Connect with us

Appliance Output per Hour

Discussion in 'Electronic Basics' started by ldbk, Dec 20, 2006.

Scroll to continue with content
  1. ldbk

    ldbk Guest

    Hi there- I'm hoping someone can help me. I'm thinking of purchasing
    a space heater with the following ratings

    Amps - 12.6
    Watts - 1500

    I'm trying to find out the kw/hr it puts out. I'm assuming the kw are
    1.5? When an appliance lists watts is it watts per hour? I'm not sure
    how I get that watts or kw/hr. Bottom line I'm trying to obtain an
    estimated cost per month of running this appliance 3 hrs/day, 7
    days/week. If someone can help me understand how to get to the kw/hr
    I'd really appreciate it!
  2. John  Larkin

    John Larkin Guest

    1500 watts is 1.5 kw. So every hour it uses 1.5 kwh (that's
    dimensionally kwh, kilowatts * hours, not kw/hr). If electricity costs
    you 10 cents per kwh, the heater will cost 15 cents per hour to run.

    Check your electric bill to see your local cost per kwh.

    Newspapers commonly refer to energy in kw/hr, because they all
    graduated from journalism school.


  3. They don't graduate, they run out of money. Then the school gives
    them a diploma to free up the seat for another paying customer.

    Service to my country? Been there, Done that, and I've got my DD214 to
    prove it.
    Member of DAV #85.

    Michael A. Terrell
    Central Florida
  4. John Fields

    John Fields Guest

    Yes. 'kilo' means "times 1000", so 1.5 kilowatts = 1.5kw * 1000 =
    1500 watts.
    Watts is the amount of work done in moving one coulomb's worth of
    charge from one place to another in one second, i.e, 1 watt = 1
    coulomb per second. So, a 1500 watt toaster burns 1500 coulombs per
    second every second it's on.
    Energy is measured in watt-hours, not kilowatts per hour, so to get
    how much energy you use you multiply the number of watts it uses
    times how long it's been on, and then multiply that by your utility
    company's rate.

    For example, your appliance uses 1500 watts, (1.5kw) so if your
    utility charges 10 cents per kilowatt hour, you'll be charged 15
    cents for every hour your appliance is on. 3 hours a day every day
    comes out to 90 hours for 30 day months, so at 15 cents per hour
    it'll cost you $13.50 a month to run the appliance.
  5. John Fields

    John Fields Guest

  6. ldbk

    ldbk Guest

    Thank you! No more "/" in kwh. I did not graduate from journalism
    school. :^)
  7. Gareth

    Gareth Guest

    Does this heater have a thermostat? If it does, it could cost a bit
    less since it may not actually be running all the time. Depends how
    cold it is and how well insulated the room is.


    PS if you really want to look like you know what you are talking about,
    it should be a capital W in kWh because watts are named after a person
    (James Watt)

  8. John  Larkin

    John Larkin Guest

    Sorry, but I don't care how I look.

  9. The watt or kilowatt is a measure of energy at an instant of time. Watt
    seconds, or joules, or kilowatt hours are a measure of power or work. You
    pay for power, not for energy. There is no such unit as kilowatts per hour!

  10. Get yourself a copy of "Dictionary of Quantities and Units" by J B Drazil
    (Pub = Leonard Hill, ISBN = 0 24944092). It is invaluable for this sort of

  11. John  Larkin

    John Larkin Guest

    You can't measure energy at an instant in time. Well, maybe potential
    energy. Energy is a time integral.
    Joules or kwh are measures of energy, not power. And you pay for
    energy, not for power.
    Kilowatts per hour is a legitimate engineering unit, but it's not

  12. jasen

    jasen Guest

    you've got work and power swapped round.

    It's only called a "power bill" colloquially,

  13. Gareth

    Gareth Guest


    I meant that for the OP's information. I wasn't intending to criticise
    your post, and I'm sorry if I gave that impression.

    I know that you know what you are talking about.

Ask a Question
Want to reply to this thread or ask your own question?
You'll need to choose a username for the site, which only take a couple of moments (here). After that, you can post your question and our members will help you out.
Electronics Point Logo
Continue to site
Quote of the day