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Energy-efficient cooling

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Energy-efficient cooling

In the end, the most energy-efficient installation is also the cheapest

The company Groentehof BV, supplier of ready-to-eat vegetables, expanded its production location in Helmond with two shipping areas in 2006. These are well insulated. Plus, an additional cooling system was installed, according to the latest state of the art. Thanks to the high energy prices, the energy savings and the Energy Investment Allowance (EIA), the extra investments required for this are more than justified.

Everything at Groentehof revolves around quality, freshness, shelf life and hygiene. This is immediately apparent on a tour of the production and shipping areas. In the cutting department, there are machines that have been specially developed for the company. They were not satisfied with the cutting machines available on the market. Each vegetable is washed in its own way. For drying, large in-line centrifuges and blowers are used instead of the traditional small hand centrifuges. Internal transport between the various production areas takes place using pumping systems, through shiny stainless steel gutters, instead of over conveyor belts. “Over the past few years, we have examined and optimised the entire machining and processing process”, says Stef Janssen, Head of Technology at Groentehof. “That fits with our philosophy of delivering high quality products.”

New shipping areas

We walk to the new shipping areas, which the company had built last year. Stef Janssen: “Traditionally, we supply our products under the brand name Fresh Quality. However, the market is increasingly demanding packaging with its own labels, which must be sorted out at store level. As a result, you get more and more product flows. In addition, the product range is constantly expanding with all kinds of convenience products. Think of trays of raw salads. And our market share has been increasing for years.

Groentehof wanted an installation that was as energy efficient as possible, because that is ultimately the cheapest if you look at the total operating costs

Ben ErnensAdvisor

As a result of these developments, we were running out of space. We’ve solved that problem for the next few years with the construction of two shipping areas”. In doing so, Groentehof has done everything possible to minimise energy consumption in the refrigerated rooms. Janssen points to the walls and the roof: “Those contain 12 and 24 cm of insulation, respectively. It costs a little more than the usual insulation thicknesses of 8 to 10 and 16 to 20 cm, but the Energy Investment Allowance basically covers the additional costs. You’d be throwing away money if you didn’t make use of that”.

Cooling installation

The most innovative part of the two new rooms is the new cooling installation, designed by Ernens Consult from Rolde. Advisor Ben Ernens: “Groentehof wanted an installation that was as energy efficient as possible, because that is ultimately the cheapest if you look at the total operating costs. Based on this principle, I designed a compressor cooling system with three compressors, to be controlled by means of valve seal. In addition, one compressor is equipped with frequency control, so that the entire installation is infinitely adjustable in power. To condense the coolant in the system, I ended up with an air-cooled condenser and a separate air-cooled subcooler. This allows you to achieve a temperature difference of up to 10 degrees between condensation and outside air temperature under virtually all conditions. In this way, you make use of outside air for an important part of the condensation process, which saves a lot of energy. For the cooling of the rooms, twelve dual discharge and four single discharge coolers have been installed. The whole compressor installation is on the roof, because there was no more space in the machine room. That does mean that we had to choose only low-noise parts”.


After the design was approved by Groentehof, Ben Ernens also drew up the specifications. This was sent to three companies for a tender. Voets & Donkers Koeltechniek from Schijndel came out on top. Director Marc Voets: “The tender document contained clear standards with which the machines and components had to comply. You could hardly compete on that point. We mainly won the tender, I heard later, because we had come up with a clever arrangement. Groentehof already had a Scada system for monitoring the existing cooling. However, the control of the cooling was done with all kinds of separate systems. With software that we developed ourselves, we created a link between the PLC for the new cooling system and the Scada system. Via the PLC, Groentehof can now control and monitor both the new and the existing cooling systems”. Stef Janssen: “With a few mouse clicks, I get all the information I need on my screen. Not only is this ideal for management, but also, for example, to detect faults or other errors. Now, if a complaint comes in, you can grab the monitoring data and see whether the cooling has always functioned properly during the production process and in certain rooms. That’s quality assurance”.

Calculations and copying

Just as for the extra insulation of the roof and walls, Groentehof also received an Energy Investment Allowance for the new cooling installation. Ben Ernens applied for it. Stef Janssen: “He designed the system, so it’s a piece of cake for him to fill in all the data properly”. Ben Ernens: “That’s right. Besides, I always ask for all-in quotations, in which the installer must indicate the components eligible for Energy Investment Allowance and what that yields. The most important reason is that you then get properly comparable quotations. A secondary benefit is that you only have to check the installer’s data and can simply copy it”. Marc Voets: “I’m very happy with that approach. This way, you can often take a step further in the field of energy efficiency without ultimately making the installation more expensive for the customer”.

Voets & Donkers - Groentehof



Voets & Donkers - Duurzaamheid

Sustainability is very important in our society today. We ‘have to’ get rid of the gas, and we also try to limit our use of electricity as much as possible. At Voets & Donkers, our installations contribute to sustainability in three ways: we use natural refrigerants, we develop energy-efficient installations and we make heat recovery possible.

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Voets & Donkers