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  2. Fan heater - Wikipedia

    en.wikipedia.org/wiki/Fan_heater

    Portable fan heater A Japanese kerosene fan heater that burns kerosene for fuel. It contains an electric fan and computer controls. Electric fan heater. A fan heater, also called a blow heater, is a heater that works by using a fan to pass air over a heat source (e.g. a heating element). [1]

  3. Mains electricity - Wikipedia

    en.wikipedia.org/wiki/Mains_electricity

    A 50 Hz ±5 Hz vibrating-reed mains frequency meter for 220 V The world's first public electricity supply was a water wheel driven system constructed in the small English town of Godalming in 1881. It was an alternating current (AC) system using a Siemens alternator supplying power for both street lights and consumers at two voltages, 250 V for ...

  4. Heat meter - Wikipedia

    en.wikipedia.org/wiki/Heat_meter

    Right in white-blue: the calculator; in the center in bronze: the ultrasonic flow meter . A heat meter, thermal energy meter or energy meter is a device which measures thermal energy provided by a source or delivered to a sink, by measuring the flow rate of the heat transfer fluid and the change in its temperature between the outflow and return ...

  5. Watt - Wikipedia

    en.wikipedia.org/wiki/Watt

    The watt (symbol: W) is the unit of power or radiant flux in the International System of Units (SI), equal to 1 joule per second or 1 kg⋅m 2 ⋅s −3. [1] [2] [3] It is used to quantify the rate of energy transfer.

  6. Power factor - Wikipedia

    en.wikipedia.org/wiki/Power_factor

    In electrical engineering, the power factor of an AC power system is defined as the ratio of the real power absorbed by the load to the apparent power flowing in the circuit. . Real power is the average of the instantaneous product of voltage and current and represents the capacity of the electricity for performing

  7. Electricity meter - Wikipedia

    en.wikipedia.org/wiki/Electricity_meter

    An electricity meter, electric meter, electrical meter, energy meter, or kilowatt-hour meter is a device that measures the amount of electric energy consumed by a residence, a business, or an electrically powered device over a time interval. Electric utilities use electric meters installed at customers' premises for billing and monitoring purposes.

  8. Power rating - Wikipedia

    en.wikipedia.org/wiki/Power_rating

    The usual reason for the limit is heat, and the maximum heat dissipation is calculated as above. Power ratings are usually given in watts for real power and volt-amperes for apparent power , although for devices intended for use in large power systems, both may be given in a per-unit system .

  9. Specific fan power - Wikipedia

    en.wikipedia.org/wiki/Specific_fan_power

    In reality the fan system efficiency is often in the range 0 to 60% (i.e. <); it is lowest for small fans or inefficient operating points (e.g. throttled flow or free-flow). The efficiency is a function of the total losses in the fan system, including aerodynamic losses in the fan, friction losses in the drive (e.g. belt), losses in the ...