• Greenhouse cooling

Modern growers are accustomed to taking the best possible decision under great pressure. As a horticultural entrepreneur, you know how important it is to stay cool under all circumstances. No wonder greenhouse cooling has become such a hot item in recent years. It has certainly proven its positive effect on production by now, both in the quantitative as in the qualitative sense.
 
Starting with the growth of certain types of orchids, such as the Phalaenopsis, application of greenhouse cooling has swept through the sector, with the speed of a blustering North-Easterly gale. Wilk van der Sande has completed many successful projects by now, in the cultivation of roses, freesias, calathea crocata, dendrobium, sweet peppers and tomatoes.

The number of options for its use is therefore growing quickly. It’s possible to cool above the crop for example, or under it, while the use of air hoses or the JSK allows you to distribute the cooled air evenly throughout the greenhouse.

Each working situation requires its own solution
The correct application of greenhouse cooling requires a sound approach. Together with you, we therefore start by identifying your wishes and your specific company situation. Each individual crop requires a different type of cooling, for example. In a vegetative crop such as tomatoes for example, where a great deal of moisture evaporates, it is important to dehumidify, while a crop of phalaenopsis, for example, certainly does not require dehumidification.
 
In this inventory phase, we answer a large number of essential questions together with you, such as:
  • How many days of the year do you require cooling and how are they distributed throughout the year? 
  • What are the characteristics of your crop? Some crops are very sensitive to cooling under the growing tables for example, due to the roots becoming too cool, resulting in bud loss. In such cases, it is more advisable to cool on top.
  • Is there a combination with the use of a CHP? In that case, water cooled cooling is always the best option. 
  • What maximum outdoor temperature is the basis on which you determine the required maximum cooling capacity?
  • Where can the cooling unit best be located at your company? How close is your company to a built-up area and how great is the risk of noise complaints?
  • Is there any form of surface water in the direct vicinity of your company for the purpose of water cooled cooling? If not, what are the options of installing a cooling tower?
 
These are just a few random examples of questions to be answered together with you in the inventory phase. Only when all influencing aspects have been mapped out, can the best alternatives be assessed in terms of their usefulness in your working situation. It will come as no surprise that many calculations are also made in this phase.
 
It is precisely when investing in cooling that attention must be paid to the investment costs and the operating costs of the applications. This is the basis upon which to decide which application offers the best long-term profitability. This is an extremely important aspect when choosing between water cooled and air cooled cooling units.

Heating using the air conditioning units
A cooling unit forms the basis for cooling the soil or the greenhouse. An added advantage is that the air conditioning units can be used not only for cooling but also for heating purposes. After all, the batteries in the air conditioning units can be fed with both cold and warm water. If you choose to fit the air conditioning unit with both cooling and heating batteries, you can also control other elements of the greenhouse air, the humidity for example.

Minimisation of required cooling capacity
The realisation of greenhouse cooling is a complex matter, which requires great expertise. The required cooling capacity must be determined very accurately, for example.The optimum capacity plays an important role with a view to profitable operation.

For example: on a beautiful summer’s day, the radiation is approx. 800 to 900 watt/m².
After deduction of the radiation stopped by the glass and the greenhouse profiles, the effective residual radiation is approx. 650 watt/m². The light radiation is roughly equal to the heat production, therefore a cooling capacity of at least 650 watt/m² is required. The required capacity can be limited through the use of roofing chalk or a screen installation. The experts at Wilk van der Sande blow neither hot or cold when it comes to such calculations. They have such vast experience in this field that they can help you determine the most economical solution for your working situation.

Our specialists regularly install a wide variety of solutions in the field of greenhouse cooling. The most common (sub-)applications are:
  • Wilk van der Sande | PO Box 90 | 2685 ZH Poeldijk | Netherlands | T +31 174 24 57 27 | F +31 174 24 87 39