First, start from the ventilator simple start, fan only inside a motor is used to supply air or exhaust air,then there is a two-way flow of fan, while sending wind side exhaust fan, but this is not energy saving,there will be a fresh air ventilator now, sent one side of fresh air, exhaust air the most crucial is, there is a device of heat recovery ventilation, not only energy conservation and environmental protection, is a product of the emerge as the times require.
Fresh air ventilator is divided into full heat and sensible heat.