|Title||Verticaal temperatuurprofiel roos : Energie besparen en lichtuitstoot verminderen bij de teelt van rozen|
|Author(s)||Weel, P.A. van|
|Source||Bleiswijk : Wageningen University & Research, BU Glastuinbouw (Rapport GTB 1445) - 42|
|Department(s)||WUR GTB Tuinbouw Technologie|
|Publication type||Research report|
|Abstract||The vertical temperature profile in a rose flower production operation is a problem when artificial light is used.
Without additional measures the lamps increase the temperature in the upper layer of the canopy. That is why
usually a heating pipe temperature between 40-50 0C under the canopy is maintained, even in summer. Also,
horizontal temperature differences are caused by internal air circulation that have a relation with the vertical
temperature differences. That circulation is the result of warm air rising and cold air dropping through pores or
small openings in a screen. An increase in light intensity or in the size of a greenhouse compartment will make
the temperature differences bigger. The best solution to these problems is to keep an airtight screen fully closed,
mix the air in the greenhouse vertically with a fan and to introduce cold and dry air from above the screen with
a second fan. The vertical fan will push the heat produced by the lamps down. This solution reduces vertical and
horizontal temperature differences and makes it possible to lower the pipe temperature. The result is an effective
reduction of light emission without negative climate effects and a 30% reduction of heat to be ventilated.