how to keep my house warm in winter , while still getting outside fresh but cold air circulation?
We recently retrofitted a ducted system in our 3 floor ,total 300 sqm house. its just a fan unit with iq air perfect 16 filter attached at intake end, clean air is forced into all rooms, while dirty air is pulled out from common areas only ( one exhaust point per floor only). The whole fan unit (from panasonic) and iq air unit is fitted in a small machine room, with inlet and outlet plastic pipes connecting to outdoor. The problem is that cool air from outside , even though well filtered, makes the rooms very cold in shanghai winter. can i just let inlet and outlet of air be inside the machine room, instead of opening towards outside, this way the air will be continuosly circuilated, but will be stale air, not fresh air. or i just leave a small opening in otherwise air tight machine room , so that only partial fresh air - stale air exchange happens... compared to the present system where all exhaust air is thrown out (heat lost) and fresh cold air is blown in...
The best solution to your problem is a Heat Recovery Ventilation unit. These units work as "balanced" ventilation, meaning that they bring in the same amount of fresh air as they exhaust. They save energy and improve comfort by passing the two air streams through a heat exchanger. This means that the cold/hot incoming air is warmed/cooled by the stale outgoing air stream. They also include their own high efficiency air filter. If you live in a location with humid summers, look into an Energy Recovery Ventilation unit. These also provide a desiccant to remove much of the excessive humidity from the incoming air.