The purpose of ventilation is to provide us with healthy fresh air indoors. It removes old, stale air and takes in clean, fresh air. Of course it's main task is to ensure that the air indoors is healthy to breathe.
The traditional method of ventilating our homes is to put a hole in an external wall or use window vents allowing vast amounts of heat energy to escape. Ventilation needs to be focused on energy and providing a healthy environment in which to live.
Using ventilation systems with heat recovery will reduce energy consumption, lower running costs and reduce CO2 emissions.