AntiCondens for glass allows significantly more light into the greenhouse
Tomato grower Paul van Paassen is the first in the Netherlands to use the coating AntiCondens for glass. “It clearly leads to more light inside.” he says.
Over the course of the year, for about half the time the glass is wet with condensation. That can reduce a lot of light. Researchers at Wageningen University & Research noticed during trials in 2010 that the manner of the condensation makes a big difference: if droplets form on the glass the light transmission is lower, if a water film forms transmission may even rise. On average they found that light transmission through ordinary float glass fell by 5% due to condensation. During the low light months in particular the glass is constantly fogged up. That costs production. An anti-droplet coating could ensure that virtually no light loss occurs, according to the report made by the researchers.
Currently there is such a coating. Over the past few years Mardenkro has further developed the existing coating for plastic greenhouses, AntiCondens, into a product suitable for glass.
Paul van Paassen
First experience with AntiCondens for glass
On the advice of his crop advisor he ordered AntiCondens at the end of the season and it was applied during the crop change in December 2016. AntiCondens has to be applied to clean and dry glass. Van Paassen: “That year was very humid in the greenhouse and the glass remained wet for a long time. Then you know you are losing light,” he says. There was exactly just one dry day during that period. I had to put the heating on to remove the fumes from the just applied paint so the coating dried immediately as well.”
AntiCondens lasts just one season. When the glass is cleaned at the end of the season with a cleaning agent the coating will largely disappear.
More light in the greenhouse
The grower is very pleased with the results: “The greenhouse now looks completely different. The condensation is still there but you don’t see it. As a result, it is definitely much lighter inside.”
He finds it difficult to estimate the effect it has on production and quality because one year can never be compared with another. “But I do think that I’ve gained from it,” he says. Van Paassen intends to use AntiCondens again next season.
More light = more production
Mardenkro has measured the light transmission through treated and untreated glass. The differences were significant. On three consecutive days in May 2017 the light transmission through the coated glass was 6 to 7% better than through uncoated glass. For tomatoes, an increase in light of 1% results in 0.7 to 1.0 % more yield (source: Wageningen UR).
Preventing light loss and disease in plastic greenhouses
Condensation on the greenhouse roof is the result of air dehumidification. In plastic greenhouses steps need to be taken to prevent the condensation from causing problems.
Controlling growth with light: more in winter, diffuse in summer
For a grower, every ray of sunlight entering the greenhouse in winter is a bonus. Light is also welcome in summer, provided it is properly distributed throughout the crop. This can be achieved by combining coatings. Two vegetable growers are leaders in this field in the Netherlands.
Light gain in greenhouse after applying AntiCondens leads to more production
For crops that are switched in the summer, this is the ideal time to apply AntiCondens to the inside of the greenhouse cover. It is a good preparation for the coming humid season, when condensation droplets block valuable light. Tomato grower Paul van Paassen has been using AntiCondens for three years,...