A Heat recovery system can be installed to work with your air conditioning system or as a seperate system. The system draws fresh air from outside and stale air from inside. The air is pushed through a cross-flow structure, transferring the heat in winter and cool in summer to the new introduced air. The stale is exhausted outside and the newly heated or cooled air to transfer to the air conditioning unit for further heating or cooling if needed (If it is a separate system the air is vented back into the area). Without the heat recovery system you are either recycling stale air and having an undesirable temperature air induced into the area through a fresh air system, or heating or cooling air from the outside temperature.
Ask your HVAC engineer to add Heat recovery system to your project.