The main form of electric energy substitution for commercial customers is to replace the traditional coal-fired boilers with the electric ones. There are two primary options for electric heating. One is to install a system including a water chilling unit(WCU)for cooling in summer and a heat storage electric boiler(HSEB)for heating in winter. The other one is to install a system including a sole ground source heat pump(GSHP)for both cooling and heating purposes. In order to figure out the boundary conditions of the feasibility of these two different systems

an optimization model with the objective of minimizing the cost difference between these two systems is further proposed to directly solve the boundary conditions

based on the cost functions and operational constraints. Case studies and perturbation analysis are applied towards the comprehensive office buildings in Tianjin. The results show that the feasibility boundary conditions of electric heating technologies include the ratio of maximum summer cooling load and maximum winter heating load and the utilization hours for specific customers in a specific area. The HSEB+WCU system is more economic for areas with large peak-to-valley price ratios or with large diurnal temperature differences

while for those with high demand charges or those with no hot water supply but whole-day heating/cooling demand

the GSHP system is more preponderant.