A high efficiency ventilation system may include a partition configured to separate a supply air stream and a return air stream, an energy recovery ventilator, a heat recovery ventilator, a refrigerant flow controlling condensing unit, and a direct expansion coil. The refrigerant flow controlling condensing unit may be configured to send a refrigerant to the direct expansion coil and configured to receive a refrigerant from the direct expansion coil. The direct expansion coil may be disposed between the energy recovery ventilator and the heat recovery ventilator. The high efficiency ventilation system may be configured to supply ventilation air to a controlled environment at a particular temperature and a particular humidity.