Greenhouse types & its components

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

1. Welcome

2. GREENHOUSE types

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 The soil should have a ph of 5.5 to 6.5 and EC of 0.5 to 0.7 ms/cm. Availability of continuous source of quality water. The ph of irrigation water should be between 5.5 to 7.0 and an EC should be less than 1ms/cm. 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 u t il i ties and inclu d ing water e le c tri c ity s uppl y . One advantage of a lean to greenhouse is that it is in close proximity to your house and allows for better monitoring plant s . A o f a lean to of your disad v an t a g e greenhouse entrance i s that s un l ight i s li m it e d.

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

15. Types of Greenhouses Glasshouse

16. 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

17. 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).

18. 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).

19. Polytu n nel

20. 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

21. STRUCTURAL COMPONENTS TRUSS

22. STRUCTURAL COMPONENTS Bottom Chord

23. STRUCTURAL COMPONENTS Struts and Chords

24. Ridge

25. Ridge Vent

26. Purlin

27. side post rafter sill curtain wall eave

28. 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