al. 2004) it indicates that the best ventilation

rates do not necessarily signify the best function in the greenhouse. According to the research of (Kim et al, 2010), the efficiency of ventilation in surrounded spaces depends on other factors including currents of the external wind, type, and height of the pop-up ventilator spans. On the subject of singularity or plurality for the number of pop-up spans in the greenhouses, in (Rico- Garcia, 2006), researchers concluded that ventilating a greenhouse with a tall ceiling and long windows is better than those greenhouses which include numerous ceiling spans, and the fact that the role of air temperature on flowing the air and provide natural ventilation raises in hot climate conditions altogether with the air transfer rates. In greenhouses with broad intake spans, environmental factors should be provided in desirable for the plants in the terms of temperature and humidity in addition to the thermal welfare of the visitors. In a study by (Roy, J. C., et al. 2008), a research was made on the temperature and humidity level on the surface of the plants by using Computational Fluid Dynamics (CFD). A major number of studies regarding the use of CFD in architecture is related to the buildings with medium scales and in order to simulate the mutual ventilation between them, as the research of (Ramponi. R, 2012) has a focus on various different parameters including: development of the calculation field, clarity in the development of network calculations, turbulent kinetic energy after the border of atmospheric layers, values of each simulation. If we pay to more detail to the impacts of airflow in the interior spaces of a greenhouse and a plants exhibition place with a broad intake spans, we should consider the existence of trees with different heights and their impact on the internal flow of the air. In the research of (Endalew. A., 2009), the impact of the wind speed on the trees by computer simulation together with real simulations in smaller scales in the wind tunnel. Results indicated that growth in density of the trees crest would decrease the airflow speed in the lower parts of the tree. An important topic of the analysis is to survey a combination of transferential energy simulation in the building and the interior airflow. In (Zhai, Z. et al. 2004), in order to reach a natural convection in the building, a grid pattern with the distance of 0.005 meter and the distance of 0.1 meter for forced convection of the interior air. Only a few of studies are done about the applications of (CFD) in the context of architecture and the work of (Kaijima, S., Bouffanais, R., Willcox, K., & Naidu, S. (2013) is one of the rare studies which is conducted by the architects regarding the connection between CFD and its application in architecture. This research uses a toolkit that facilitates the CFD illustrations for the architects, which can help to convert the exports from Fluent software together with Rhino 3D modeling software into sets of meaningful visual compositions for the architects. Another study has an

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21

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3. Data Collection

The first topic is to discover about the climate condition of the research area (Lahijan city). More than one sources were used to take geographical data including the following factors:

● Maximum and minimum temperature (°C) ● Field of sight (km) ● Air pressure (mb) ● Percentage of cloudy weather possibility (%) ● Humidity in percentage (%) ● Maximum and minimum wind speed (m/s) ● Average storm frequency ● Number of foggy days ● Per capita for the rainy and cloudy days

● Snowfall rates (cm) ● Rainfall rates (Mm) ● Ultra Violet (UV) rates.

Description of the weather in Lahijan

The dry season of the year is not persistent (for near a month during June) and the rainfalls are present in most of the cases. Rainfalls are not in the same level for all regions in the province and the freezing days were scarce and scattered as the temperature barely reaches a -1 degrees in centigrade. According to the chart of windflow in Rasht, it is dominant in the west direction which also include northwest in some of the seasons in the year. Although in the months of June and July the air humidity develops difficult sultry conditions which would generally be broken with summer rainfalls in the north and a desirable thermal condition will be replaced.

Table 1 Climate chart of Lahijan. (Source: Lahijan synoptic station located in Falahat garden, 2016).

Annual Temperature average 17.1°c Minimum average annual air speed

2 ms-1

Average of annual maximum temperature 22,1°c Annual average of air speed 3 ms-1

Average of annual minimum temperature 12.2°c Maximum annual humidity in October

87%

Difference between the minimum and maximum temperature through the year

9.9°c Minimum annual humidity in July

56%

Average temperature in the coldest month of year (January)

1.1°c Average Annual air humidity 75%

The average temperature in the warmest month of the year (August)

33.9°c Maximum annual air pressure in November

102460 pa

Average annual maximum air velocity in spring

20.3°c Minimum annual air pressure in July

100970 pa

Average annual maximum air speed in summer

26.6°c Average annual air pressure in July

101635 Pa

Average annual maximum air speed in autumn

13.9°c Annual average of sun radiation 14.8Mj/m2

Average annual maximum air speed in winter

7.6°c Maximum annual sun radiation in July

24.6Mj/m2

Average annual maximum air speed 4 ms-1Maximum Annual Radiation of the Sun in december

6.2Mj/m2

4. Studied Models

Different greenhouses and exhibition spaces for plants and flowers are constructed in the world with different forms and in different climates throughout the history, each of them is planned and constructed by famous architects with their own specifications, this levels of experience can act as a pattern for further studies. The modelled forms are developed based on the form of these greenhouses together with different geometries for a better comparison.

6 Modelling is based on the previous constructed forms of greenhouse or spaces with flower and plant exhibition purposes and two other samples are different form than these six types which are introduced in order to test the function of internal airflow pattern. The ventilator of these six models were fixed and a number of 6 air intake shutters were considered on the sidewalls and one exhaust air vent is designed on the top of each models. The simulation conditions which are listed in the tables 4, 5 and 6 are applied equally for all of these models.

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ant issue that hat the geomeide the thermaerior space, the

between the owing paramet

s pattern of thef the internal af air movementperature redicted PercenMean Radiant T

redicted Meanty

and Fig. 8. Typ a section of t

equations and flations in ord

mation of the e9.It is the volu

s to the observ

on 9.

for the thermthe terms of verate based on

ACPH) is the m

lowable wind s

is studied in ttry of big buil welfare and erefore, differe

simulated moers:

e flow irflow t

ntage of DissatiTemperature) n Vote)

pe of the current the exhibition’s

formulas as theder to reach aevents that areume current ofation space.

mal comfort ofentilation in the

the number ofmeasure of the

speed for the vWind conditWind VelocWind Veloc

Wind Veloc

Wind VelocWind Veloc

this research isildings for thethe movementent geometries

odels are done

isfied people)

and the airflow plength and the a

24

eaef

fefe

air vois theThis and ithe sphendynaspacesimuEvaluaveravisitoimpo

visitors. (Sourcetion

city < 3.9 m/s city < 6.1 m/s

city < 8.3 m/s

city > 8.3 m/s city > 25 m/s

sets

e

6. Sim

All ocomptempthermairfloshapeexhib

ExtrGreeIn thexhauthe rleveltempairflowas e

pattern is observairspeed in the en

olume added te density of thequation is us

it will also hesoftware. Thes

nomenon that amics and the de, etc., and th

ulation and comuating the poage internal aors who spenortant criteria fo

e: Shane, F. 20ExtenAccepAccepand otAccepand otInacceDange

mulation and

of the 8 modelspared on theperature, speedmal comfort aow currents. Ae of the diagrabition visitors.

racted resultenhouse he anticlastic ust vent with

roof by considls of humiditperature levels,ow pattern andevaluated in th

vable on the righntrance and exha

to or removed he crowd, h issed in order to

elp for checkinse equations d

happen in distribution ofhis is the mai

mputational fluioint that whichairflow has and time in thfor evaluating t

011) nt of welfare

ptable for moderptable for walkither moderate mptable for walkither strict activiteptable for walkerous for walkin

Results

s were simulatee terms of d of the wind aand to analyzAll of the expam based on th

ts from th

geometry, sim3 in 3 meter dering six air inty in the sur, speed of the d finally the Prhis simulation.

ht image while oaust of the air is

from a space is the height ofo develop subjng the exportindoes not covereality as the

f temperature fin reason thatid dynamics (Ch one of thes

a negative imhe exhibition the ceiling effic

rate activities ing, standing

movements. ing, ongoing, ties.

king ng

ed in equal conchanges in

and humidity tze and compaported data arhe standing po

he Anticlasti

mulation is dodimensions is dntake shutters.rface of huminternal windf

redicted Mean

n the right imagevident.

in an hour, D f the ceiling. jective space ng data from er all of the e air-related for a specific t we use the CFD). se forms the

mpact on the is also an

ciency

nditions to be the weather together with are different re under the osition of the

c Modeled

one with an developed on . Factors like an standing, flaw, internal Vote (PMV)

ge


ExThe

o

tracted resulte internal airflo

Fig. 9. and Figof the exhibition

Fig. 11. and Fthe

Fig. 13 and Fig

ts from the conow speed:

Fig 15 and F

g. 10. diagram ofspace length and

Fig. 12. Diagrame left image and

g. 14. PMV indexand on the righ

ne greenhouse

Fig 16: Type and

f the wind speedd the amount of

m of the fluctuatithe chart of chan

x of thermal welht the pattern and

e:

d pattern of airflare show

25

d in the exhibitionair speed near th

ions in the exhibnges in humidity

lfare on the situad temperature lev

Evaluhumiair in

ow is shown on wn in the left ima

n is shown in thhe air intake and

bition in the exhiy is shown in the

ated people in thvels of the space

uation of the idity are applientake frames in

the right while tage.

he left image andd exhaust frames

ibition space is se right image.

he exhibition in oe is shown.

internal airfloed on a 1.80 m

n a diametric lin

the airspeed flow

d a section s in the right.

shown in

observable

ow speed, temmeter distance ne.

w rates

mperature and between the


Theopesidoutcoepatcen2.5areof caro

F

Fig

Fig

e air temperatuening and onewalls due totside temperatuefficient of thttern is decreanter of the cons5 meters. Pattee reduced in a construction as

ound the wide w

Fig. 17 and Fig 1the right i

19 and Fig 20.

g. 21. and Fig. 22in

ure stays fixedly increases w

o the differenure and by conhe glass sidewasing from thestruction and thrns of the air similar form ws the temperatuwalls.

18. Airflow patteimage and the te

Temperature p

2. The air densitnternal air is sho

d in the middlewhen it gets

nce between thsidering the he

walls. The inte air intake ophis change reacdensity and h

when approachure and humidi

ern and the extenemperature dispe

pattern is evideair speed is s

ty in the 16 meteown on the sectio

e of the intakecloser to the

he inside andeat temperatureernal airspeedpenings to theches a value of

humidity chartshing the centerity is increased

26

nt of thermal comersion in the env

ent on the 16 mhown in the 16

ers is shown on ton of the constru

eededefsrd

Extr

This AustrThe wLahijreachamouSeptegreendensiand yfront

mfort based on tvironment is show

meters on the ri6 meters.

the right image wuction on the 16

racted results f

greenhouse tralian architecweather and cljan city in a hes for 30 ceunts of rainfember. In the nhouse, with a ity in the spacy planes accot of each other.

the PMV index iwn in the left im

ight image whi

while the humidimeters of it.

from Adelaide

was designct Guy Maronelimate of Adelway that the entigrade ovefalls reaches greenhouses i

a long dimensioce is simulatedrding to the p.

is shown on mage.

ile the internal

ity rates of the

e greenhouse

ned and cone in Adelaide laide city is vemaximum air

er nights and for 177 mi

in a big-type lons, the airflowd with two perplacement of v

nstructed by city in 1988. ery similar to r temperature

the highest illimeters in like Adelaide w pattern and rpendicular x ventilators in


Weath

Fig.

her information

. 23 and Fig. 24.th

Fig. 25. an th

Fig. 27

of Adelaide city

Fluctuations in he left while the

nd Fig. 26. The qhe air speed in th

7. and Fig. 28. Fthe rates o

y in 2006. (Sourc

the air current stype and pattern

quality of air mohe 20 meters spa

Fluctuations in thof changes in the

27

ce: en.climate-da

peed in the 10 mn of the airflow c

ovement in the grace of the greenh

he temperature ise air humidity is

ata.org)

meter radius of thcurrent is shown

reenhouse is evihouse is evident

s shown on the rs shown on the ri

he greenhouse isn in the right.

ident on the left won the right.

right image whilight.

s observable on

while

le

Tablee 8


ExConKe

TabWe

tracted resultnstruction of Aw, in the sub

ble 9 eather informatio

ts from AlpineAlpine plant eburbs of Lon

on of London cit

Fig. 30. The

Fig. 31. and Figleft im

Fig. 29. Thw

e greenhouse: exhibition spacndon by the W

ty in 2006. (Sour

airflow speed inty

g.32. Fluctuationmage while the c

hermal comfort owhich is calculate

ce was done inWilkinson Air

rce: en.climate-d

n the length of grype and pattern

ns in the air tempchanges in the ra

28

of the people situed based on the

nr

archiLahijand J

data.org)

reenhouse is indis shown in the r

perature levels inates of air humid

uated in the exhiPMV index.

itecture groupsjan but has a hJanuary.

dicated in the leftright image.

n the length of grdity is shown in

ibition

s in 2006. Kewhigher humidity

ft image and the

reenhouse is shothe right image.

w has a weathy rate of 80%

air flow

own in the

her similar to in December


ExThibioair

tracted resultis greenhouse

osphere in the Gtemperature

Fig. 33. and Figleft im

ts from Bola be was designGeneva, italy band pressure

Table 10 Weather inf

Fig. 36 and Fig.

g. 34. Fluctuationmage while the c

Fig. 35. T

iosphere: ned and consby Renzo Pian

of it and th

formation of Gen

37. Type and pachanges

ns in the air temchanges in the ra

he PMV index l

structed as ao in 1996. The

he airspeed in

neva city, Italy.In

attern of the airfs in the airflow s

29

perature levels iates of air humid

evel is observab

aen

Genethat rcond

n 2006. (Source:

flow is shown in speed in the exhi

in the length of gdity is shown in

ble on a value of

eva is similar treaches for a r

dition in Lahijan

: en.climate-data

the left image wibition is indicat

greenhouse is shthe right image.

f -0.6.

to Lahijan but rate of 85% is

an.

a.org)

while on the righted.

hown in the

the high level30% more hu

ht image the

l of humidity umid than the


Ex

Fig

tracted result

g. 38 and Fig. 39

Fig. 40 and

ts from Brisba

Fig. 42 andi

Fig. 44 and Figcentigrade toler

. The rates of fluthe amou

Fig. 41. The PM

ane greenhous

d Fig. 43. Type aimage the chang

g.45. The levels orance while in th

uctuations in theunt of fluctuation

MV index is showpat

e:

and pattern of thes in the airflow

of fluctuations inhe left image wh

30

humidity of exhns in the air temp

wn in the left imttern is shown.

It is lof hu

e airflow is showw speed is indicat

n the exhibition ile the amount o

hibition space is perature is indica

mage and on the r

located in Queumidity, it has

wn in the left imted with a 1.4 m

space temperatuof fluctuations in

shown in the leated.

right image the a

ensland, Austra humidity sim

mage while on them/s tolerance.

ure is indicated wn the humidity is

ft image while

airflow

ralia. With a himilar to Lahijan

e right

with a 0.13 s indicated.

igher degree n.


Fi

ExSyd

ig. 46 and Fig.47

tracted resuldney.

Fig. 5

7. The airflow pa

lts from the

Table 11 Weather da

Fig. 48 and Fig

50 and Fig. 51. Tdegrees in ce

attern and the air

e Muttart g

ata of Sydney cit

g. 49. Type and pthe changes in

The levels of flucentigrade in the l

r temperature is shown

reenhouse in

ty in 2006. Sour

pattern of the airn the airflow spe

ctuations in the eleft image while

31

shown on the rigin the right imag

n SeasoSydnamou

rce: en.climate-d

rflow is evident eed is indicated w

exhibition space the amount of f

ght image and thge.

ons with highney are differenunt of humidity

data.org

in the left imagewith a 2.5 m/s to

e temperature is ifluctuations in th

he PMV index w

h levels of hnt with Lahijany throughout th

e while on the riolerance.

indicated by a tohe humidity is in

with a desirable h

humidity and n, but Lahijan he year.

ght image

olerance of 0.025ndicated.

high degree is

rainfalls in has the more

5


Exin LIn No

Thespe

tracted resultLondon the simulation

orman Foster

Fig. 54

Fig. 5

Fig.

e results have eed, humidity

Fig. 52 and F

ts from the Ke

n of this gardin 2000, a

4 and Fig. 55. Thleft hand whi

56 and Fig.57. Lwhile on the

58 and Fig.59. T

indicated thatand temperatu

Fig. 53. The qual

ew Royal Gre

den which is similar geome

he quality of air le on the right si

in take

Levels of fluctuate right hand we

The quality of aion the model sh

t in this table aure of air is t

ity of air movemcomfort index

at Glasshouse

conducted byetry which is

movement withide changes in spe frames which in

tions in the tempcan observe the

ir movement is ehows that the col

about the flowaken from the

32

ment is evident ox is shown on th

e

ys

modedone

h the maximum speed is indicatedncreases to 0.5 m

perature with thefluctuations in h

evident on the leld air is located a

we

on the left imagehe model.

elled as a secte according to t

speed of 2 meterd which is in its mmeter per secon

e tolerance of 0.0humidity with th

eft image while tat the bottom of

e and the level of

tion of a donuthe real air inta

rs per second is omaximum amou

nd.

08 degrees centihe tolerance of 0

the PMV thermaf the model.

f thermal

ut shaped geomake and exhaus

observable on thunt in the

grade on the left.003%.

al welfare index

metry as it is st frames.

he

ft


stanwh

nding positionhat the external

of the visitorsl form have ma

s which indicatade on the inter

tes the changesrnal conditions

ss

and tthe air intake.

Co

1.

Acstopdis

It ieveacc

2.

Acdurmotem

Fig

Table 9 Data exp

Anticlastic

Cone

Adelaide

Alpine

Bola

Brisbane

Sydney

Great Glasshouse

omparison betw

Based on the l

cording to the p at a certainability in the in

Fig. 60. Comparoutside

is evident thaen the anticlacordingly in co

Based on temp

cording to thring the summost difference mperature.

g. 61. Comparisothe intern

port from the sim

PMV

Warm

The feet Slightly w

Slightly warm

Neutral Rate

Slightly warm

Slightly warm

The feet Slightly w

The feet warm

ween the simu

levels of humid

fact that the hn degree, thernterior of the e

rison between the and inside of th

at the Adelaidastic form haomparison to th

perature chang

he fact that thmer, the best po

between th

on between the tnal and external a

mulations.

PPD

Dissatisf

Most diupper pa

warm

70% Sati

High sati

High dis

Most diupper paSatisfactwarm

Most diupper pa

ulations

dity

humidity level refore it indicexhibition area.

he humidity diffehe research mod

de, Sydney greave gained behe other models

ges

he simulation oint would be

he inside and

temperature diffarea of the green

fied

ssatisfaction occurts of the body isfaction

isfaction

satisfaction

ssatisfaction occurts of the body ion in all parts of b

ssatisfaction occurts of the body.

is supposed tocates the most.

erence for the dels.

eenhouses andests of resultss.

is performedto achieve the

d outside air

ference between nhouse.

33

MRT

0.03°c 0.22°c

urs in the

0.6°c 1.3°c 0.14°c 0.065°c

urs in the

0.012°c

body

0.37°c

urs in the

ot

ds

der

The bkeepdesir

3. BSevewindIn this mo

Fig.

4.

The whicequalenclo

HuTemperature

R

0.00.03°c 3

0.00.13°c 2

0.00.5°c °

0.01.3°c °

0.00. 06°c 4

0.00. 13°c 6

0.00.025°c

1

0.00.08°c 7

best efficiencys the greenhou

rable degree co

Based on the fluere fluctuationsd will result in uhis instance, thost desirable.

62. Comparisonair spe

Based on the M

uniform tempch the radiant l to the radianosure.

Fig. 63. Coto the

Vumidity

20015%

4008%

600026%

1036 %

3006 %

1005 %

2001 %

2003 %

y is won by Alpuse cooler in somparing to the

uctuations in ths and changesunwanted resu

he lowest possi

n between modeeed inside the ex

Mean Radiant

perature of anheat transfer

nt heat transfer

omparison betwee resulted rates o

LoAg

Velocity

M2.1 m/s

M4.1 m/s

M6 m/s

M1.2 m/s

M3.1 m/s

M1.4 m/s

M2.51 m/s

M2 m/s

pine exhibitionseveral internae outside tempe

he wind speeds in the speed

ults on the user ible of changes

els in regard to chxhibition space.

Temperature (

n imaginary from the hum

r in the actual

een models in regof MRT index.

ocal Mean ge

Max: 1.3 min

Max: 1.9 min

Max: 1.4 min

Max: 1 min

Max: 1 min

Max: 1 min

Max: 3 min

Max: 7 min

n space which al spaces to a erature.

d of internal of the space.

s in the rates

hanges in the

(MRT)

enclosure in man body is non-uniform

gard


5

Fi

6. Peodefwit

Fig

7. B

PMa lasev

Fig

.

Based on Lostreams that pexhaust

ig. 64. Average o

Based on Preople regardingfies a quantitath thermal com

g. 65. Percentageof th

Based on the P

MV is an index arge group of ven scores.

Table.8 PMV index

Value 3- 2-

1- 0 1+ 2+ 3+

Source: Y

g. 66. Satisfactiothe

ocal Mean Agepass through f

of presence timespace of the e

edicted Perceng thermal welative estimatio

mfort.

e of the visitors se exhibition, bas

Predicted Mean

that predicts thpeople based

Yao, R., Li, B., &

on rates of visitorexhibition based

e (LMA) the afrom the local

e for the fresh airexhibition.

ntage of Dissalfare PPD is n of the dissa

satisfaction in dised on PPD inde

n Vote Index (P

he mean comfoon the therma

SensitivityVery cold

Cold

Slightly coldNeutralSlightly warmWarm

Very hot

& Liu, J. (2009)

rs, situated in difd on PMV index

average time ofl region to the

r in the interior

atisfied (PPD)an index that

atisfied people

fferent locationsex.

PMV)

fort response ofal sensitivity in

fferent places ofx.

34

fe

)te

s

fn

f

7. Co

Diffecurreefficion thspacethe wof paof cospeedanticchangchangdifferreflecAndindexwhicand tgrowexhibconcafor itthermand texhiborderenergenergmain●

Rlaen

●

Tclsp

●

Inglinvein

●

Ccohu

In theconsiplantcause2. Aventiof cothe pventiconte

onclusion

erent geometrient and interiiency of functi

he natural vente and the level

weather of Lahiatterns, as we wonstructions wid over the e

clastic form. Ages in humidiges in the temrences amongct the functionthe mentione

xes of thermal ch the lengths those with con

wth in the ratesbition space. Bave shape, thets minimum le

mal welfare in the importancebition spaces ar to reach for gy is pertinent gy and reducesntenance of the Results indicatesayers in the larnhancing the th

There is a fundlimate and formpans. n the mild anlasshouse increncrease in the hentilate and sncreases.

Concave forms ompared to theumid climate. e following stuidering the plats and flower ed in the intern

Also the locatilation can studonsidering to dplants in greeilation can be ext.

ies of a buildiior temperaturion of differentilation and thels of thermal wijan city. Air flwitness attenuaith convex geoedges which

Also other anality, changes inmperature in

g the studied mnality of the foed factors havcomfort. Resuare greater innvex and tall

s of thermal weBut in the fore satisfaction leevel. Role of different clima

e of evaluating and large arena more efficias it prevent t

s the expenses building, too. s that the geomrge spans in vehermal comfort damental relatiom of the ceilin

nd humid climeases in respect height, the functsupplement the

with high are convex shaped

udies we can aants and trees i

exhibitions anal ventilationtion of fans died on furtherdischarge the genhouse during also subject

ing can impacre like a con

nt forms of buie airflow rate inwelfare of peoflow takes placation of speed ometries and tis quite opp

lyzed factors in the air circuthe exhibitionmodels. These

orms in the stuve a direct imults indicated thn respect with

geometry wouelfare for the vrms with low evel of the visthe geometry

ates is considerform of the ce

nas based on thent design in

the loss of budrelated to the o

metrical shape ofntilators have afor the users ofonship betweenng in ventilato

mates, as the lto its width, or tion of the space thermal com

cs have a mod forms in the

lso: 1. reevaluain simulating thand the alteratn of the exhibit

and their imr studies. 3. Thgases that are g the winter of further stu

t the airflow ntainer. The ildings based n the interior

ople based on e in a variety in the center

the growth in osite in the including the

ulation speed, n space have e differences

udied climate. mpact on the hat the forms their widths,

uld lead to a visitors in the

heights and sitors reaches in providing

red impactful eilings for the he climate in the terms of get, time and operation and

f the covering a bold role in f the space. n the type of ors with large

length of the in the case of

ce to naturally mfort indexes

ore efficiency moderate and

ate the issues he interior of tion that are tion by trees.

mpact on the he importance

produced by with natural

udies on this


35

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Appendix: A Nomenclatures

Interior temperature of greenhouse (c) Tc Area of the greenhouse roofing (m2) Ac

Exterior temperature Ti Area of the greenhouse roof covers (m2) Af

Temperature of greenhouse floor ( °c) Tf Specific heat capacity.(m) d Equivalent radiant temperature (°c) Tsky Specific heat capacity (Jkg-1°c-1) Cpa

Heat loss factor of the greenhouse cover.(W·m-2·c-1) u Gravity (m3kg-1s-2) g Wind Speed outside of the greenhouse (ms-1) v Height of the greenhouse crest (m) h Greenhouse air volume (m3) vg Heat transfer coefficient Between the shell and the air outside

(wm-2°c-1)

hc-o

Width of the Greenhouse w Heat transfer coefficient from fluid (wm-2°c-1) hf

Viscosity of molecules (m 2/s) µ Enthalpy of interior humidity( Jkg-1) Ii

Stefan–Boltzmann constant σ Enthalpy of exterior greenhouse humidity (Jkg-1) I.

Level of air movement (m 3/s) Q Thermal conduction (W·K-1·m-1) k Surrounded air volume (m 3) V Length of the greenhouse (m) l Density (Kg/m 3) ρ Greenhouse ventilation level (kgs-1) ma

Time (s) t Air exchange rates for an hour (h-1) Na

Air exhaust time (s) Texhaust Pressure (pa) P Average Air exhaust (s) Tage Temperature transfer rate between the covers and the outside Qc-o

Turbulent Prandtl number from Turbulence kinetic energy kα Turbulent kinetic energy Due to floating property (m2/s-2) Gb

Turbulent Prandtl number for energy dissipation rates kα Turbulent kinetic energy according to the average gradient per hour (m2/s-2)

Gk

Supply Sɸ

Components of the air speed UV W

Amount of air movement ɸAppendix: B Abbreviations

Computational Fluid DynamicCFD

Finite Volume MethodFVM

Local Mean AgeLMA

Cubic Feet per MinuteCFM

Air Change per HourACH

Partial differential equationPDE

Predicted Percentage of Dissatisfied PeoplePPD

Mean Radiant Temperature MRT Predicted Mean Vote PMV


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