Hortivision is developing an innovative dehumidification system for greenhouses that also allows growers to cool the climate in summer. While dehumidifying or cooling, this system can simultaneously extract heat from the greenhouse, storing it in a buffer for later use. This new concept is now being tested at Holstein Flowers, a gerbera grower in De Lier, where the system will be installed in an existing greenhouse.
Hortivision was founded last year by Maurice Hartman and Hans van Tilborgh, who realized many dehumidification systems at other growers in their earlier careers. "With the concept we will now apply at Holstein Flowers, we are taking it one step further," Hans van Tilborgh says. "In large parts of the year, this installation does what such a system already does at several growers of ornamental plants and vegetables. Namely, it dehumidifies the greenhouse with outside air so that the screens can stay closed longer. If it is cold outside, the air treatment unit can also heat the outside air. Completely new to this is a solution we have added for extracting heat with the same air-handling unit. In this way, the grower can extract heat from their greenhouse and store it in a buffer."
Application at Holstein Flowers
Hortivision designed the installation on behalf of Holstein Flowers, where Van Tilborgh was already a familiar face. In 2012, he was involved in the development of the Futura greenhouse, the newest of Holstein Flowers' two locations. It was partly for this reason that the grower put the question of how to energetically improve the older Bastille location from 2003 to Hortivision. "When improving this somewhat older greenhouse, we took the Futura greenhouse as a reference," adds Van Tilborgh. "The big difference is that back then, it was an innovative climate system in a new-build situation. Now, we are dealing with fitting into an existing greenhouse and with existing installations. So it was important to first map out the current situation properly and make calculations so that we could fit the new techniques in properly."
The whole project started by taking stock of the existing installations and mapping the energy flows. Based on this, Hortivision, together with the customer, went through several possible designs. "For example, one of the ideas was also to implement a third screen installation. There were already two hanging in this greenhouse, but structurally and in terms of integration, this gave too many problems, making a third screen too expensive. Eventually, also based on the experience with air handling units in Holstein Flowers' Futura greenhouse, we arrived at a solution with multiple air handling units." Van Tilborgh and Hartman are enthusiastic about the active input by the grower. "Mathieu van Holstein is someone who knows what he wants and, with foresight, was looking for an installation that - maybe not now - but in the future can also extract energy from the greenhouse. This is how the idea and eventually the design for air handling units that can recover heat and then store it in a buffer came to us."
Energy-efficient and future-proof
After consulting firm AAB economically calculated Hortivision's design, Hortivision was commissioned to realize the system. The company designed and developed the entire system itself, and with reliable partners, the air handling units will be built into the greenhouse and connected to the central heating system. "Eventually, the 6-hectare greenhouse will have 12 double air handling units that draw in outside air from the deck and distribute it into the greenhouse via trunks. Once the air handling units are installed in the greenhouse, they can dehumidify and cool the greenhouse with outside air and possibly heat that air as well. The component in this system that provides heat recovery will be commissioned at a later stage. To use heat recovery, the grower will first have to invest in a heat pump and possibly a storage buffer. The most important thing for now is that this plant is fully prepared for this function. That is exactly where this customer's wish lay: an energy-efficient and future-proof climate installation."
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