B How do I convert kW to kWh for my project involving a heat exchanger?

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To convert kW to kWh, it's important to understand that 1 kW running for 1 hour equals 1 kWh, while 60 W running for 1 hour equals 60 Wh, not kWh. The confusion arises from mixing energy and power units; kWh is a measure of energy, while kW is a measure of power. When converting energy units, 1 kWh is equivalent to 3412 BTU, which is commonly used in the U.S. Additionally, it's noted that a Joule is a Watt-second, and thus kWh can be converted to kJ by multiplying by 3600. Understanding these conversions is crucial for accurately reporting energy usage in projects involving heat exchangers.
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Say I have a 60W device.

I know running for one hour it uses 60 W x 3600 s = 216 kJ of energy.

Does that mean it uses 216 kWh of energy?

Or does kWh means 60 W x 1 hour = 60 kWh?

I am confused because the units in 60 kWh is not in their simplified terms.

More specifically, this pertains to a project that I am working on.
From experimental values, I found that with X kg/s of water flowing through the heat exchanger and some temperature increase, I can find the power of the heat exchanger in kW.
I would like to provide the values in BTU since that is just what people still use in the States.
I realized BTU is an energy unit, not power, and 1 kWh = 3412 BTU.
So I need to convert kW to kWh.
 
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FQVBSina said:
Or does kWh means 60 W x 1 hour = 60 kWh?

you have a k in there that you shouldn't

60 W x 1 hour = 60 Wh

FQVBSina said:
So I need to convert kW to kWh.

so going from what I wrote above

a 1kW heater running for 1 hour = 1kWh
 
davenn said:
you have a k in there that you shouldn't

60 W x 1 hour = 60 Wh
so going from what I wrote above

a 1kW heater running for 1 hour = 1kWh
Alright, thanks! I thought kWh is basically kJ. I guess kWh needs to convert by a factor of 3600 before it becomes kJ then.
 
FQVBSina said:
More specifically, this pertains to a project that I am working on.
From experimental values, I found that with X kg/s of water flowing through the heat exchanger and some temperature increase, I can find the power of the heat exchanger in kW.

Yes that's possible/correct.

I would like to provide the values in BTU since that is just what people still use in the States.

I believe they actually use BTU/h (BTU per hour) but the "h" is sometimes omitted (bad practice).

So you just need to use..

1 kW = 3412 BTU/hr
 
FQVBSina said:
Alright, thanks! I thought kWh is basically kJ. I guess kWh needs to convert by a factor of 3600 before it becomes kJ then.
One thing worth remembering: a Joule is a Wattsecond.
So 3600 J = 3600 W s = 1 W h = 0.001 kW h .
 
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