"Diffused glass is not good and far too expensive"

As an alternative to installing diffused glass, growers can apply diffuse coatings on greenhouse roofs. These coatings are a result of the research departments of the manufacturers. According to Jeffrey Pouw of coating manufacturer Hermadix, "coatings give better results and are cheaper than diffused glass." This is Pouw's reaction to the immense amounts of scientific reports that claim that diffuse glass is a better solution.

Despite the fact that the success of installing diffuse glass needs to be determined individually for each project, Pouw is irritated immensely by the scientific reports where headers proclaim something like ‘there’s nothing better than diffused glass’. "This research provides nothing substantial and is untrue," Pouw says.

According to him, the research is not carried out independently. "Research agencies conduct research for a lot of money. Results are formulated in a way to make the client happy. In most cases, the reports then invariably conclude that more research is needed," Jeffrey said.

Jeffrey advises growers who have doubts about diffused glass or diffuse coating to delve deep into the subject themselves and inquire for information about transmission values, haze percentages, diffusing method etc. "After all, that’s what it’s all about."

Hermadix manufactures diffuse and other greenhouse coatings and has its own fabricating plant in Aalsmeerderbrug, the Netherlands. Hermadix' products are exported to 94 countries.