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Fan Performance

  1. Aug 13, 2009 #1

    I have a fan heater which is rated at 2kW but when we check what it is actually using (voltage x current) it is only using 0.7kW.

    I am curious as to why this is?

    This is the fan:

    Are these fans 100% efficient?

    Jared James
  2. jcsd
  3. Aug 13, 2009 #2


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    Science Advisor
    Gold Member

    At what setting are you seeing 0.7kW? The specs says it will draw 2kW when set on high and the thermostat set above the ambient temperature.
  4. Aug 13, 2009 #3


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    Staff: Mentor

    If the voltage it is being run at is lower than the nominal voltage, that could explain it. Does it have a nameplate/sticker that says what voltage and amperage are nominal?

    ...they may have also rounded off their energy data. .7 rounds to 1. That's a pretty good possibility because you aren't allowed to make 2 kW heaters that run on regular residential wall power (in the US, anyway). A 2 kW heater would draw 16.7 A and residential circuits are 15 A.
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