Hi, There is one called  Humidifier:Steam:Electric: applied like thsi
Humidifier:Steam:Electric,
  Humidifier 1,       !- Name
  FanAndCoilAvailSched,   !- Availability Schedule Name
  0.1,           !- Rated Capacity {m3/s}
  autosize,         !- Rated Power {W}
  2700.,          !- Rated Fan Power {W}
  2000.,          !- Standby Power {W}
  Heater Air Outlet Node,  !- Air Inlet Node Name
  Air Loop Outlet Node;   !- Air Outlet Node Name
Cheers,
T