NATURALLY VENTILATED GREEN HOUSE / POLY HOUSE

 

Natural ventilated Green House (Poly House)

 

Green house having vent at top and at side is called “Natural Ventilated Green House”.  Through top roof vent and side vent the airflow continuous reduce the inside temperature. The top roof vent is designed with anti rain overlap for protection croup from inflow rain, and fixed by fully insect proof insect net also.  The Naturally ventilated greenhouse can  be mechanically or naturally ventilated for thoroughly ventilation for control of temperature. Mechanical ventilation requires exhaust fan and electricity to operate. Well designed mechanical ventilation is able to provide adequate cooling for a wide variety of weather conditions throughout many locations in the India. 

 

Type “A” with 10% top ventilation.
  • 8mtr. X 4mtr. Structure Gird:

Multispan  structure having 8 mtr. truss span 4mtr. distance between two trusses.

  • 10% Top Ventilation ( 800 mm ) clear opening placed at top ensure better ventilation and 600mm overlap to avoid direct entry of sunlight into Greenhouse.

 

 

Type “B” with 17% top ventilation.

  • Structure Grid 6 Mtr. X 4 Mtr.

Multi span structure having 6 meter span and 4 meter distance between two trusses. 

  •  17% Top Ventilation means better control over temperature.  Suitable for those crops needs more ventilation and those areas where temperature in summer is too high like Central Gujarat, Rajasthan etc. 

 

 

Natural ventilated greenhouse Structural Technical Features

  • Foundation :

Foundations are aligned by theodolite and dumpy level.  Levels of concrete are maintained as per slope required resulting proper resting of main column on the concrete. Anchoring Foundation column, Formation level of Greenhouse are perfectly maintained in concrete ensure resting of main column on concrete.

 

  • Shape :

Aerodynamic shape along on periphery is given to drift away wind flow and minimize the wind impact on the sides of Greenhouse to ensure maximum strength of structure against wind. Column runs up to top of the Greenhouse to ensure maximum strength to the structure. By Ideal selection of radius for top arches, we selected optimum radius for top chords which in to less wind pressure through vents and avoid lifting of top polythene and also reduces wind pressure due to aerodynamic design.

 

  • Joint:  

G.I. Pipes structure with Hinge Joint with G.I. Pipe members are joined to each other’s by means of clamps, angale brackets & nut bolts which ensure more strength against the vibration caused  by wind.  And all the fixtures are made from hot deep galvanized like Clamps, Nut Bolts are used for installation.

 

 

  • Gutter :

Trapezoidal shaped gutter in single piece made from G.P. sheet coil and are placed on the structure by means of modern technology. The Gutter height is  4.6 mtr. from foundation formation level to bottom of Gutter.

 

  • Side Curtains:

Curtain opens along periphery allows to minimize or maximize side ventilation as per the requirement and ensures outside cold air to flow inside and push inside hot air to outside from top ventilation. Also by closing side ventilation one can block Co2 exhausted by plant inside the the Greenhouse during night & use the same in morning to increase photosynthesis of the plant. To avoid the outside flapping of polythene curtain ensure more life of the side polythene curtain by flap controls.

 

  • Flap control & Curtain Runners:

Flap   control pipe that avoids the flapping of curtain paper & reduces maintenance due to wind pressure. Extra purlin is provided along periphery with aluminum gripper which increases strength of structure and also increases life of side polythene.

 

  • Bottom chords:

Straightness of the bottom chord is maintained for any length of the Greenhouse by means of perfect mathematical calculation, resulting more strength & good aesthetical appearance to the structure.

 

  • Aluminum Gripper :

Curvature at the bottom surface for perfect fitting on the pipes and radius is given to the edges where polythene under stress.

 

  • Corridors:

Bended / Hockey stick type corridors are used along width of the Greenhouse. Straight corridors are used along length of Greenhouse to stop displacement of main column from heavy wind resulting more strength to structure.