Mechanical ventilation units with heat recovery supply healthy, low-pollutant air, transmit the preheated supply air to the interior space without draughts and reduce ventilation heat loss significantly by recovering approximately 90 % of the extracted heat. User surveys have confirmed that residents in numerous developments approve of the high level of comfort and are generally happy with the ventilation systems.1 The intention of this article is to provide initial support in the design, selection and dimensioning of mechanical ventilation systems.
