Types of Green Houses

Types of Green Houses

1. BIRSA AGRICULTURAL UNIVERSITY
Protected Cultivation and Secondary
Agriculture
LECTURE 5: Types of Green Houses
BY
DR. PRAMOD RAI
DEPARTMENT OF AGRICULTURAL ENGINEERIN

2. Types of GH
ClassificationofGHsystems
ClassificationbasedonGHworking
principles
GHtypebasedoncostofconstructionor
technology
GHTypeBasedonConstruction
GHTypeBasedonCoveringMaterial
GHTypeBasedonShape

3. Classification of GH systems
FreestandingGH:Separatefromother
buildingsconsistingofsidewalls,endwalls,and
aroof
SolariumorattachedGH:Attachedtoa
house

4. Greenhouse GH systems
Solarium
Crop dryingCrop production
Heating
of GH
Cooling
of GH
Heating Ventilated GH
Space heating Solar energy
collector
Active
Solar GH
drier
Natural Forced
Ventilation Evaporative
cooling
Buried pipe Movable insulation
North wall Ground air
collector
Natural Forced Natural Forced
Water tank
Heating
and
cooling
of GH
Free Standing

5. Classification of GH based on working principles
PassiveGH
Donotrequiremechanicalenergyformovingfluidsfortheir
operation.Fluids&energymovebyvirtueoftemperature
gradientsestablishedbytheabsorptionofradiation.
TheGHactacollector,astheglazedarea,wallsandroofsare
usedforcollecting,storinganddistributionofsolarenergyinthe
GHbythenaturalprocessesofconduction,convection&
radiation.
Itdependonarchitecturaldesigntomaximizesolargainin
wintertoreduceheatingandminimizetheminsummertoreduce
cooling.
ActiveGH
Thereisanexternalthermalenergyavailableeitherfrom
conventionalfuelorsolarenergythroughacollectorpanelisfed
insidetheGH.
TheseGHsusefan&pumpswiththehelpofmechanicalenergy
tomovetheworkingfluidinthesystem.

6. Greenhouse
Passive
Greenhouse
Active
Greenhouse
Heating Cooling Heating Cooling
Water
Storage
Rock-bed
Storage
North Wall
Munching
Phase
Changing
Material
Movable
Insulation
Natural
Ventilation
Shading
Warm
Water
Soil Storage
Buried Pipes
Rock Piles
Forced
Ventilation
Evaporative
Earth Air
Tunnel
Misting

7. GH type 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

8. Structu
re &
Glazing
Environment Culture
method
Expected
yieldof
tomato
(kg/m
2
/yr)
Investme
nt cost
(Rs./m
2
)
Canopy Root
Bambo
o or
Wood
Single
layer
Passive
cooling
(roof and
side wall
vents)
No
heating
Soil
Drip
irrigation
with
manual
control
Med-
high
wire
10 –20300-500
Low cost or low tech GH

9. Structure
&
Glazing
Environment Culture
method
Expected
yield of
tomato
(kg/m
2
/yr)
Investmen
t cost
(Rs./m
2
)
Canopy Root
Steel
frame
Double
PE film or
rigid
plastic
Passive/A
ctive
cooling
(vents+pa
d/fan)
With or
without
air heating
Basic
level of
computer
control
Soil or
soiless
substrate
Drip
irrigation
Some
control
High
wire
culture
Longer
season
Usually
computer
ized
fertigatio
n
25 –50500 –1500
Medium cost or medium tech GH

10. Structure
&
Glazing
Environment Culture
method
Expected
yield of
tomato
(kg/m
2
/yr)
Investment
cost
(Rs./m
2
)
Canopy Root
Steel or
Aluminu
m frame
Glass,
polyethyle
ne or
Polycarbo
nate
Forced
ventilation
+
evaporativ
e cooling +
hot water
pipe
heating +
CO
2
enrichment
+ shading
(light) +
energy
blanket
Soilless
substrate
Drip
irrigation
with full
automated
control
(EC
control
according
to light
intensity)
High wire
culture
Fully
computeri
zed
fertigation
Recirculat
ion
Hydroponi
cs
50 –75
More than
1500
High cost or high tech GH

11. GH Type Based on Construction
Wooden framed structure
Pipe framed structure
Truss framed structure

12. Wooden framed structure
Beinghygroscopic,itisgenerallytreatedforprotectionfrom
highmoisture,termites&paintedforbetterlightcondition
insidetheGH.
Cromatedcopperarsenate(CCA)andammoniacalcopper
arsenate(ACA)isusedforprotectionfrommoisture&
termites.
Bamboo/Timberavailablelocallywithgoodstrength,
durabilityandmachinabilityalsocanbeused.
TheGHwithspanlessthan6mareused.

13. Pipe framed structure
Usedwhentheclearspanisaround12m.
Thesideposts,columns,crosstiesand
purlinsareconstructedusingpipes.
Thetrussesarenotused.

14. Truss framed structure
TheGHspanisgreaterthanorequalto15m.
Flatsteel,tubularsteelorangularironisusedtoforma
truss.
Most glass houses use truss frames.
Struts support members under compression and chords
support members under tension.
AngleironpurlinsrunningthroughoutthelengthofGH
areboltedtoeachtruss.
(Source: www.angrau.ac.in, www.gothicarchgreenhouses.com , www.redpath.co.nz )

15. GH Type Based on Covering Material
Glass GH
Plastic film GH
Rigid Panel GH
IthasdirectinfluenceontheGHeffect
andinsideenvironment.
Thetypesofframes&methodoffixing
alsovarieswiththecoveringmaterial.

16. Glass GH
Themaintenanceofglassishigh,thoughitprovidegood
transmissionovertime.
Transmit84-87%ofvisiblelight,butitreducedto70-75%
duetosupportingstructureprovidedtosupportit.
Availableindifferentgrades,weights,andsized.
Requiremorestructuralsupportthanothers.
Higherairinfiltrationrate,leadstolowerinteriorhumidity
andbetterdiseaseprevention.
(source: www.gothicarchgreenhouses.com)

17. Plastic GH
Ithasasmuchas90%transmittivity.
Itshigherstrength&lowcosthavemadeitmost
popularreplacementofglass.
Polyethylene,polyesterandpolyvinylchloride
areused.
ThecostofheatingislesscomparedtoglassGH.
Shortlifespan&UVinhibitorsincreaseslife
spanuptoaverageof3years.
Availableinvariouswidths,lengthsand
thickness.
Canproducecondensation

18. Rigid Panel GH
Fibreglass-reinforcedplastic(FRP)
Acrylicsheet
Polycarbonatesheet

19. Fibre glass-reinforced plastic (FRP)
Theseplasticsconsistofpolyesterresins,glass
fibersandcanhaveminoramountsofotherresins,
stabilizersetc.
Itisavailableinflatandcorrugatedconfigurations.
CorrugatedpanelsarecommonlyusedforGH
roofs,asitsshapelendsstrengthandrigiditytothe
panels.
Flatpanelsareusuallyusedforsidewalls,
windows,andvents.
Susceptibletoultraviolet,dust&pollution
degradation,mustuseclearpanels.
Highlyflammable,thereforeinsuranceratesmaybe
higherthanothercoverings.

21. Acrylic sheet
Lightweightincomparisontoglasspanel.
Flammable
Itisavailableinthickorthindoublewall
extrudedsheets.
Itisalessexpensivealternativeto
polycarbonate.
Itisastransparentasthefinestopticalglass.
Ithasahighexpansionandcontraction
coefficient.
Moreresistanttobreakagethanglass,butless
thanpolycarbonate.
Attachmentsimilartopolycarbonate.

23. Polycarbonate sheet
Most widely used.
Less heat is lost than glass panel.
UV protectantadded to most products.
Available in corrugated, double wall, triple
wall.
Widely used to glaze end walls and gables
of Quonset houses.
Easily retrofitted to glass houses
High impact resistance
Not considered flammable

25. Characteristics of GH cladding material
[a]
TypeofPlastic Advantages Disadvantages DurabilityLightTransmission
Anti-drop UV-
stabilized
Wideandofvariable
sizes, relatively
inexpensive,UV-
resistant
Expensive, requires
maintenanceandcanpuncture
andteareasily
Fair,2-3
years
Verygoodwhenkept
clean,89%to91%
UV-stabilized
PolyethyleneFilm
Wideandofvariable
sizes, relatively
inexpensive,UV-
resistant
Requiresmaintenanceandcan
punctureandteareasily
Fair,2-3
years
Verygoodwhenkept
clean,>90%
PolyethyleneFilm
Non-Stabilized
Inexpensive,wideand
ofvariablesizes
Requiresmaintenanceandcan
punctureandteareasily
Poor,1yearVerygoodwhenkept
clean,>90%
Acrylic Weather-resistantand
break-resistant
Flammable,expensive,easily
scratched,notapplicableto
tropicalorwarmclimates
Verygood,
>5years
Verygood,>90%
Polycarbonate Impact-resistant,
flexible,thinand
relativelyinexpensive
Easilyscratched,reducedlight
transmissionwithageingand
expands/contracts, not
applicabletotropicalorwarm
climates
Good, 5
years
Fairtogood,80%to
90%
Fiberglass Impact-resistant,
moderatelypricesand
easilycut
Forsmallergreenhouses,
expensiveinlargerscale,
reducedlighttransmission
withageing,collectsdust
easily
Verygood,
>5years
Fair,80%
PolyvinylChloride
(PVC)andEthylene-
vinylacetate(EVA)
film
AllowsUVthrough,
heat retention
properties
Notapplicabletotropicalor
warmclimates,shortlifespan
forrigidcladding
Fair,<5
years
Verygoodwhenkept
clean,87%to91%
[a]
Adapted from Von Zabeltitzand Baudoin(2005), Von Zabeltitz(2011) and DeGanneset al. (2014).

26. GH Type Based on Shape
SolariumorattachedGH:Connectedtoahouse
Lean-to-GH,attachedeven-spanGH,window-mounted
GH
FreestandingGH:Separatefromotherbuildings
consistingofsidewalls,endwalls,andaroof
Quonset/hoop
ModifiedQuonset/arch
GableevenspanGH
GableunevenspanGH
ConnectedGH:SeveralGHjoinedtogether
Sawtoothtype
Ridge&furrowtypeorgutterconnected
Venlo-DutchHouses
Barrelvault

27. Solarium or attached GH
Placed against an existing wall
Common for institutional or hobby greenhouses
Typicallyfacingsouth
(source: www.howtobuild-a-greenhouse.org, www.small-greenhouses.com,)

28. Quonset/hoop GH
Curveroofswithoutsidewalls.
Thecoveringmaterialusedispolyethylene.
LessexpensivethanthegutterconnectedGH.
(source: www.gothicarchgreenhouses.com )

29. Modified Quonset/arch GH
Asemi-circledesignelevatedbysidewalls.
Viningtomatoes,cucumbers,peppers,etc.canbe
grown.

30. Gable even span GH
Twoslopesofequalpitchandwidth
Mostcommonconfiguration
UsedfortheGHofsmallsizeandisconstructed
onlevelground.

31. Gable uneven span GH
Constructed on hilly terrain
Roofs of unequal width and pitch
Good for high latitude sites

32. Saw tooth type
GHsimilartoridgeandfurrowtypeGHexcept
that,thereisprovisionfornaturalventilation.
Upperportionsofroofareventedtotake
advantageofnaturalventilation
(Source: www.netafim.com )

33. Ridge & furrow or gutter connected
Multiple A-frame spans connected along the eaves
The eave serves as furrow or gutter to carry rain
and melted snow away
Singlelargeinterior,consolidationofinterior
spacereduceslabour,lowersthecostof
automation,improvespersonalmanagementetc.
(Source: www.nafis.go.ke )

34. Greenhouse Structural Components
Basic structural components of a greenhouse: A) rafter, B)
end wall, C) side post, D) side wall, E) purlin.

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