EnergyPlus IdealLoadAirSystem vs. Internal Gains

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I run a simulation with HVAC:Template:IdealLoadAirSystem with a constant heating setpoint 20°C (in January, max outside temperature 13°C). Then i calculatet - from the Zone Ideal Loads Zone Total Heating Energy the - the required Energy in Watt. Imported that file through schedule:File and add "ElectricEquipment" with schedule Name (the name from schedule:file) + delete the IdealLoadAirSystem.

The result I expacted: The zone air temperature is 20°C The result I get: The Electric Equipment Total Heating Energy is the same than the Ideal Zone Total Heating Energy. But the temperature i different (up to 2K). Has anybody an idea?