A good ventilation of the product is essential for storage with a high efficiency and reducing storage losses of for example potatoes and onions. Tolsma-Grisnich has developed several products, which can be used for both box and bulk storage. These ventilation systems have been developed especially for the needs of our customers and are widely applicable.

Circulation fans

Circulation fans are hung in storage facility roofs to prevent condensation build-up on ceilings. As it builds up, condensation leaks onto stacked or loosely poured products, causing them to rot. To prevent this from occurring, circulation fans produce constant airflow over the products when no ventilation is provided. Heat stabilisers Heat stabilisers are fitted with a heating coil that produces … Read more


The Tolsma-Grisnich fans are developed and produced in-house and are unique in its kind. The fans are designed to ensure a long life and a high efficiency. Read more

Air ducts

The semi circular air ducts are suitable for the ventilation of agricultural products, such as potatoes, onions, carrots and tuberous products. Read more

Quadro Air-mix units

The Quadro air-mix unit is specially designed for box storage. The internal air is mixed with fresh air from outside until the required ventilation temperature has been reached. Read more