This document provides information on greenhouse types, design, and precautions. It discusses the principles of greenhouses, their uses for growing plants, and classifications based on cost. It describes different greenhouse shapes and frames materials. The document covers natural ventilation systems, glazing materials like glass and polyethylene films, and considerations for soil, water, and seeds. It provides details on greenhouse construction, orientation, sizing, and maintenance.

1. GREENHOUSE TYPES, DESIGN
AND PRECAUTIONS
Dr RK Gupta
Professor
Department of Agricultural Engineering
CSK HPKV Palampur

2. Greenhouse Principle
Short wave to long wave to entrap solar energy
1 4 8 10
Ultra violet Visible Infra red
Suppressed growth Normal growth Long and
weak plants
X-ray 6x10-13
- 6x10-9
m
UV 6x10-9
- 4x10-7
m
Visible 4x10-7
- 8x10-7
m
Infra red 8x10-7
- 8x10-4
m
TV, Radio 8x10-5
- 8x105
m

3. Photosynthetic & Visible Light
Far-red

5. USES OF GREENHOUSES
• Growing high value vegetables
• Flowers
• Raising nursery of different vegetable crops
• Growing ornamental and medicinal plants

6. Benefits
Round the year production.
Export potential in floriculture
Suitable for adverse climatic conditions
More carbon dioxide available for plants
Higher produce inside the greenhouse

7. CLASSIFICATION OF GREENHOUSES
(COST)
Low cost
Medium cost
High cost

8. CLASSIFICATION OF GREENHOUSES
• Low tunnels
• Without cooling system
• Fan pad system
• Naturally ventilated

9. SHAPES OF GREENHOUSES

12. Soil, seed, water and environment
Environment
o Temperature
o Relative humidity
o Evaporation
o Sunlight
CROP PRODUCTION FACTORS

13. NATURAL VENTILATION

14. NATURAL VENTILATION

15. NATURAL VENTILATION
• Percent of roof space ventilated has increased
over time with design improvements
• Success is very crop specific
• Even fully retractable roof designs are now
available
• Cheaper to operate than active cooling
systems, but construction costs aren’t less
expensive

16. Pad and Fan Cooling
• Available for almost 50 years
• Most common system for summer cooling
• Originally the pad was composed of wood
shreds
• Today it is composed of cellulose
• Exhaust fans are placed on the opposite wall

17. GREENHOUSE FAN PAD SYSTEM

18. WOOD WOOL PAD SYSTEM

19. CELLULOSE COOLING PAD

24. SOIL, WATER AND SEED
• Good quality soil
• Permanent source of water
• Very good quality seed

25. Greenhouse Frameworks
• The greenhouse framework supports the greenhouse
covering material.

26. Greenhouse Models

31. MATERIALS FOR FRAME
• Bamboo
• Wood
• MS Pipes
• GI Pipes (Round and Square)
• Aluminium

32. Greenhouse Frameworks
• The framework should be strong, yet allow the
maximum amount of light to reach the plants.
• It is best if the framework requires little maintenance.
• In high snowfall areas, it is important that the
framework be strong enough to withstand heavy snow
loads.
• It should be capable of withstanding wind loads.

33. Greenhouse glazing
• The covering of the greenhouse is referred to as the
glazing.
• Considerations in choosing a glazing material include
durability, light transmission, cost, and affects on
heating costs.

34. GLAZING MATERIALS
• Glass
• UV Stabilized Polyethylene film
–Plain
–Cross Laminated
–Multi-Layered
• Poly-carbonate (Multi-Layered)

35. UV STABILIZED POLYETHYLENE
•Plain and Multi-Layered
•Available in various thicknesses
• Generally used for GH 200 micron (200 X 10-6
m) thick.
• High transmittance
• Three and five layered also available (Anti dust, anti dip,
etc.)
• Cross-Laminated
•Available in gsm (g/sqm), 150 gsm is generally used.

37. • Greenhouse films are usually made from low
density polyethylene (LDPE), linear low density
polyethylene (LLDPE), ethylene-vinyl acetate
copolymers (EVA) and similar polymers.
• The sun's ultra violet (UV) light transfers its
energy to the polyethylene molecules causing
them to become so energized that they are readily
subject to oxidation.
• The mixing of UV stabilization chemicals at the
time of production is to include components
which will prevent as far as possible the onset of
degradation process
UV STABILIZATION

38. • Several successful stabilizer like hindered
amine light stabilizers (HALS) are used.
• HALS stabilizers protect greenhouse films by
interfering with the propagation of free radicals.
• The HALS additive effectively restricts the
multiplication of these free radicals. So a plastic
film without proper UV stabilization (protection)
will most certainly break down rapidly and leave
the crop exposed.
• Hence all the greenhouse film manufacturers do
stabilize their film against degradation due to
solar radiation.
UV STABILIZATION

39. A cover of 200 microns
thickness can be guaranteed
for three years of service in
the field against
degradation due to UV.
UV STABILIZATION

40. • But a film which contains only a stabilization
package, when used to cover a structure earmarked
for growing crops, will not turn the structure into a
greenhouse.
• At best the structure will be a “shelter”. There are
many other parameters to be considered to call a UV
stabilized polyethylene cover, a greenhouse cover.
• A crucial difference between a simple shelter and a
greenhouse is that a greenhouse must be a heat trap.
In a true greenhouse the escape of heat during the
night is retarded in order to maintain optimal
temperature for as long as possible.
Greenhouse Film

41. • The incident light can reach the plant as “direct”
radiation or as “diffused” radiations which are at
various angles with respect to one another and to a
horizontal plane)
• A diffused film has an advantage over a clear film.
Diffused light does not allow the shadow
formation of the top layers of leaves to prevent
essential light from reaching the lower leaves.
• The end result is a facilitation of an effective
dispersion of total light to the darker areas inside
the plant volume enhancing photosynthesis and
hence the production of biomass.
Diffused film vs Clear film

42. Diffused film vs Clear film

43. • An UV blocker film does not allow the UV radiation (up to 381
nanometers where 400 nanometers marks the end of UV
radiation and the beginning of visible light) to enter the
greenhouse.
• Insects have compound eyes and they can see in the UV range as
well as in the visible domain up to the red section (600-700
nanometers wave length).
• Blocking out the UV blocks significant part of the visible range
of insects. Since the insects can not see many of the signals
which they normally would see outdoors.
• When insects are under UV blocker film, a considerable
decrease in white fly, thrips and other insect activity has been
observed.
• Insects are the carriers and transmitters of many viruses & this
film affects the insect activity it also is called Antivirus film.
UV Blocker (Antivirus film)

44. UV Blocker (Antivirus film)

45. Moisture inside the greenhouse condenses in the
form of large drops of water on the inner side of
the plastic cover, if the plastic is are untreated.
This is undesirable because:
•The drops reflect back to the outer space a large
portion of the incoming light.
•The drops fall on the plants and serve as focal
points for the spread of plant diseases.
•water drops on the film focusing sunlight and
scorching plant leaves
Anti Drip Film

46. Moisture inside the greenhouse condenses in the
form of large drops of water on the inner side of
the plastic cover, if the plastic is are untreated.
This is undesirable because:
•The drops reflect back to the outer space a large
portion of the incoming light.
•The drops fall on the plants and serve as focal
points for the spread of plant diseases.
•water drops on the film focusing sunlight and
scorching plant leaves
Anti Drip Film

47. • Slope of the greenhouse cover on the roof of
the structure (a minimum of 22 degrees to the
horizontal is desirable)
• Proper cladding of the film on the structure
(to avoid folds, waviness and the like)
• The regime of periodical aeration of the
greenhouse
• Height of the greenhouse
Requirement for Anti Drip Film

48. Anti Drip Film

49. An anti drip layer is always on
the inner side of the plastic. It
is very important to note that
when a customer buys an anti
drip film the anti drip side
must be fixed on the inside
facing the plants
Requirement for Anti Drip Film

50. Thermic Film
A thermic film is necessary for the places where the night
temperature drops below the optimum temperature
necessary for the plants.
During the night, infrared additive creates a barrier to far
infrared radiation (FIR: 5,000-20,000 nanometer) which
is being emitted by all objects in the greenhouse.
The net result is a decrease in the rate of temperature
reduction during the night hours in the greenhouse.
If the film cover is not thermic; the radiated energy will
escape to outer space while the enclosed space within the
greenhouse will eventually reach an equilibrium with the
temperature of the air outside the structure.

51. Thermic Film

52. Five Layer Greenhouse sheet

53. Greenhouse Shade Nets
• 30, 50,70 and
90 per cent
shade

54. SITE SELECTION
• Location
– Good Drainage
– No obstructions (Shadow)
– Connected to road
• Orientation
– South facing
• Water
– Permanent source
• Electricity

55. Greenhouse Orientation

56. Long side in EW direction (Facing south)
Greenhouse Orientation

57. X 2X
Greenhouse Orientation

58. • Locate the houses at a distance of 2 times
the height of any object that might cast a
shadow on the greenhouse
• Single ridge below 40 degrees north, run
ridge north and south
Placement of houses for
maximum light

59. SIZE
• Area required for production
• Land available
• Finance available

60. PROCEDURE FOR CONSTRUCTION
•Select the site
•Mark the boundary of greenhouse.
•Make excavation for foundation pipes
•Fix foundation pipes with cement concrete
•Fix all the hoops with foundation pipes
•Construct a ridge line by fastening/welding with hoops.
•Fix the glazing material with thin MS strip/screws
•Secure excess sheet in the channel around GH
•Construct a drainage channel around greenhouse.

61. Layout of Greenhouse
Size 15 x 7 m=105 sq m
15 m
7 m
Make Diagonals Equal

72. Freshly cut bamboo culms of desired length
are immersed with their butt ends in a solution of
Boric acid: Borax (50:50) of about 10%
concentration. The immersion ends should be
done up to a length of about 30 cm of the but-end.
The treatment may last for 8 to 12 days. In this
process, stirring of the solution is demanded on
every day to avoid sedimentation and also add
small amount of the boric acid: Borax mixture to
make up the uptake loss. This treatment is suitable
for using as bamboo as greenhouse poles the end
comes in constant contact with the ground
• Bamboo 3-6 years Old
• Well treated
• Dried In shade

73. SELECTED BAMBOO JOINTS

74. SELECTED BAMBOO JOINTS

75. BAMBOO GREENHOUSE CONSTRUCTION

79. Damaged Due to Wind

80. Greenhouse Frame Maintenance
• Check to make sure that any moving parts
such as greenhouse door hinges are not
accumulating corrosion and if it looks like it
may need oil for lubrication, don't put it off
until later.
• Check for any stress fractures in the
greenhouse frame and also check to make
sure none of the fasteners holding your
greenhouse together have come loose. If
they have come loose, tighten them securely.

81. Greenhouse Frame Maintenance
• If your greenhouse frame is painted wood,
check occasionally for any loose or blistering
paint. If you find the paint is cracking or
blistering, promptly scrape the paint off and
allow to dry completely before sealing and re-
painting the area.
• If your greenhouse frame is constructed of
painted metal and you find rust forming, use a
wire brush to remove any rust and then clean,
prime & paint the affected area.

82. Greenhouse Cover Maintenance
Your greenhouse glazing should also be
maintained regularly.
•Should the glazing become dirty, your plants'
ability to receive sunlight transmission is
reduced considerably. Make sure that cleaning
of your greenhouse glazing is a priority before
winter.
•If your greenhouse is covered with a
greenhouse poly film, make sure to wash it
thoroughly with a mild liquid soap and water

83. Greenhouse Cover Maintenance
Greenhouse sheet should NOT be expected to
perform longer than recommended by the
manufacturer. Your greenhouse plants will only
suffer if you put off replacing your greenhouse
plastic past the recommended replacement
interval due to decreased transmission of
sunlight.

84. THANK YOU