Wageningen University Researchers Present – Dehumidification with Latent Heat Recovery Reduces Overall Energy Consumption

During the Energiek Event, this July in Bleiswijk, NL, researchers, Jouke Campen and Marcel Raaphorst of Wageningen University & Research, provided an explanation of active dehumidification and its ability to reduce greenhouse energy demands,

“The researchers illustrated their story with cases from research and practice in various crops (lit tomatoes, tulips, chrysanthemums). The calculation examples show that active dehumidification, such as DryGair, has a clearly positive effect on the energy balance and that latent heat recovery reinforces this positive impact.”

The following excerpts are taken from a Kas Als Energiebron article, originally published in Dutch.

How Humidity Control Increases Greenhouse Energy Demand

“Compared to an empty greenhouse, a conventional greenhouse with a lot of crops requires four times as much heating, in order to maintain the right temperature. This is entirely due to the plants’ evaporation and the need to remove excess moisture through air vents and screen gaps. In doing so, large amounts of heat and CO2 are also lost, which must be replenished.”

Reducing Heating Demands and Saving Energy Through Active Dehumidification

“Numerous systems have been developed to enable more energetically (and financially) efficient moisture control, such as forced ventilation with relatively dry air from outside. However, systems that actively reduce moisture and simultaneously recover the latent heat present in the moisture, for immediate or later use as sensible heat, are even more energetically efficient.”

“In a well-attended workshop on active dehumidification with latent heat recovery, Campen and Raaphorst discussed this in more detail. The focus was mainly on systems based on mechanical air treatment. These contain cooling blocks to condense the moisture (releasing the latent heat) and heating blocks to heat the cooled greenhouse air before introducing it back into the greenhouse. Systems such as DryGair bring the harvested latent heat directly back into the greenhouse.”

Active Dehumidification Provides Multiple Benefits

“Growers should definitely take into consideration that active dehumidification can contribute to a better and more homogeneous greenhouse climate. And that’s good for production, product quality, crop health and the control of diseases and pests.”