air-air heat exchange in ventilation system

Ventilation is either a question of natural or mechanical air exchange. It is often feasible minimise air leakage as it increases transmission losses, however less natural air exchange result in higher demand for mechanical ventilation in order to sustain good indoor air quality. Therefore it is feasible to combine ventilation and heating/cooling in an integrated ventilation system in order to utilise the energy in the air streams.

An integrated ventilation system is a combination of fans, controls, and heat recovering elements used to exhaust stale air from inside the building, bring fresh air in from outdoors, and transfer heat energy from one air stream to the other. The system assures a continuous supply of fresh air to the building while regaining energy normally lost through natural ventilation. In the winter months, heat from stale exhaust air is captured by the heat recovery element and transferred to the cold incoming air. Conversely in the summer, the outgoing air-conditioned exhaust air cools incoming air. Heat recovery ventilators are available as central units for large residential or commercial buildings, or as window or wall inserts suitable for small homes, apartments, and individual rooms.

Moreover an integrated ventilation system specifically designed for a building can cope with the diverse demands in air quality, for example pollutants associated with human occupancy such as CO₂, biocontaminants, tobacco smoke, radon and formaldehyde. Ventilation should occur only during occupancy and the rate should increase depending on the number of people present.

Demonstration Projects:
Tenants’ influence and CO₂ reduction, Copenhagen, Denmark
Low-income housing with reduced energy costs, Houtvenne, Belgium
New identity for urban area, Austria - Radstadt
Improving efficiency of urban energy supply systems, France - Grenoble
Leamington House – Highly efficient heating system for improving thermal performance in Portsmouth, UK
Energy efficient technology to control costs of modern architecture, Finland - Kuopio
Poland, Piaseczno: Secondary school - use of heat recovery ventilation supplied by PV

Technology Producers
www.solarvent.dk
www.halton.fi
www.enviropower.ca
www.ecovent.com
www.dynair.it