Sectional defrost is a control method where frost formed in the heat recovery system is defrosted in controlled sections. In practice, this is an energy-efficient way to defrost.
Sectional defrost means a defrosting method where:
- The heat recovery cell (HR cell) is divided into sections (e.g., 2–4 sectors).
- In frost protection mode, the cell is defrosted section by section using the heat from the exhaust air.
- Other sections continue heat recovery simultaneously.
Technical Benefits
When defrosting is targeted to separate sections, the air handling unit’s energy efficiency and performance remain consistently high.
With sectional defrost, it is possible to maintain:
- Stable airflow
- Energy efficiency – optimized heat recovery
- System reliability – steady operation even in freezing conditions
- Indoor air balance – continuous and controlled ventilation for users.
Airfi air handling units Model 250, Model 350, and Airfi C5 all include the sectional defrost feature as standard. We recommend ensuring that when purchasing an air handling unit in this size category, it is equipped with sectional defrost as standard to guarantee energy efficiency.
