English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

Between growers there is discussion if a (controllable) gap above the central path of the greenhouse is needed to extract the surplus of heat and vapour in a greenhouse equipped with artificial lights and Ventilation Jets. Based on this discussion, this research was started at a tomato greenhouse with artificial lights to analyse the impact of this gap. To determine the effectiveness of this gap, the air flow through the Ventilation Jet was measured with an air flow measurement device, the air flow through the gap at the central path was determined using air velocity sensors and horizontal temperature differences were measured with wireless temperature sensors. Based on this study we can conclude that: (1) at this grower the measured flow of the Ventilationjet at 2 closed screens (6.7 m3/m2/hour) was much lower than expected (12 m3/m2/hour); (2) the impact of the gap at the central path was small (a maximum of 2.8% of the incoming air through the Ventilation Jets left the greenhouse through this gap), the gap at this grower is this not needed since almost all air leaves the greenhouse through the screens and; (3) in case that the artificial lights were switched on and both screens were closed, large horizontal temperature differences of maximum 2.7°C occurred.

Impact van een schermkier boven het middenpad bij een Ventilationjet systeem