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How do I determine the number of fans in a greenhouse?

To calculate the number of fans in a greenhouse, it is important to have three basic factors available. With these basic factors, Vostermans Ventilation can calculate the number of fans step by step.

Basic factors
Greenhouse dimensions: Start by calculating the volume of the entire greenhouse and make a note of the dimensions.

Circulation rate: The circulation rate is equal to how many times per hour the air is circulated in a greenhouse. In practice, we often see that a circulation rate of 2 or 3 is chosen. In some situations, a circulation rate of 12 or higher is chosen. The ideal circulation rate depends on the situation on-site, and the crop.

Fan specification: Finally, it is important to know how many m3 of air the fan moves per hour, and what the maximum recommended usable throw is. Vostermans’ Greenhouse Fans are divided into 3 lines: the 5,000, 7,000 and 8,500 m3/h versions. You can find this information on the lid of the fan motor, in the brochure, or the datasheet.

Current situation
In the current situation, our assumptions are based on a greenhouse of 160,000 m3. If we multiply this by the circulation rate of 3, we know that the circulation fans have to move 480,000 m3 of air per hour.

Step 1: Number of fans to achieve the circulation rate
To know how many m3 of air must be circulated each hour, we can simply divide this by the number of m3 that a fan moves per hour. Depending on your wishes, you can choose a fan from the 5,000, 7,000 or 8,500 m3/h line. In this case, we have assumed an ideal situation with ideal greenhouse sizes and suspension points at any desired location. We have included these variables in steps 2 and 3. We then arrive at the following number of fans:

4,850 m3/h: 99 fans
6,500 m3/h: 74 fans
8,700 m3/h: 55 fans

Step 2: Distance between fans
To prevent fans being located outside of each other’s airflow, we recommend that you do not exceed the recommended throw. We have verified this recommended maximum usable throw in practice, with smoke tests. In practical terms, this means that with hanging options every 4 meters, a fan with a recommended throw of 35 meters will be suspended at a distance of 32 meters.

Step 3: Greenhouse dimensions
Finally, the fans should be evenly distributed along the length of the greenhouse. In practice, the length of the greenhouse is often not divisible by the fan distance calculated in step 2. In this case, the fans are hung even closer together to obtain the right distribution in the greenhouse, and to avoid exceeding the maximum recommended throw.

For more information:
Vostermans Ventilation

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Israel announces creation of global seed company

Two Israeli seed producers, Nirit Seeds and TomaTech, have joined forces to create Israel’s largest vegetable seed company. This synergy will enable unique seed breeding research and development that will accelerate the company’s growth in the international seed markets.

Upon completion of the merger, the company will have more than 80 employees worldwide, including molecular biologists, breeders, agronomists, and others.
The company will improve its breeding activities in Israel, Spain, Mexico and Italy, as well as significantly expand its representation in the Netherlands and North America, with a particular focus on growing vegetables in high-tech greenhouses.

Nirit Seeds is one of the most successful internationally traded tomato and pepper seed producers, investing in the development of revolutionary genetic technologies. TomaTech is one of the leading tomato seed companies in Israel, developing premium varieties, including those resistant to the dangerous Tomato Brown Ruffle Virus (ToBRFV).

The production of crop seeds is one of the most advanced and high-tech sectors in Israel. According to the Seed Department of the Federation of Israel Chambers of Commerce, seed exports currently generate $200 million in annual revenue. There are about 25 large and medium-sized companies in the local industry.

For reference. According to market research, the global vegetable seed industry is valued at $8 billion a year and is growing at a CAGR of 8%.

Prepared according to

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Karachay-Cherkessia became one of the leaders in the production of greenhouse vegetables at the end of 2021


Greenhouse vegetable production in 2021 reached a record 1.4 million tonnes. According to the Ministry of Agriculture of the Russian Federation, the leaders among the regions in this segment are the Karachay-Cherkess Republic, Lipetsk, Moscow, Kaluga, Volgograd, Novosibirsk, Saratov, Chelyabinsk regions, Krasnodar and Stavropol Territories, the Republics of Bashkortostan and Tatarstan. These regions account for more than 60% of the total production in the country. The intensive development of greenhouse projects in our country helps to provide Russians with fresh vegetables all year round. Last year, the harvest in winter greenhouses updated the 2020 record – more than 1.4 million tons of products were received. Including the production of cucumbers amounted to at least 830 thousand tons, and tomatoes – 590 thousand tons. It is expected that by 2025 the volume of vegetable production in year-round greenhouses will be at least 1.6 million tons of vegetables.


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December: Special Year Overview

In 2022, it will be 22 year since the new millennium started. Can’t believe it? Neither can we, but it is true. Before we go there, it is time to reflect on what has happened this year. Over the next couple of weeks, we will look back at 2021 and we will highlight the most important events that impacted the industry.

New greenhouses, events, even a few shows, technical novelties, and all other relevant news will pass by, offering you something other than Covid to talk about during Christmas and New Years’.


Wish your customers Happy Holidays
This special also offers an opportunity to put your company in the spotlight with a banner in this special box. This banner can be booked until December 24 on our newsletters. For more information, feel free to send an email to: 

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