The official expression for the operating principle of the SEVi Ductless Heat Recovery Ventilation System is:

Supply-/Exhaust air system; reversible, bidirectional, non-ducted with heat recovery. 

The SEVi 160 HRV unit is the smallest available HRV unit of Seventilation with an external diameter of just 160mm.

The system is fully approved (German Centre of Competence for Construction) and independendtly tested by TZWL e.V. (European Testing Center for Domestic Ventilation Systems, NPO).

The SEVi 160 unit is one of the most maintenance-friendly ductless Heat Recovery Ventilation unit, because the complete cleaning of the unit can be done at home completely tool-free.

The hexagonal honeycomb structure of the ceramic heat buffer creates a high efficient heat storage and heat exchange.

Because of the ductless operating principle, the SEVi 160 HRV system is the perfect solution for retrofit. The system is available for walls from 160mm (6.3 inch) up to 850mm (33.4 inch) thickness.