Jake wrote:
kWh is power in Thousands of Watts, expressed over time.

I.E. 10 one hundred watt light bulbs consumes 1,000 watts. If you leave them
on an hour, you will pay for 1 kWh.

Watts are expressed as Amps x Volts.(for single phase, but let's not
complicate it further).

IE An air conditioner consuming 10 amps at 120 volts consumes 1,200 watts.
If you leave it on for an hour, you pay for 1.2 kWh.

The term "Watts" defines "True Power", and Turtle's explanation is correct.

5 amps x 240 volts = 1,200 watts
10 amps x 120 volts = 1,200 watts.

Same power input. If the circuit is designed correctly, the heat loss will
be nearly identical.

Hooking up a 240 volt unit should be less expensive, since it takes smaller
wire to do so. Yes, it takes smaller wire at 240 volts for the same "True
Power" to be delivered.

If, however, you're thinking about buying a window unit and just plugging
it into the nearest 120 volt outlet, please don't!!! You should have a
dedicated circuit for all but the smallest window air conditioner units. In
any event, please don't ever, ever, ever use an extension cord without
talking to an electrician first.

Hope this helps,

Jake


wrote in message
...

HvacTech2 wrote:


...what you pay for is power as in watts not amperage.

No. We pay for energy in kWh vs power in watts.

But maybe it's all Btus to you.

Nick




Hi,
Knit picking. True power is Watts x cosine Phi(power factor which is
always less than 1). You were talking about Volt x Amp. = Watts = True
power which produces energy + false power which is wasted. In real world
there is no electrical load which has power factor of 1.
The closer to 1, the higher efficiency.
Again the cosine Phi is the phase angle difference between V and I.
V is usually leading the I in real world inductive load.
Tony