Request for Quoatation for the Supply of Naturally Ventilated Greenhouse Kits to the Women for Women Rwanda

Specification

Minimum height for green house

 Minimum allowable 3m on both side

Gutter height

Minimum 3m with provision to fix side nets/ screen

Gutter slope

2 %

Apron

Height 1.5 m on all the four side, with g.i wire fixing arrangement. bottom of polythene to be embedded in the ground

Curtains, insect net, side ventilation rollup curtains (side netting)

Openable up to a minimum height of 5 m, on two sides (opposite to each other) with crank mechanism & 4mm diameter mesh sized insect net inside curtain.  antiflapping stripes to be used to ensure smooth movement of the curtains. Maximum 4mm of diameter for insect net

Galvanizing of steel

Steel pipes used minimum 50 microns, higher would be preferred. supplier to state the life of the structure under tropical conditions.

Columns

Min 90 mm od. x 2 mm thick, galvanized steel pipe. higher specification would be preferred.

Purlins

Min 48 x 2 mm, higher specification desirable.

Gutter (optional)

20-gauge G.I sheet or Aluminium with size 500 mm width or more so as to avoid spill over the gutter under max rain conditions. Preferably single length without joint, to be bolted to purlins with zinc plated nuts & bolts.

Fastners / Nuts & bolts

Galvanized with minimum 50-micron thick Zinc coating., higher micron would be preferred.

Poly film/ plastic cover

• Long duration plastic, more than 150 micron film, of required width & length with qualities of UV stability; Anti-drip; Anti-condensation;
• Minimum light transmission 87 % ; diffused light transmission 29 % ; Suitable for growing of tomatoes, Capsicum and cucumber. The supplier should state the life of the product under sub-tropical conditions

Poly fixing

G.I wire profiles with smooth finish for single poly fixing. Aluminum box type profile for locking double poly. Wooden battens or PVC grippers not permitted. With a view to enhance the life of the poly film, “Anti hot spot” tape or “Aluminum reflection” tape should be used at the point of contact with G.I. pipes.

Doors

If present it should be free moving bearing mounted Sliding doors, one or two doors, depending up on the size & other factors to be decided at the time of placing order. Air lock double door with disinfectant shoe wash trap.

Wind speed

Structure must be capable to withstand wind speed of at least 140 to 150 kms / hour.

Gables

To be fixed with two-way Aluminum Polylocks for locking two poly sheets together along with curtain top.

Aero-dynamic shape

If the supplier advises on a location to reduce the impact of wind and consequent damage to Poly and the structure, it is considered desirable that Poly house should be Aero-dynamic along four sides, with curvature shaped pipes 48 OD & 2mm thick, galvanized, ensuring lest wastage of space inside.

Shade net / reflective screens,

silver colored “Aluminet” or its equivalent; 50 or 70 % with collapsible mechanism, and equal to the floor area of the Poly House. Supplier to submit full technical specifications about temperature differential achieved and amount / quality of light intercepted, diffused and reflected

Drip irrigation

Drip Irrigation System should contain complete technical specification / design right from Sand filters / Disc filters to mains / sub –mains, laterals ( 16 mm ) , drippers , Micro- tubes & the Pegs matching the requirement of grower.

Drippers

Self-flushing; non drain; low profile; top outlet; four-way micro tube & pegs

Filteration System

Disc & sand filters of matching capacity and self-flushing mechanism.

Misting system (optional)

Overhead Misting System appropriately matching the requirements of the project.

Misters (optional)

High pressure system operating at 100 bars; droplet size 5microns; anti-leak; four-way spacing 2×2 m or as suggested, controller, other accessories such as storage tank, filters etc.