How many Watts do my appliances use, a helpful fax inside.

Discussion in 'Indoor Growing' started by MyMindIsGlowing, Aug 2, 2005.

  1. MyMindIsGlowing

    MyMindIsGlowing Registered+

    How many Watts do my appliances use?

    Naturally, electrical usage will vary from model to model, so remember that the table below are just examples.

    Energy Consumed

    5000 watts
    Electric oven (800 for a range burner)

    5000 watts
    Clothes dryer (electric)

    3800 watts
    Water heater (electric)

    3500 watts
    Central Air Conditioner (2.5 tons)

    1500 watts
    Microwave oven

    1500 watts
    Toaster (four-slot)

    900 watts
    Coffee maker

    600-1440 watts
    Window unit air conditioner

    200-700 watts

    150 watts
    Desktop Computer & 15" CRT monitor

    15-30 watts
    Desktop Computer & Monitor (in sleep mode)

    120 watts
    17" CRT monitor

    40 watts
    17" LCD monitor

    75 watts
    Regular light bulb

    55-90 watts
    19" television

    45 watts
    Laptop computer

    6-25 watts
    Ceiling fan (36"-52"), on high speed

    18 watts
    Compact fluorescent light bulb

    4 watts
    Clock radio

    3 watt-hours
    Total power stored by an alkaline AA battery. This is to put batteries into perspective. If you could power your clock radio with a AA battery, it wouldn't even last an hour.
  2. MyMindIsGlowing

    MyMindIsGlowing Registered+

    (1) Using ceiling fans instead of the air conditioner
    ~$100, if you don't already have ceiling fans $625

    (2) Use a clothesline or a laundry rack instead of a dryer
    ~$20 $150

    (3) Washing laundry in cold water instead of hot
    none $119

    (4) Washing laundry in warm water instead of hot
    none $60

    (5) Replacing regular light bulbs with compact fluorescents
    $40 $95

    (6) Replace 1990 fridge with 2004 model
    $460+ $45

    (7) Replacing a CRT computer monitor in a home office with an LCD display
    $300+ $21

    Link for above 2 posts
    Last edited: Aug 2, 2005
  3. MyMindIsGlowing

    MyMindIsGlowing Registered+

  4. nobiee420

    nobiee420 Banned

    nice calc dude thanks for posting!
  5. BCEasy

    BCEasy Registered

    are those watts per hour of use? or watts per what time measure?
  6. Beeblebrox.420

    Beeblebrox.420 Registered+

    Watts are dimesionless unit of power. A 500-watt coffee maker is 500 watts, whether it's on for five minutes or 6 months - in the simplest of terms, it's essentially a measure of how fast energy is used. The electrical meter on the side of your house measures energy usuage, in kilowatt-hours (in the US. The UK uses kilojoules, instead, which is basically the same thing). One kilowatt-hour is the amount of energy consumed by a 1-kilowatt (1000 watt) load over a period of one hour.

    Some appliances are not labeled with power draw directly enumerated in watts. These items will have the expected load voltage listed, and the current draw, in amps or milliamps. To find out the (approximate) watts draw of such appliances, multiply the volts by the amps (convert milliamps to amps by dividing by 1000), For example, if the rating plate for an appliance reads 120 VAC @ 3 Amps, the watts draw is 120 x 3 or 360 watts. Depending on the nature of the applinace, this result may or may not accurately reflect the true power draw, as I will explain shortly, but it will be a good first-order approximation

    Other items are listed with a figure expressed in VA, or volt-amps. Typically, appliances with large motors or other heavily inductive loads, such as high-power transformers, are labelled in VA. Volt-amps are slightly different than watts for circuits that are highly reactive, that is are composed primarily of inductors (coils of wire around an iron or air core, typically- which include motors and transformers), and/or of capacitors (electrostatic devices which are used to store electrical charge and are used in filters for power supplies and other devices, among other purposes). When an AC voltage is placed across a reactive load, the resulting current flow is out of phase with the voltage. if the load is purely inductive, the current is 90 degrees negative out of phase with the applied voltage. If the load is purely capacitive, the current is 90 degrees positive with respect to the voltage.

    When this happens, you cannot simply multiply voltage and current to arrive at watts, since the two are not in phase. Instead, you will have a figure termed volt-amps. In order to calculate the watts draw for these types of loads, you need to know a figure called the power factor. In simplest terms, the power factor is the ratio of the voltage phase angle to the current phase angle (this is not exactly correct, but close enough for purposes of this discussion). For a purely resistive load with no reactive components, this figure will be exactly one. For all other loads, the result will be less than one. Unless you are dealing with highly reactive loads, however, you need not worry about power factor, and can simply multiply volts and amps and the resulting figure will reasonably closely approximate the actual power draw.

    The power company likes loads to have power factors as close to one as possible, since this reduces their costs for various reasons too technical to go into here. If you're really interested in this sort of thing, you can read this of just Google "power factor".

    Well, that'll teach you to ask a simple question!

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