|Authors: ||C. Gilli, C. Camps, Y. Fleury|
|Keywords: ||energy saving, humidity, heat pump, glasshouse climate, botrytis|
In greenhouses, humidity control is a crucial topic.
Air humidity has indeed an influence, not only on the development of fungal diseases such as botrytis, but also on the growth of plants.
High humidity reduces transpiration and therefore the transport of nutrients.
Agroscope compared a conventional dehumidification by heating-ventilation to a dehumidification by condensation with a heat pump in a soilless tomato crop.
The trials were performed in two compartments of a Venlo type greenhouse, one of which was equipped with a heat pump (MicroDéshu by ETT). They took place during the seasons 2013 and 2014. Both compartments were conducted with an energy saving management by applying temperature integration and differentiated management of the screens.
For both seasons, tomatoes 'Endeavour' were planted on February 14th in 2013 and on January 7th in 2014 in coco peat, at a density of 3.5 stems m-2. The energy consumption was measured by thermal energy meter (Multical® 601 by Kamstrup) with Pt 500 sensors.
Plant growth, yield, fruit quality, climate and energy consumption were monitored in both compartments.
In 2013, an energy saving of 15% was obtained with the heat pump.
In 2014, it reached 25%. The difference between the two years is due to earlier planting in 2014. No differences in plant growth, yield and fruit quality were measured between the two types of dehumidification.
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