The invention discloses a
fresh air system and a control method thereof. The
fresh air system comprises a
refrigerant conveying device, an indoor unit and a controller. The
refrigerant conveying device comprises a compressor and a four-way valve. The indoor unit comprises a
fresh air inlet, a fresh air outlet, an exhaust air inlet, an exhaust air outlet, a first
heat exchanger, an exhaust fan, a throttling device, a second
heat exchanger and a forced draught fan, wherein one end of the throttling device is connected with one end of the first
heat exchanger, and the other end of the throttlingdevice is connected with one end of the second heat exchanger. The controller controls the exhaust fan, the forced draught fan, the compressor and the four-way valve according to a selected operationmode and set target parameters, outdoor fresh air entering the
system from the fresh air inlet flows through the second heat exchanger and the forced draught fan to be fed into a room through the fresh air outlet, and
indoor air entering the system from the exhaust air inlet flows through the first heat exchanger and the exhaust fan to be exhausted out of the room through the exhaust air outlet. The fresh air efficiency can be improved,
energy consumption is reduced, and the using seasons of the system are extended.