The Dutch company Doek en Draad has recently been active in the United States and Canada under the name Screen4Seasons. The company is pioneering the use of cavity screens, two screens in one installation. But what are the benefits of doing this? Gerdo Wennekers, operational manager at Doek en Draad, explains.
What is it?
"A cavity screen installation consists of two screens in a screen installation. There is a little bit of space between the screen cloths so that you get a cavity in which still air forms, which in turn provides insulation."
A double screen saves energy and has been a well-known concept for some time in the markets where greenhouse horticulture is commonplace, but for many growers investing in a double screen is still a step too far. This can be due to the higher investment costs but also additional installation problems when placed in an existing greenhouse construct in which the installment of a second screen has not been taken into account.
Nevertheless, a Dutch cucumber grower already dared to take that step some time ago. His case was highlighted during the celebration of ten years of 'Het Nieuwe Telen.' You can view the presentation of that study day here: www.kasalsenergiebron.nl.
"We have also recently sold a cavity screen installation to a company in Bleiswijk and have since started working on it," says Gerdo.
Saving on energy
One of the reasons to install a cavity screen installation that is especially applicable now, considering the current energy crisis, is the fact that, as already mentioned, it can save you a lot in terms of heating.
"With a double screen, you can save extra energy without disadvantages such as air movement between the screens, which would mean you'd have to take extra measures for temperature differences. This is not the case with cavity screens, so you don't need to take any extra measures," says the operations manager.
"In Bleiswijk, the greenhouse has a surface area of 7.2 hectares, and with the cavity screen, they can save a fair amount of heat there and at least 15 % on energy," says Gerdo.
Another reason is that the installation saves on space as it puts two canvases in one installation rather than having to place two different installations. It is also cheaper to install because of that.
"In some greenhouses, you can't fit two installations. Then this is a good alternative to save energy." Gerdo also points out that existing screen installations in greenhouses can be adapted to fit a double-screen installation.
In addition to saving on the installation cost in terms of the number of installations, there is another point of importance that Doek en Draad looks at, the installation speed. "We are continuously developing. If we think there is still room for improvement, we adapt to it. The installation speed is always important for the price, the faster the installation is placed, the cheaper it becomes for the customer, so we also focus on that a lot."
Not only is Doek en Draad active in the Netherlands but also in the United States and Canada, where the interest in cavity screens has increased over the past few years. The only difference is that they work there under a different name, Screen4Seasons.
"We do our best over there and see if we can sell the cavity screens together with our Dutch partners. In any case, we are very happy with the international attention for cavity screens," says Gerdo.