The electric heater I bought is design for the RV & Boat industry so it can take a splash of water. It is also thermostatically controlled.
Specs 600/900/1500W heat settings (I use 900W as mentioned above that the heater would not last that long running on max the entire time). Also with the 1500W/ high fan, the amp draw is 12.8 amps. If you a running an extension cord the performance of the heater will be affected by the resistance of the cord. So length of cord and also gauge - it would need to be 10 or 12 gauge ( the thicker, the better). Two fan settings. Overheat protection.
Brand is Caframo & the model is True North
This heater would probably heat the 6'X8' space.