Van der Hulst Rose Nurseries Utilize 24 DryGair Units to Regulate Humidity – FloralDaily Magazine
FloralDaily magazine reports on a unique tour of Van der Hulst rose nursery in Meterik this past October. The visit took over 20 participants from Germany and the Netherlands to Van der Hulst’s advanced greenhouses, which utilize DryGair for optimal climate control and energy savings.
The visit is a part of the Agropole Innovates project, by Agrobusiness Niederrheinz and Brightlands Campus Greenport Venlo.
The following excerpts are taken from the original article, published in FloralDaily magazine.
Presenting DryGair’s Benefits at Van der Hulst Nurseries
Humidity is one of the most basic factors in controlled environment agriculture. Plants absorb water through their roots, which in turn evaporates from the leaves. This is necessary for the plants’ growth, but also creates a very humid environment, which reduces further evaporation and increases the risk of fungal disease outbreaks.
“In order to regulate humidity, greenhouse growers usually open the screens and roof windows, letting the humid air out. But this leads to large energy losses. That’s what led to the development of DryGair.”
DryGair’s energy-saving abilities were presented by Eef Zwinkels, technical account manager at Royal Brinkman. Zwinkels grew up in a horticultural company and has worked in horticulture his entire professional life, lending him the knowhow to showcase the DryGair system in detail:
“DryGair uses much less energy than humidity control via ventilation. To extract four liters of water from the air, the device requires only 1 kW.”
According to Zwinkels, 50% of energy can be saved this way.
“The device hangs above the crop and sucks in greenhouse air through the grilles on the sides of each unit. The moisture condenses on these grilles, and the unit blows out slightly warmer air through the top vents. Additional advantages are that CO2 remains in the greenhouse longer, and the extracted water can be reused as clean irrigation water.”
Van der Hulst’s Success Using DryGair
DryGair is already being used successfully at Van der Hulst’s rose company. Roses are grown at three locations, and a total of 24 DryGair units have been installed. All three locations have achieved a high certification standard, receiving both MPS-A+ and MPS-GAP certificates.
They’ve already gained plenty of experience with DryGair, because a lot of emphasis is placed on optimal climate management. Each of the three companies grows several rose varieties with very similar cultivation requirements.
Dry air and optimal temperatures ensure that the flowers don’t grow too quickly, leading to soft tissue development. Rather, they’re grown slowly, which results in stronger stems and high-quality flowers. The goal is to grow sustainable, innovative, large-flowered roses.
EU Regulations Regarding Lighting Increase Dehumidification’s Benefits
The EU’s eco-design regulations have forced companies to switch to energy-saving lighting from 2023. For this reason, LED lights are becoming more and more popular in large-scale greenhouses. These generate less heat, leading to lower greenhouse temperatures, which in turn results in higher relative humidity levels.
Promoting Innovation in the German and Dutch Horticulture Sector
Anke Schirocki, Director of Agrobusiness Niederrhein, welcomed the exchange between the participants. These included representatives of nurseries, universities, research institutions, and entrepreneurs, from the supply industry and agribusiness services. “The exchange between different links of the agribusiness value chain is exactly what we wanted to promote with this project,” said Schirocki.
