The traditional groundwater source heat pump air conditioning system directly uses groundwater to heat the evaporator of the heat pump unit

and the low-grade thermal energy stored in the groundwater is not effectively utilized. Given those problems

a novel groundwater source heat pump air-conditioning system preheating fresh air with groundwater was proposed. The primary feature of the presented system is the cascade utilization of low-grade energy

namely the novel system preheats fresh air by groundwater at first

then the groundwater is recycled by the heat pump unit for the secondary utilization

which is beneficial to improve the utilization rate of low-grade thermal energy of groundwater and remarkably save energy consumption of heat pump unit. The operational principle of the novel system and air treatment method in the heating mode was analyzed and the hourly heat loads of an academic communication center in the whole heating season (120 days) in four selected typical cities (Wuhan

Changde

Beijing

Zhengzhou) was simulated with DeST

moreover

a comparative study on heating characteristic and energy consumption between the novel system and conventional groundwater source heat pump air-conditioning was conducted. The results showed that the energy consumption of the novel underground water source heat pump air conditioning system is much lower than that of the conventional groundwater source heat pump air conditioning system. The innovative groundwater source heat pump air conditioning system is preferred for hot summer and cold winter area and cold region in China. Moreover

the energy saving rate is more than 50% in each region

and it should be noted that the energy saving effect is better in hot summer and cold winter area than cold region.