In the classical sense, a tunnel is the same as a greenhouse, with the only difference that during winter its covering is completely removed. Therefore, structurally, it is a simpler construction and, consequently, less expensive in terms of the frame. Accordingly, other utilities—irrigation, lighting, soil, etc.—are temporary. This is essentially a "greenhouse-semi-finished product," consisting of a metal frame in the shape of a tunnel with a polyvinyl chloride covering. These are 8m models, cheaper and simpler to equip than greenhouses.
Shelves and central aisles are typically the same as in greenhouses. The disadvantage is a less robust and less durable covering, easily damaged by sudden gusts of wind or heavy snowfall. The insulation properties of this structure are lower than those of rigid greenhouses, so it is better not to install heaters.
Additionally, the facade parts of the structure are also simpler, primarily using wood and plastic film, with no polycarbonate (the price of one polycarbonate facade, including material and labor for an 8m width, is 4500 грн).
Therefore, for seasonal cultivation, this type of protected ground structure is quite in demand and popular.
