Job offersmore »

Tweeting Growers

Last commentsmore »

Top 5 - yesterday

Top 5 - last week

Top 5 - last month

Exchange ratesmore »

Impact of screen gaps above the central path

The application of New Cultivation Techniques (in Dutch “Het Nieuwe Telen”) in Dutch greenhouses during the last years has resulted in energy savings. Instead of screen gaps, growers close their screen(s) completely and use a Ventilation Jet system to lower the greenhouse air relative humidity (and temperature) in a controllable way.

A Ventilation Jet system blows dry and cold air from the top compartment into the greenhouse to lower the greenhouse relative humidity (and temperature). By using a screen gap above the main path, the excess heat and humidity could escape. The efficacy of this system was investigated at a commercial greenhouse; the air flow through the VJ and through the screen gap as well as the horizontal temperature profile were measured in spring 2017.

The outcome was that less than 3% of the incoming air leaves the greenhouse through the screen gap above the central path; the vast majority of the air (> 97%) passes through the screens to the top compartment. It can be therefore concluded that the small gaps above the central path should not be applied in the specific greenhouse. Horizontal temperature difference (2.0 °C - 2.7 °C per 100 m) was recorded when both screens and supplementary lights were used. Closing the gap above the main path and replacing it with more and evenly spaced gaps with controllable size can probably homogenize the temperature distribution. This horizontal temperature difference did not occur when the supplementary lights were switched off.

The described study was part of “Kas als Energiebron” program, it took place at Gardener’s Pride greenhouse in Beetgum, NL and it was funded and performed in cooperation with LTO Glaskracht Nederland and the Dutch Ministry of Economic Affairs.

Source: Wageningen University & Research

Publication date: 11/14/2017



Other news in this sector:

11/21/2017 Valoya launches new line of LED grow lights
11/20/2017 Chrysal unveils new Flower & Plant Care app
11/16/2017 Parasitic plants rely on unusual method to spread their seeds
11/16/2017 Flower attracts insects by pretending to be a mushroom
11/10/2017 "Biomass heating systems can provide operational boost"
11/9/2017 US (MI): MSU modernizes greenhouse supplemental lighting
11/9/2017 First growers on Floriday
11/9/2017 "LED research scalable and practical"
11/8/2017 "Every percent more light in winter is pure profit"
11/6/2017 Re-use your drain water with an ultra filtration unit
11/6/2017 One indoor plant can combat sickness, study finds
10/30/2017 How do I decide on a water treatment system?
10/30/2017 Spectral effects of supplemental greenhouse radiation
10/27/2017 Have the sun manage your greenhouse lighting
10/26/2017 UK: Glasshouse Heating System Maintenance – are you struggling?
10/25/2017 Will this pink LED become your green thumb?
10/24/2017 Flowers use 'blue halo' to attract bees
10/20/2017 Plant escape from waterlogging
10/17/2017 How cultivation technique influences plants
10/13/2017 Adding heat to a greenhouse


Leave a comment: (max. 500 characters)

  1. All comments which are not related to the article contents will be removed.
  2. All comments with non-related commercial content, will be removed.
  3. All comments with offensive language, will be removed.

  Display email address

  new code