What is a Kilowatt hour?

[David in London]

Dear All,

I am trying to figure out what my electric heater is costing me per hour to run.

My Heater is a 4800 watt 30 amp 220 unit. I pay 7.39 cents per kilowatt hour.

Can someone please walk me through the math here,

Thanks,

David.

[Mike Harris, London]

Hi Dave

Here's the formula:

kWh=(power(W) x time(h)) divided by 1000

Cost= kWh x 7.39

The product is in cents not dollars, your heater is costing about 70 cents an hour to run.

Hope this Helps
Mike

Mike

[Gary in Niagara]

Mike you had better check your math.

(W x time)/1000 = (4800 x 1) /1000 = 4.8 KWh to run the heater 1 hour

cost = KWh x 7.39 = 4.8 x 7.39 = 35.472 cents per hour(when the heater runs the full hour).

[Mike Harris, London]

[William Young]

Gary; Thanks for that formula. Guess Kootenay Power is right when they advertise the lowest rate in Canada. My rate is 5.27. I use that same construction heater in my shop and if my math is right that should be 25.296 cents an hour.
W.Y.

[Mike from Milton]

The water heater does not of course run 100% of the time. I don't have the time right now to look up he conversion factors, but you can figure out the calories required to raise the temperature from about 50 degrees F to 120 degrees F (after converting to C and KW) and then estimating the radiant loss. The total cost is the combination factor of both. If you have teenagers automatically multiply all calculations by 2 for each one! I put extra insulation around my water heater 25 years ago when the first energy crunch hit, and I know it paid off.

A kilowatt hour hour is simply 1000 watts for one hour.