This presentation consists of the types of greenhouse,site selection, components, construction etc.

3. WHAT IS A GREENHOUSE ?
• Framed and inflated structure
• Covered with transparent or
translucent material
• Crops could be grown under
condition of at least partially
controlled environment
• Large enough to permit persons
to work with in it to carry cultural
operations

4. SITE SELECTION
1. The soil should have a ph of 5.5 to 6.5 and EC of 0.5
to 0.7 ms/cm.
2. Availability of continuous source of quality water.
3. The ph of irrigation water should be between 5.5 to
7.0 and an EC should be less than 1ms/cm.
4. The site of construction should be elevated than
surrounding.

5. 5. The selected site should be pollution free.
6. Transportation facility for the greenhouse produce
to the nearby market
7. Sufficient land should be available for future
expansion.
8. Easy and cheap availability of labourers

6. GREENHOUSE ORIENTATION:
Major factors-
• Solar Radiation and Winds
• Single span : east-west orientation
• Multi span : north-south orientation
• Vent opening towards East side.
• Lengthwise slope – 0 to 2%
• Widthwise slope – 1.25% to 2.5%
• Maximum width of Greenhouse – 40 m

7. TYPES OF GREENHOUSE
• Even Span
• Uneven Span
• Lean-to
• Quonset
• Gothic Arch
• Curvilinear
• Dome Shaped

8. lean to
uneven-span
even-span
ridge-and-furrow

9. LEAN TO
GREENHOUSE
A lean to greenhouse is
attached to a home or building
allowing for easier access to
utilities
and
including
water
electricity
supply.
One advantage of a lean to
greenhouse is that it is in close
proximity to your house and
allows for better monitoring
plants. A
of a lean to
of your
disadvantage
greenhouse
entrance
is that sunlight
is limited.

10. EVEN SPAN
• Greenhouse with two roof
slopes of equal pitch and width
Benefits:
• Excellent light, ventilation, and
temp control
Disadvantages:
• Wasted heat air in the gables

11. GOTHIC ARCH
• Pointed Arch Roof
• Trusses have been
eliminated
• Not as popular today
• Can have sidewalls
• Side walls are a short
base wall of a solid
material

12. QUONSET
• A greenhouse with a semicircular
arch that starts at ground level or
on top of a sidewall
–(Half moon shape)
• Benefits:
– Less Expensive to construct
– Few shadows
• Disadvantage:
– Cannot handle as much wind
and snow

13. RIDGE AND FURROW
• Several greenhouses connected
along the length of the eaves
• Benefits:
– Large interior areas
– Reduced heat loss
– Less expensive construction
• Disadvantages:
– More difficult to control pest and
temperature
– Difficult snow removal

14. SAW-TOOTH CONSTRUCTION
•Naturally ventilated
greenhouse.
•No automation
•Ventilation capacity – 8 % -
10%
•Wide span.
•Grid – 8m x 4m

16. Types of Greenhouses
Glasshouse

17. Glass House:-
•As its name indicates, glass is used as glazing material in this
greenhouse.
•Perhaps this is the first and oldest among all types of greenhouse
structures.
•Glass panels are fitted with the help of a wooden or metal frame.
•It can be of any shape and size and it is pretty effective for winter
cultivation, but due to increase in day temperature in summer, it
becomes unfit for cultivation during summer.
•High initial cost, difficulty in construction, and frequent damage of
glass panels by strong winds are other discouraging factors.
•In hilly regions, only a few of such structures are found for research

18. Net House
•Net house is a framed structure made of materials such as GI pipes,
angle iron, wood or bamboo.
•It is covered with plastics net (Nets are made of 100% Polyethylene
thread with specialised UV treatment) having different shade
percentages.
•It provides partially controlled atmosphere and environment by
reducing light intensity and effective heat during day time to crops
grown under it.
•Hence round the year seasonal and off-season cultivation is possible.
•Nets are available in different shade percentages or shade factor i.e
15%, 35%, 40%, 50% 75% and 90% (for example 35% shade factor
means - the net will cut 35% of light intensity and would allow only
65% of light intensity to pass through the net).

20. Polytunnel
• A polytunnel (also known as a polyhouse, hoop greenhouse or
hoophouse, grow tunnel or high tunnel) is a tunnel typically made
from z35 Steel and covered in polythene usually semi- circular, square
or elongated in shape.
• The interior heats up because incoming solar radiation from the sun
warms plants, soil, and other things inside the building faster than
heat can escape the structure.
• Temperature, humidity and ventilation can be controlled by equipment
fixed in the polytunnel or by manual opening and closing of vents.
Bhattacharyya, Pramit (May 17, 2012).

21. Polytunnel

22. CONSTRUCTION
• To maintain micro climate desired by the crop to be
grown.
• Semi-permanent structures and are designed for a
service life of 25 years
• Structure withstand loads due to its own weight,
wind, snow, hanging basket
• Should allow maximum light transmission

23. STRUCTURAL COMPONENTS

24. STRUCTURAL COMPONENTS

25. STRUCTURAL COMPONENTS

30. Sash Bars
• Run perpendicular to the purlins.
• Attached to the purlins.
• Hold the glazing in place.
• Sometimes built with a drip groove or channel to
catch condensation that forms on the inside of the
glass panels