Svensson has started production of greenhouse baffles (vertical screens) at our North American facility to help greenhouse growers reduce temperature gradients and improve the overall greenhouse climate.
Air movement and ventilation are always a positive in the greenhouse. However, gapping your horizontal greenhouse curtain to aid in ventilation can contribute to unintended effects, especially if the greenhouse attic space above your curtain is cooler than the crop space below --which can often be the case during much of the year in a northern climate). Warm air is less dense than cold air. When climate screens are gapped for ventilation, warm air moves under the screens and rises into the attic at the greenhouse’s highest point (typically in the center). This air cools once it rises above the curtain, and then sinks and moves towards the edges of the greenhouse, dropping from the attic to the crop below in a cold fall. This circular airflow contributes to a temperature gradient which spreads horizontally across the greenhouse that can equivalate to several degrees depending on the size of the greenhouse – the larger the greenhouse the more prevalent the gradient will be. This can create crop uniformity challenges, which growers typically want to avoid.
Triangular vertical screens (aka baffles or Apex screens) are installed between the gutters to help alleviate this extreme temperature variation. The baffles form seals above the curtain that divide the greenhouse attic space in smaller sections. The cold fall still occurs, but the air circulation across the entire greenhouse is now occurring across several smaller sections. The air moves less distance above the screen and does not cool as much before falling. This minimizes the temperature gradient across the greenhouse and contributes to a more even climate for your crop.
Svensson manufactures greenhouse baffles from Solarwoven Ultra, a durable, transparent material up to the challenge of greenhouse climate management. It blocks 90% of the sun’s UV radiation and saves energy when used inside the greenhouse. Withstanding hail, downpour and wind, the cover is strong and tear resistant – with a longer life than most other greenhouse plastics.
In the greenhouse to the left without baffles, a large temperature gradiant exists (blue to red arrows) and there is uneven crop growth. To the right, the greenhouse has baffles which create smaller gradiants and more even crop growth.