Sustainable construction: Energy-efficient ventilation systems

Concept
A ‘balanced ventilation system’ is a mechanical system which ensures good air circulation in the home. Stale air is drawn out of the room and replaced by fresh air from outside. Most systems are now ‘high-efficiency’. It is also possible to equip the system with a heat exchanger, whereby the heat from the expelled air is used to warm up the air drawn from outside before it is introduced into the living area.

A ‘balanced’ ventilation system is a mechanical system that both expels used air and draws in fresh air to replace it, thus achieving a balance. A traditional mechanical ventilation system only expels air.

A distribution system can be incorporated to direct fresh air into the various rooms of the house. This distribution system connects those rooms to the central ventilation unit, in which fresh air drawn in from outside is brought up to a comfortable temperature using the heat taken from the expelled air by means of a heat exchanger.

Within the house, stale air is usually drawn out via the ‘wet areas’ (kitchen, toilet, and bathroom), while clean air is introduced into the main living areas (see Appendix 5, Figure 7). To ensure that the balanced ventilation system works effectively, it is important that the building is reasonably airtight and that there is adequate air circulation in all rooms. This demands a good design with appropriate dimensioning, and proper installation of the system which must receive regular maintenance thereafter. The balanced ventilation system is chiefly used in new-build developments.

Unique Selling Points
• Balanced ventilation provides a healthy and comfortable interior climate, since the incoming air is also filtered.
• The system offers a good combination of comfort and reduced energy costs.

Climate impact
Balanced ventilation can do much to improve the energy performance of a building. The actual reduction in energy consumption will depend on a number of factors, including the type of system and its efficiency rating. A high-efficiency system with heat exchanger can easily reduce annual gas consumption by some 250 m3.

Market parties and research institutes
Brink Climate Systems, Itho*, KEMA, Priva, and Stork Air* (NB This list is not exhaustive)

Best-practices in the Netherlands
• TNT offices
• New residential development in Culemborg

Possible obstacles to international business
• Some countries place restrictions on the type of technology than can be used. For example, some restrict the use of valves in ventilation systems.
• Project developers, architects, and installation companies may not be fully aware of the requirements for a balanced ventilation system, which must be installed and maintained in the correct manner.