Comfort ventilation plus+: First time development of high efficient comfort ventilation systems that enable demand-control of room-wise airflow for new buildings and refurbishment

First time development of innovative components for comfort ventilation systems used in new buildings and renovation that enable demand-control of air flow room-wise. The outcome is a considerable reduction of the primary energy balance and a sustainable solution of problems concerning the discrepance between satisfying humidity and very good indoor air quality within the heating period.

Short Description




Starting point/Motivation

The hygienic air requirement mainly depends on the value of the occupancy rate and on the occupants' activity level. Conventional comfort ventilation systems only allow changing air volume flows for the entire usage unit. Therefore, in practice, the fresh air volumes are higher in non-occupied rooms than would be required for hygiene and humidity reasons. At the same time, rooms that are occupied by 2 or more people are markedly undersupplied. This drives people to more frequently open windows. Adjusting the system to a higher ventilation level only results in a marginal ambient air quality improvement, with at the same time a disproportionate increase of the primary energy requirement.

While we are about to reach the physical limits of present day technologies when it comes to the efficiency of heat recoverers and ventilators, the considerable potential of room-wise or zone-wise requirement adjustment to reduce primary energy requirement is currently not being exploited.

This system offers its user added value mainly in form of a marked air comfort improvement in the occupied area as compared with conventional systems. At the same time it effectively resolves the persistent problem of too low ambient air humidity at low outdoor temperatures. A key benefit for the system installer is that this system does not require a manual time-consuming adjustment of the supply air passages, as this is made automatically.

Contents and Objectives

This project focused on the development of new ventilation and control components to be used as modular system and customised software for planning support ready for mass production. Using two different solutions, a decoupling of the room-wise supplied air flow of the total air flow should be realised. The key application areas of the so-called "Komfortlüftung plus+" are flats, hotels, offices and all areas or zones with fluctuating occupancy.


In a study of variants the combination and integration capabilities of the components were analyzed using a variety of floor plans and user requirements. With regard to a rapid transition to a small series manufacturing options were inspected and passed over the components according to detailed technical requirement specifications from concept to detailed design. During prototype development new solutions were sought and tested for some functions. In order to integrate the ventilation unit visually appealing in the living area, a bespoke fitted wardrobe was developed, which can take over air-guiding function. Decisive part in the practicality of the system has an innovative control of the system. For planning and conceptual design of these new systems a simulation and planning tool was developed that allows the comparison with conventional operating modes of room ventilation.


As a result of the study of requirements concerning functionality and integration by using practical floor plans a system for new buildings and renovation was concepted. The systems can be used flexible in different situations of floor plans and occupancies. Through innovative approaches and new types of components with innovative functionality, systems could be implemented which achieve significant improvements over conventional ventilation systems in several areas. The development of the combined air distribution box as a central component of the "new building system" represents a gap closure for easy integration, flexible operation and the low cost cleanability of comfort ventilation. For subsequent installation a system was designed that allows an almost tubeless air distribution and removes a large barrier in the way to the integration of comfort ventilation in existing buildings.


Due to the closed cooperation with an industrial company for modern metal processing and next steps for the market launch the necessary capacities for mass production can be provided. In the first pilot projects, individual components are subjected to a wide field test. With the gradual integration of installers, planners, architects and builders solid advice of end users and housing developers should take place.

Project Partners

Project management

leit-wolf Luftkomfort e.U.

Project or cooperation partners

Contact Address

leit-wolf Luftkomfort e.U.
Ing. Wolfgang Leitzinger
Bahnstraße 9
A-3424 Muckendorf/Donau
Tel./Fax: +43 (2242) 72807