• Maintaining target heating temperatures during winter dawn hours with efficient energy use
• Suppressing vertical thermal stratification in a high-ceiling space
• Uniform airflow at 0.5 m/s across all nine tiers

Heating challenges before dawn in winter

When outdoor temperatures drop sharply before dawn, maintaining strawberry-growing temperatures in the 9 m-high space requires substantial heating capacity and precise control.

Airflow dead zones in nine-tier racks

Tall, densely stacked racks obstruct circulation, allowing upper tiers to overheat while lower tiers suffer cold damage and uneven growth.

Difficulty achieving uniform air velocity

Delivering the optimal 0.5 m/s airflow for photosynthesis and transpiration evenly through narrow rack spaces across nine tiers is extremely difficult with conventional duct design.

Hybrid supplementary HVAC

The precision control of air conditioners complemented the heat-exchange capacity of unit coolers. Coordinated operation during high-load winter dawn hours reduced energy use while maintaining the setpoint.

FlowSox uniform airflow across nine tiers

Directional perforations delivered 0.5 m/s airflow throughout the 8 m-high racks. Static pressure control maintained fresh-air delivery through to the farthest zones.

Minimizing thermal stratification

Circulation fans and fabric ducts moved warm ceiling air down to the lowest tier, minimizing temperature differences from the first to the ninth tier.

Stable target temperatures before dawn

Hybrid heating maintained temperatures suited to strawberry growth even during the coldest hours, preventing cold-damage risks.

Crop-specific low-speed airflow

Airflow averaging 0.5 m/s reached throughout the foliage, supporting efficient crop growth.

Energy-efficient, data-based operation

Efficient load sharing between air conditioners and coolers reduced energy consumption compared with operating a single system and established precise, data-based HVAC control.