EVI enhanced vapor injection technology Enesoon EVI low- temperature heat pump unit adopts the international leading level of EVI technology. The energy efficiency of this product is 30 higher than other similar products in low- temperature environment, it is the preferred heating unit for northern regions. - 35 - 43? operating range The main engine adopts EVI technology and equipped with an electronic valve, approved to operate heating between - 35 - 25?, cooling between 15 - 43?. To widen unit operating temperature range under severe cold and intense heat environment, improve the stability of the unit operation. Built-in hydraulic module The main engine is equipped with a water pump( optional), extension tank, water flow switch, automatic pressure relief valve, and automatic exhaust valve, etc. To keep the entire circulatory system balanced and stable at all times. The silent operating mode of the outdoor unit The main engine is equipped with automatic variable speed fan motor, the control system automatically adjusts the fan motor speed according to the outdoor air temperature monitored in real-time. Automatically reduce load according to the reduction of the heating area and enter low wind speed operation in order to achieve silent operation at night. “ Quadruple” noise reduction design The structure design of the main engine and the key control noise source between components, AT fan motor, integral wind inlet guide, sheet metal sound absorption design and anti-vibration axial fan blade, etc. It formed “ Quadruple” noise reduction. Temperature monitoring system The control system monitors temperature changes in key parts of the mainframe system, including exhaust temperature, ambient temperature, fin temperature, heat exchanger temperature, gas inlet temperature, inlet temperature, and outlet water temperature are monitored and controlled, and the operation of the compressor and fan motor able to quickly adjusted to meet the changes of indoor requirement. Non- pipe range attenuation Indoor heat transfer terminal water system is liquid water, non- pipe range leads to the decrease of air conditioning capacity. The built-in the expansion tank and other hydraulic modules ensure the highest height difference between indoor and outdoor machines remain stable.