PLANNING AND DESIGN OF GREENHOUSE�

PLANNING AND DESIGN OF GREENHOUSE�

1. BIRSA AGRICULTURAL UNIVERSITY
Protected Cultivation and Secondary
Agriculture
LECTURE 7: PLANNING AND DESIGN OF GREENHOUSE
BY
DR. PRAMOD RAI
DEPARTMENT OF AGRICULTURAL ENGINEERING

2. TheGHdesignmustdealwiththelocaloutdoor
conditions,like:
Minimum, maximum & average temperature,
Humidity,
Solar radiation,
Clearness of the sky (clouds),
Precipitation (rain, hail and snow),
Average wind speed & wind direction.
Greenhouse Design

3. Environment inside GH
Natural climate [outside]
+
Greenhouse design
+
Management
creates
Greenhouse climate
[inside]
Controllable
No
Yes
Yes

4. Greenhouse Design
Structure
Cover
Environmental control
systems
Affects Environment
Yes
Yes
Yes

5. Aerial
Cooling Heating
CO
2 VPD
Root Zone
Nutrition
Oxygen
Environmental Control

6. GH design based on cost of construction or
technology
Low cost or low tech GH
Medium cost or medium tech GH
High cost or hi-tech GH

7. Planning and Design of Greenhouse
1. Site Selection and Layout
2. Design Load
3. Construction
4. Safety
5. Utilities

8. 1. Site Selection and Layout
Recommendationsforlayout,designand
constructionofGHstructures(IS14462:1997)

9. WhileselectingthesiteforconstructionofaGH,followingpoints
shouldbeconsideredfortheoptimumgrowth&developmentof
plant:
Thesiteshouldbefreefromshadow.
Thesiteshouldbeatahigherlevelthanthesurroundinglandwith
adequatedrainagefacility.
Availabilityofgoodqualityirrigationwaterandelectricitytorunthe
fan&padcoolingsystem.
pHoftheirrigationwatershouldbeintherangeof5.5to7.0andEC
between0.1to0.3mS/cm.
pHofthesoilshouldbeintherangeof5.5to6.5andECbetween
0.5to0.7mS/cmrespectively.
Proximitytomotorableroadtotakeadvantagesofmarketforinputs
supply&saleproceeds.
Soilneedtobechangedorsterilizedafterevery3to4years
preferablytoavoidbuiltupofsoilpathogens.Alternatively,artificial
mediacanbeanoptionforcultivation.
1.1 Site selection

10. Locationwithrespecttohighwaysshallbe
considered.
Locationonnearahighwayandresidentialarea
mayincreasebusinessforaretailoperation.
1.2 Location

11. Thefollowingpointsshouldbeconsideredin
developingalayoutforGHstructure:
LocatetheheadhousetothenorthoftheGHtoreduce
shading;
Locatewindbreaksatleast30mawaytothesideofthe
prevailingwinterwindstoreduceenergyconsumption;
Separatesupplier&customertraffic;
Provideforconvenientconsumerparking;
Locateandscreenanyresidencetoinsureprivacy;
Placetheoutdoorstorageareawhereitisconvenientto
accessformaterialsdeliveryandmovementtothe
workarea
Locatetheretailsalesareatokeepcustomersaway
fromtheproductionareatoreducechancesfordisease
introductionandpreventinterruptionofworkroutines
1.3 Site layout

12. Fig. 1: Plan layout of a GH along with other support facilities

13. Correctorientationcanprovidegoodenvironmental
conditionsinsidetheGH.Followingpointsshouldbe
consideredwhiledecidingtheorientationofaGH
dependinguponlightintensityanddirection&velocity
ofwind.
OrientationofthesinglespanGHshouldbedirected
towardsEast-West.
North-Southincaseofmulti-spanfortakingadvantage
ofavailablesun-shine.
GuttershouldbemadeinNorth-Southdirectionin
multispanGH.
Slopealongtheguttershouldnotbemorethan2%.
Windbreaks,shouldbeplacedatleast30metersaway
onNorth-WestsideoftheGH.
1.4 Orientation

14. Aheadhouseshouldbebuilttohousetheoffice,utilities,workareas,
employeeareas,storage,anddispatch.
Thisvalueshouldbeadjusteddependingontheindoorstorageneeded
andtheamountofmechanizationused.
Agoodheadhouselayouthelpsthesystemoperatesmoothlyand
efficiently.Materialsflowshouldbesuchthatthereisminimumof
handlingorcrosstrafficinmovingthecomponentsthroughthesystem.
Theamountofspaceneededisdeterminedbythetypeofoperation,kind
ofmediabeingused,andthelocalclimate.Calculatespacerequirements
basedontheamountthatisneededforonecroporaspecifictimeperiod.
Locatethestorageareaforbulkmaterialsandtruckloadswherethereis
goodaccessbyallweatherroad.
Thestorageshouldbelocatedclosetotheworkareatoreducehandling
timeandcosts.Providedrainageinthestoragearea.
Materialsstoredwithoutcovershoulddrainquickly,provideapaved
areaforhandlingwithabucketloaderorforklift.
Aclearspanstoragebuildingallowsfreedomofmovementfortractors
andtrucksandallowsarrangementofequipmenttobeeasilychanged.
1.5 Head house and storage facilities

15. Table 1: Sizing the Headhouse
GH Size (m
2
Approximate HeadhouseArea
Needed Per 100 m
2
of GH Area
m
2
1000 to 3999 14
4000 to 7999 9
Over 8000 7

16. Thechoicebetweenproductiononthefloororonthebenches
dependsonthecropandtheproductionschedule.
Benchesareusuallyprovidedforpotplantproduction.Bedding
plantsaregenerallygrownonthefloor.Beds,eithergroundorraised
areneededforcutflowers.
Benchesmaybefabricatedofwood,metal,orplasticwithaeither
solidormeshbottom.
Benchesshouldbeplacedataconvenientheightabovethefloor,
usually500to1000mm.
Benchesimprovelabourefficiency,permitmoreeffectivedisplay
andinspection,andassistaircirculation.
BencharrangementdependsondimensionsoftheGH,walkways&
doorsandonmaterialshandling&heatingsystemtypeandlocation.
Totalaislespaceshouldbelessthat25percentofthetotalarea.
Longitudinalarrangementswithbenchesextendingthelengthofthe
housepermitscontinuousrunsofwaterlines,heatpipes,andplant
supportsystems.
1.6 Interior layout

17. Fig. 3: Cross bedding layout of GH beds
Fig. 4: Longitudinal layout of GH beds
Fig. 2: Peninsula arrangement of GH beds/benches

18. 2. Design Load

19. AlIfixedservicesequipmentsuchasheating,
ventilating,aircirculation,electrical,lighting,
wateringandenergyconservationblanketsshould
beincludedifsupportedbystructuralmembers.
Longtermcropssuchastomatoes&cucumbers
supportedbythestructurearealsoconsideredas
deadloads.
2.1 Dead Load

20. 2.2 Live Load
Liveloadsaretemporaryloadsandshallincludethe
massofrepaircrewsandhangingplants.
TheGHshouldbedesignedastoresistthesnowload.
Inareaofsnow,aminimumdistanceof3.0mshouldbe
providedbetweenGHtoallowforsnowaccumulation
andtopreventsidewallcrushingfromsnowslidingoff
theroof.
ThesnowloadofGHstructuresshallbeestimatedas
prescribedinIS875(Part4).
2.3 Snow Load

21. 2.4 Wind Load
TheGHshouldbedesignedtoresistthewindload.
ThewindloadoftheGHstructuresshallbeestimatedas
prescribedinIS875(Part3).
SincethedeadweightofmostGHstructuresisvery
small,specialattentionshouldbegiventoensurethat
enoughgroundmaybetheretoresisttheupwardlift
forcecreatedbythewind.
TheminimumdesignloadsfortheGH,structures
mainframesisgiveninTable2andmaybeusedfor
referenceonly.
ActualdesignvaluesshouldbecalculatedforeachGH
structures.

22. Table 2: Minimum Design Loads for GH Mainframes
Load Description
Minimum
Value
N/m
2
Dead:
Pipe frame, polyethylene cover
truss frame, lapped glass
supported crops-tomatoes, cucumbers, etc.
100
250
200
Live: workers, repair materials 250
Snow: 10
o
C minimum GH temperature 750
Wind: load acts perpendicular to surfaces500

23. 3. Construction

24. PierfoundationmaybeadequateforprimaryGHframe,consistingof
hoopsspacedonemeterormore.Acurtainwallcanbeusedtoclose
theareabetweenthepiers.Ifprimaryframemembersarespacedless
than1.2m,acontinuousmasonryorpouredconcretewallshouldbe
used.
Thefootingshouldbesetbelowfrostlevelortoaminimumdepthof
600mmbelowthegroundsurfacewhicheverisgreater.ConsultSP7
buildingcodeforlocalrequirements.
Itshouldrestonlevel,undisturbedsoil,oradequatelycompactedfill.
Individualpierfootingsshouldbesizedtofittheloadandsoil
conditions.
Thepiermaybeofreinforcedconcrete,galvanizedsteel,treated
wood,orconcretemasonry.Thewallbetweengalvanizedpierscanbe
pouredorprecastconcrete,masonry,fibrereinforcedcementpanels,
aluminumcladinsulatingboard,oranymoistureanddecayresistant
material.
Acontinuousfoundationwallshouldbesetonapouredconcrete
footing.Thewallcanbeconcreteormasonry.
A150mmwallisusuallysufficientforbuildingspansupto7.5m.
Usea200mmwallforwiderbuildingspans.
3.1 Foundations

25. Fig. 5: Temporary GH foundation
Fig. 6: Tubing DR pipe foundation

26. Fig. 8: Concrete masonry wall on
poured concrete footing
Fig. 7: Concrete piper foundation

27. Table 3:Pier Footing Diameters for Average Soil for Design
Gravity Loads (Check for Uplift due to Wind)
GH
Span
(m)
Pier Spacing (m)
1.2 1.8 2.4 3.0 3.7 4.6
Pier dia (mm)
6.1150 230 300 300 300 380
7.3230 300 300 300 380 380
8.5230 300 300 380 380 460
9.5230 300 300 380 380 460
11.0230 300 380 380 460 **
12.2300 300 380 380 460 **
14.0300 380 380 460 460 **
18.3300 460 460 460 ** **
* 122050 N/m
2
average bearing capacity.
** Requires special design.

28. Gravel,peastoneandtraprockmakeagoodfloor
material.Athicknessof150to200mmisneededfor
drainageandweedcontrol.
Whereahard,smoothsurfaceisdesireda50to75
mmthicknessofporousconcretemaybeused.Thisis
madefromuniformsizedaggregateandacement
waterpaste.
Aislesandheavytrafficareasshouldbeconcrete.
Thicknessdependsonthetrafficloadbutusually75
to100mmissufficient.
Concretewalksshouldhaveabroomfinishforsafety.
Floorsshouldslopetoassuresurfacedrainageandbe
sufficientlyeventopreventpuddling.
3.2 Floors

29. Wood,steel,aluminium,andreinforcedconcretemaybeusedtobuild
framesforGH.
Someframesusecombinationsofthematerials.Woodmaybepaintedor
otherwisepreservedforprotectionagainstdecayandalsotoimprovelight
conditionswithinthebuildings.
Preservativesshallbeusedtoprotectanywoodincontactwithsoilagainst
decaybuttheymustbefreeofchemicalsthataretoxictoplantsor
humans.HeartwoodhasnaturaldecayresistanceWoodframesinclude
postbeamandraftersystems,postsandtrusses,gluedlaminatedarchesand
rigidframes.
Steelandaluminiumareusedforposts,beams,girts,purlins,trusses,and
arches.Bothmaterialsshallbeprotectedfromdirectcontactwithground
topreventcorrosion.Whitepaintoneithermaterialwillimprovethelight
reflectioninaGHstructure.
Therateofheatlossthroughsteeloraluminiumismuchhigherthan
throughwood,sometalframesmayneedspecialinsulation.Toavoidsuch
heatlossthroughsteeloraluminium,compositematerialsaresometimes
used,suchasatrussedbeamofwoodandsteeloramembermadeof
fibreglassreinforcedplasticmaybeused.
OtherdetailsforGHFrames(Lecture5)
3.3 Frames

30. SolariumorattachedGH:Connectedtoahouse
Lean-to-GH,attachedeven-spanGH,window-mountedGH
FreestandingGH:Separatefromotherbuildingsconsisting
ofsidewalls,endwalls,andaroof
Quonset/hoop
ModifiedQuonset/arch
GableevenspanGH
GableunevenspanGH
ConnectedGH:SeveralGHjoinedtogether
Sawtoothtype
Ridge&furrowtypeorgutterconnected
Venlo-DutchHouses
Barrelvault
3.4 Shape of Structure
Other details for Shape of Structure (Lecture 5)

31. 3.5 Cladding materials
Glass GH
Plastic film GH
Rigid Panel GH
IS 15827:2009 Plastic films for GH-Specification
Other details for GH cladding materials (Lecture 5)

32. Transmission for global radiation (UV and PAR)
Transmission for heat radiation (NIR and FIR)
Insulating effect
Sensitivity to ageing (mainly UV degradation)
Permeability for humidity (water)
Mechanical strength (tensile and impact)
Fire behaviour
Investment costs
Available dimensions
Cladding material properties

33. UV Stabilization
FlexibleGHfilmsareusuallymadefromLDPE,LLDPE,EVAand
similarpolymers.
Intheirnaturalstatethesepolymersdeterioraterapidlywhen
exposedtosunlight.Thesun’sUVlighttransfersitsenergytothe
PEmoleculescausingthemtobecomesoenergizedthattheyare
readilysubjecttooxidation.
Thedegradationprocessisaseriesofreactionsoneleadingto
anotherofwhichtheendproductsarecarbondioxideandwater.
Bigplasticsmanufacturershavebeguntoproducetough,clear,high
PARlighttransmissiongreenhousefilmsusinghinderedaminelight
stabilizers(HALS).
InhibitdegradationofPEpolymersinGHfilmwithoutblocking
UVradiation.Stimulatenaturalbee,bumblebeeandotherinsect
pollination.

34. Diffused film vsClear film
Theincidentlightcanreachtheplantasdirectradiationoras
diffusedradiation.
Diffusedlightdoesnotallowtheshadowformationofthetoplayers
ofleavestopreventessentiallightfromreachingthelowerleaves.
Theendresultisafacilitationofaneffectivedispersionoftotal
lighttothedarkerareasinsidetheplantvolumeenhancing
photosynthesisandhencetheproductionofbiomass.
Breaksunradiationintoamultitudeofrays,optimizingtheeven
spreadoflightwithinGH,which:Increasesefficiencyof
photosynthesiswhencoveredareasofself-shadingandtrailing
plantsreceivelight,decreasesphototropism,decreasespotentialfor
sunburnonbloomsandleaves.

35. UV Blocker
BlockUVsunrays(upto380nm):Causinginsectstolosevisual
abilityinsideGH,preventingviral,fungaldiseasesandcrop
damagecausedbywhiteflies,aphids,redspiders,leafminers,
thripsandotherinsects,resultinginsubstantialdecreasein
dependence,onanduseofagriculturalchemicals,contributingto
IntegratedPestManagement(IPM)programs.Diseasecontrol
filmsshouldnotbeusedinGHrequiringinsectpollination
Blackening(orpetaldiscoloration)ofredrosesisamajorproblem
fortherosegrowers.ThisphenomenoniscausedbytheUV
radiationactingtogetherwithlowtemperatures.AcropunderUV
blockerfilmdoesnotexperienceblackeningofrosepetals.

36. Infrared (IR) Additive
Minimizetemperaturefluctuation:
Duringtheday,slightlydecreasestemperatureinsideGHby
blockingnearinfraredradiation(NIR:700-3000nm).Itisthepart
ofthesolarspectralthatishardlyusedbytheplantsfor
photosynthesis;itismostlysubstitutedintoheat(sensibleand
latent)intheGH.Thiscanbeanadvantageinacountrywitha
colderclimateandadisadvantageinaGHlocatedinwarmcountry.
Duringthenight,increasestemperatureinsideGH,bycreatinga
barriertofarinfraredradiation(FIR:3000-100000nm)reflectedby
thesoil.Itisnotcausedbydirectsunradiation,butitisheat
radiationtransmittedbyeachheatbodyinandontheGH.This
radiationisveryimportantinGH;sinceitcausesapartofthe
greenhouseeffect.

37. Anti-Dust Additive
Facilitatetheremovalofdust,soilanddirt
stuckontheouterGHsurfacewithrainora
simplewash.
Preventdecreaseintheamountoflight
transmittedthroughtheGHcover.
Anantidustlayerisalwaysontheupperside
oftheplastic.Itisveryimportanttonotethat
antidustsidemustbefacingoutside.

38. 3.6 Roof Slope
RoofslopeisanimportantparameterinGHdesign.
Themaximumamountoflightenergytransmittedoccurswhenthe
glazingsurfaceisperpendiculartothesolarrays.
Transmissionofsolarradiantenergyisdeterminedbytheangleat
whichsolarraysstriketheGHsurface.
Figure 9: The effect of angle of incidence on transmission of solar radiant energy through GH glass

39. 3.7 Influence of Interior GH Components and Systems
Withtheadventofthermalscreens,supplementallightingandother
GHhandlingsystemsalongwithtraditionaloverheadheating
systemsconcernhasbeenexpressedforobstructionofPARlighting
whichiscausedbytheseoverheadmountedcomponentsofthe
growingsystem.
Underbenchheatingandin-floorheatingsystemshavereducedthe
numberofoverheadheatingpipesnecessarytomeetthedemand
load.
Thermalscreenswhichareinstalledandmoveguttertoguttercan
reduceshadingbecausethethermalscreensharestheshadow
patternwiththeshadowcausedbythestructuralgutteranddoesnot
addanadditionalshadowwhichiscausedbythesystemwhich
movesfromtrusstotruss.
Therehasbeenanattempttoreducethesizeofsupplemental
lightingfixturestoreducetheshadowpatternstheyproduce.The
growermustbeconcernedwiththeadoptionofnewpracticeswhich
addsignificantoverheadcomponents.

40. 3.8 Size
ThesizeoftheGHneedstobeselectedbasedon
availabilityoftheland.
ThecostmayvarydependinguponthetypesofGHand
numberofsupplierspresentintheregion.
DependinguponthemarketaccessandexperienceofGH
cultivation,itissuggestedtostartwithanaturally
ventilatedGHhavingminimumsizeof100sqmasit
wouldrequirelessinitialcapitalinvestmentalongwith
operationalexpenditure.
However,experiencedfarmers/entrepreneursmaydecide
togoforlargersizeGHdependingontheirscaleof
operationandprojectcosts.

41. 3.9 Height
HeightisoneofthemostimportantaspectsofGHdesign
anditdirectlyimpactsnaturalventilation,stabilityofthe
internalenvironmentandcropmanagement.
TheidealcentreheightofnaturallyventilatedsmallGH
(upto250sqm)shouldbeintherangeof3.5mto4.5m
and5.5mto6.5mincaseoflargesizeGH.
Theside/gutterheightshouldbeinbetween2.5mto3m
and4.5mto5mforsmallandlargesizeGHrespectively.
BothtypesofGHcanbemadeinsingleormulti-span
structures.
Amulti-spanGHcanbeconstructedforanareamorethan
200sqmandiseconomicalintermsofconstruction
material&requiredcontrol/monitoringequipments.
HeightoftheGHhavingfan&padcoolingsystemshould
beslightlylesserthanthenaturallyventilatedgreenhouse
andinanycasenotbemorethan5.5m.

42. 4. Safety

43. 4.1 Fire Safety
Firesafetyisimportantinselection&useofglazing
materials.
Flammabilityofplasticmaterialswhenexposedtoan
ignitingsourceshallbeasprescribedinIS11731(Part1
and2).
4.2 Mechanical Safety
Thereshallnotbeanyprojectionsofsharppointsor
edgeswhichmaycausecuts/lacerations.
Adequateguardingagainstentrapmentoflimbsin
movingandstationaryequipmentshallbeprovided.

44. 4.3 Electrical Safety
Thereshallbenobreakdownofinsulationandcurrent
leakageinfromelectricalfittingsinsidetheGH.
GHframeshallbeprotectedfromcontactwithparts
normallyathazardousvoltage.
4.4 Chemical Safety
InsidetheGHthereshallhefullprotectionagainst
potentialinjuryordamagetohealthresultingfrom
inhalation,ingestationorcontactwithharmful
chemicalagents.

45. 5. Utilities

46. 5.1 Electricity
Anadequateelectricalsupplyanddistributionsystemshouldbe
providedtoservetheenvironmentcontrol&mechanizationneeds
oftheGH.
Todeterminethesizeoftheservices,thesizeandthenumberof
motorsandotherelectricalcomponentsshouldbeknown.
Provisionsshouldbemadeforanalarmsystemtoindicatewhena
powerfailurehasoccurredoranenvironmentcontrolsystemhas
failed.
Anauxiliarygeneratingsystemshouldbeavailableandinstalled
withthepropertransferswitchtopreventfeedbackofpowertothe
utilitylines.
Utilitylinesshouldbeburiedtoimproveappearance,avoiddamage,
andreducehazards.
Electric,phone,andfuellinesshouldbeburiedatleast500mm
deeptoavoiddamagefromsurfacetraffic.
Locationoftheutilitylinesshouldberecordedonamapforfuture
reference.
FordistributionsystemwithintheGHstructure,theNational
ElectricalCodemaybetakeninaccount.

47. Table 4: Electrical Power Requirement for GH of different
size (Chandra, 1992)
GH size (m
2
)(amp/volts)Electrical power
requirement
500 60/240 15
500 –2000 100/240 24
2000 –3000 150/240 36
3000 –4000 200/240 48
4000 –8000 400/240 96
8000 –12000 600/240 145

48. 5.2 Watering
Theamountofwaterrequirmentdependsonthewaterrequirement
ofthecultivationmedium,areatobeirrigated,cropgrown,weather
conditionsandwhethertheheatingand/orventilatingsystemis
operating.
DetailsforirrigationsystemsinGH(Lecture9)
Table 5:Estimated Maximum Daily Water Requirements
Crop
Water Required
litres/m
2
Bench crops 16.0
Bedding plants 20.0
Pot plants 20.0
Chrysanthenum 41.0
Roses, tomatoes 29.0

49. ThewatersystemfortheGHshouldhavethecapacityto
supplythetotaldailyneedsina6hourapplicationperiod.
Thisallowstheplantstobewateredduringthemorningand
earlyafternoonandwithtimeforthefoliagetodrybefore
sunset.
Groundwaterisusuallythemostreliablesourceofwater.Itis
availablefromdrilledwells,dugwells,etc.
Surfacewaterponds,lakesandstreamsmayalsobeused,but
precautionsshallbetakentoinsureagainstcontamination
injurioustotheplants.
Irrigationwatermaycontainimpuritiesthatadverselyaffect
thegrowthoftheplants.Therefore,qualityofthewatershall
beensuredbeforeirrigation.
Microirrigationsystemisthemostsuitablemethodfor
irrigationtotheGHcrops.Thequalityofirrigationwatershall
conformtoIS11624.

50. 5.3 Climate Control System in GH
CoolingoftheGHisnecessarywherevertheoutsidetemperaturegoes
beyond30°Candalsowhentemperatecropsaretobegrown.
Dependingupontheglazingmaterialandtheventilation,oncetheGH
structuresarecoveredtheinsidetemperaturemaybeatleast5to10°C
higherthantheoutsidetemperature,ifitisnotcooled.Inordertocreate
bettergrowingconditions,itisnecessarytocooltheGHstructures.
Heatingrequiredinplaceswherethewintertemperatureisverylow.
Similarly,inplaceswheretheclimateisextremecoldandwarm,both
coolingandheatingarerequiredathigherelevations,where
temperaturesdonotnormallygoabove30°C,coolingmaynotbe
necessary,onlyprovidingproperventilationwillservethepurpose.
However,theseplacesmayrequireheatingduringwinterforsuccessful
cropproduction.
Heating,ventilatingandthecoolingoftheGHstructuresshallbe
doneasprescribedinIS14485:1998.
Detailsforcooling&heatingofGH(Lecture8)

51. Ifyouhaveanyquestion/suggestion
Mailme:[email protected]
ContactmeonWhatsApp:8986644713