Ventilation with heat recovery is the most energy-efficient type of ventilation, as it uses the heat or cold energy of the exhaust air to heat or cool the supply air.

• Maintenance requirements must already be taken into account during the design phase to ensure that parts of the ventilation system can be easily accessed for inspection or cleaning.
• It is not desirable to install the fresh air supply ducts and the indoor air exhaust ducts located outside the building close to each other to prevent the ventilation equipment from supplying the air that has just escaped from the house back into the building.