Clever hose keeps greenhouses green



A greenhouse hose is a critical – and problematic – element for the agricultural industry in the Netherlands.

The Netherlands leads the world in both greenhouse cultivation and the technologies necessary to maintain optimum growing conditions and output. In 2010, the total area for vegetables under glass was 4850 hectares, producing 1540 million kilograms of exported fresh greenhouse vegetables.

There are three main types of greenhouse: “cold”, using the sun as a heat source; “frost”, in which a low-power heating system maintains a small temperature difference between outside and inside temperatures; and “warm”. This last condition is the greenhouse environment typically used by Dutch growers, deploying new technologies and methods in robotics, water and waste recycling, lighting and energy efficiency.

The main Dutch system of greenhouse heating uses an overhead suspended hot water steel pipe network interconnected with flexible hoses that can be raised or lowered to make room for equipment and machinery used inside the greenhouses and to deliver heat to the optimum position of growth for a plant. In the 1980s the hoses used in these systems were constantly giving growers problems, one of the most serious being the release of toxic gases from the hose material that could kill crops.

Trelleborg has found a solution for this.

Olivier Libes, Marketing and Product Development Manager for fluid handling solutions at Trelleborg explains: “In response to serious problems with the hoses being used in many greenhouses, we developed a dedicated hose, Kledam, which has become the de facto standard.

“We worked in collaboration with Dutch greenhouse builders and installers, with substantial input from heating technicians and agricultural engineers, to produce a hose that has exceptional resistance to wearing, aging and weathering. It’s flexible and remarkably reliable, with zero emissions of toxic gases.”

Each year the Kledam hose undergoes and passes rigorous testing.

Andre Persoon is the heating engineer at Certhon, one of Holland’s leading greenhouse design, construction and installation companies.

“We supply greenhouses and installations worldwide and have a reputation for excellence in greenhouse horticulture solutions. It’s vital for us to know that components in our systems are the best.

“There are three critical criteria for the hoses that we use to connect the steel heating loops: The hose material cannot give off any toxic gases, it needs to be flexible and strong to cope with the variations in height of the heating loops, and it must seal cleanly and tightly over the connectors. The Kledam hose system fulfils all these requirements and has never let us down.”

Equally enthusiastic is Arjen Bonneman, director of Arbon Agenturen BV, sole distributor for the Kledam hose in the Netherlands.

“The hose is made of a special EPDM (ethylene propylene diene monomer) compound developed by Trelleborg for the inner tube, reinforced with synthetic textile material,” he says.

“It’s able to withstand temperature ranges of –30°C to +95°C and performs superbly. It has rope-like flexibility, the strength of steel, does not leak, and despite wide variations in environmental conditions is very durable.”