Energy efficient climate control for cut flower alstroemeria

Like in most countries, in the Netherlands energy consumption is an increasing cost component. In cut flowers grown at a relatively low temperature, most of the energy is used for dehumidification. In Alstroemeria dehumidification is especially important to prevent the physiological disorder expressed as necrotic leaf tips. Research has been carried out showing that improved climate control can save 37% on heating, without a reduction on yield and even a quality, compared to a contemporary reference. Showing less necrotic leaf tips, the quality was better in the greenhouse with the energy saving strategy in December and January. This result was realized with a novel dehumidification system, a double thermal screen and temperature integration. When vapour pressure deficit was below 1.9 g/m3, outside air was blown under the canopy with an air distribution system for dehumidification. If necessary, this outside air was first heated to greenhouse temperature to prevent an inhomogeneous temperature distribution. The reference greenhouse, controlled at the same humidity set point, used a combination of slightly opening the thermal screen followed by slightly opening the vents to carry off moisture. Eventually, at a vapour pressure deficit of 1.5 g/m3 the temperature of the heating pipe was risen to lower the humidity. In the greenhouse with the energy saving concept no heating pipe for dehumidification was needed. The performance of the energy saving concept proved to be efficient.