Question about wattage ratings.

Energize · 19 May 2006 at 19:32

If say a shower is rated at 10.5 Kw does this means it uses 10.5Kw an hour? We're trying to work out why the electricity bill is so high.

ricky1981 · 19 May 2006 at 19:41

It means its power is 10.5kW, in an hour it would user 10.5kWh (kilowatt hours). 10.5 is quite a lot but you'd need be taking pretty long showers for it to really build up.

Mark A · 19 May 2006 at 19:43

Plus that figure is probably at its highest setting?.

Mark

Adam_151 · 19 May 2006 at 20:13

Mark A said:
Plus that figure is probably at its highest setting?.

Mark

That would be true, but a shower generally only has one or two power settings, the control dial that you use to set the temperature just controls the flow rate of water through the heater can (same amount of power + less water = hotter water), the dial that is on some showers that has full on, ecconomny, cold and off does adjust power taken though (it shuts off one of the heating elements in the heater can when on eccomo mode)

Energize · 19 May 2006 at 21:14

All it has is one dial for temperature (crap I know), I was wondering is there a chance that it uses more than 10.5kw due to it not being 100% efficent like computer power supplies do?

singist · 19 May 2006 at 21:17

more likely it's the heating and lighting for those "plants" you're cultivating ..

Burnsy2023 · 19 May 2006 at 22:19

Energize said:
All it has is one dial for temperature (crap I know), I was wondering is there a chance that it uses more than 10.5kw due to it not being 100% efficent like computer power supplies do?

It won't consume any more than 10.5KW. The figure is it's maximum power usage at full power.

Burnsy

Aod · 19 May 2006 at 22:45

i'm not really sure, but watt figures are usually watts per second or something? i'm sure that calculations for power involving watts and time, its measured in by the second.

p4radox · 19 May 2006 at 22:50

Watts is a measure of power - which is the rate of expenditure of energy. 1 Watt = 1 Joule per second. you pay for energy in Kilowatt hours, so if that shower was on for an hour it would cost you 10.5 KWhours.

The shower would probably always be at the same power, the temperature is usually altered by changing the flow of the water - the faster the flow the lower the temperature of the water coming out.

Energize · 19 May 2006 at 23:07

burnsy2023 said:
It won't consume any more than 10.5KW. The figure is it's maximum power usage at full power.

Burnsy

Why is it different for computer power supplies then? They can be rated at 500watts but use 600 because of only being 80% efficent.

Burnsy2023 · 19 May 2006 at 23:33

Energize said:
Why is it different for computer power supplies then? They can be rated at 500watts but use 600 because of only being 80% efficent.

Beacuse its a heating element and works on 230V~ and doesn't need any step down transformers to bring the voltage down to the needs of a pc (+-5v, +-12v etc). Which is why they are only 80% efficient as they need to charge the coils in the transformer.

Burnsy

Swanster · 19 May 2006 at 23:38

Energize said:
Why is it different for computer power supplies then? They can be rated at 500watts but use 600 because of only being 80% efficent.

When a shower is rated at 10.5kw, it means that's much power it needs to work. For a psu, it means how much power it is able to supply to the computer.