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bikeman

Cardew said:

If you place in a room any type of electrical device, for the same amount of electrical energy consumed, the heat generated will be exactly the same.

So place in this room an electrically heated radiator, a fan heater, light bulbs, an electric iron, a fridge, vacuum cleaner, a TV, a radio, toaster, an electric motor, siren, speakers etc etc. if they each consume, say, 1kWh then they will all produce EXACTLY the same amount of heat.

What utter nonsense. You are embarrassing yourself and showing a fundamental lack of understanding.

I'll give you a clue, the law of thermodynanics applies only to isolated systems, which your examples are not, and whilst it says that energy can be neither created nor destroyed, it does not preclude that it can be transformed from one form to another.

It is clear to everone else, except you, that the household objects that you list are not all designed to convert energy to heat, some convert that energy to sound, motion etc.

QrizB

bikeman said:

It is clear to everone else, except you, that the household objects that you list are not all designed to convert energy to heat, some convert that energy to sound, motion etc.

What do you think happens to the energy when the sound is absorbed, when the motion stops, etc?

[Deleted User]

bikeman said:

Cardew said:

If you place in a room any type of electrical device, for the same amount of electrical energy consumed, the heat generated will be exactly the same.

So place in this room an electrically heated radiator, a fan heater, light bulbs, an electric iron, a fridge, vacuum cleaner, a TV, a radio, toaster, an electric motor, siren, speakers etc etc. if they each consume, say, 1kWh then they will all produce EXACTLY the same amount of heat.

What utter nonsense. You are embarrassing yourself and showing a fundamental lack of understanding.

I'll give you a clue, the law of thermodynanics applies only to isolated systems, which your examples are not, and whilst it says that energy can be neither created nor destroyed, it does not preclude that it can be transformed from one form to another.

It is clear to everone else, except you, that the household objects that you list are not all designed to convert energy to heat, some convert that energy to sound, motion etc.

It is really hard not to get personal when you make statements like that but I won't. I've got a degree in Physics and I fully understand this topic.

Yes, energy is not created or destroyed, it is converted, but in most scenarios, it ends up as heat energy rather than any other form. Light, sound, and motion will all end up converting to heat fairly soon except in unusual situations such as in vacuums. 

Let's say electrical energy is converted to a motion (kinetic energy), for example, say a fan spinning around. When you switch it off, it doesn't carry on spinning - because of friction in the bearings and the air it is trying to move and that friction is transferring kinetic energy into thermal energy. The air that blows out of the fan doesn't carry on forever, the kinetic energy in that air is ultimately converted to thermal energy due to friction between air molecules.

If the fan had a frictionless bearing and operated in a vacuum then it would carry on spinning forever after the electricity was switched off - the kinetic energy would be preserved forever.

I'd be interested to see how you explain where all the electrical energy put into my TV ends up conserved as, eg is it kinetic, chemical, electrical, thermal etc? 

Cardew

bikeman said:

Cardew said:

If you place in a room any type of electrical device, for the same amount of electrical energy consumed, the heat generated will be exactly the same.

So place in this room an electrically heated radiator, a fan heater, light bulbs, an electric iron, a fridge, vacuum cleaner, a TV, a radio, toaster, an electric motor, siren, speakers etc etc. if they each consume, say, 1kWh then they will all produce EXACTLY the same amount of heat.

What utter nonsense. You are embarrassing yourself and showing a fundamental lack of understanding.

I'll give you a clue, the law of thermodynanics applies only to isolated systems, which your examples are not, and whilst it says that energy can be neither created nor destroyed, it does not preclude that it can be transformed from one form to another.

It is clear to everone else, except you, that the household objects that you list are not all designed to convert energy to heat, some convert that energy to sound, motion etc.

Well I am a chartered electrical engineer. However I must conceed I studied many years ago and hadn't appreciated that the law of thermodynamics had changed in recent years and now only applies to isolated systems.

After further research I have discovered to my amazement that devices like a siren were designed to produce noise and not heat a room; so thank you for putting me on the right track in such a gentle manner. 

jak22

Ive also learned that as an annoying side effect of producing heat - very welcome in our recent Summer - my light bulbs are converting some of the energy into light - but thankfully that's temporary as all that waste light is converted back into useful heat to get back to the 100% inefficiency. 

bikeman

Deleted_User said:

bikeman said:

Cardew said:

If you place in a room any type of electrical device, for the same amount of electrical energy consumed, the heat generated will be exactly the same.

So place in this room an electrically heated radiator, a fan heater, light bulbs, an electric iron, a fridge, vacuum cleaner, a TV, a radio, toaster, an electric motor, siren, speakers etc etc. if they each consume, say, 1kWh then they will all produce EXACTLY the same amount of heat.

What utter nonsense. You are embarrassing yourself and showing a fundamental lack of understanding.

I'll give you a clue, the law of thermodynanics applies only to isolated systems, which your examples are not, and whilst it says that energy can be neither created nor destroyed, it does not preclude that it can be transformed from one form to another.

It is clear to everone else, except you, that the household objects that you list are not all designed to convert energy to heat, some convert that energy to sound, motion etc.

Yes, energy is not created or destroyed, it is converted, but in most scenarios, it ends up as heat energy rather than any other form. Light, sound, and motion will all end up converting to heat fairly soon except in unusual situations such as in vacuums. 

I just tested your theory with a bunch of fans and low and behold they cooled the room. I expect all that kinetic energy was heating up the bearings and air molecules but nope the room stayed cool no matter how long I left them on.

bikeman

Cardew said:

bikeman said:

Cardew said:

If you place in a room any type of electrical device, for the same amount of electrical energy consumed, the heat generated will be exactly the same.

So place in this room an electrically heated radiator, a fan heater, light bulbs, an electric iron, a fridge, vacuum cleaner, a TV, a radio, toaster, an electric motor, siren, speakers etc etc. if they each consume, say, 1kWh then they will all produce EXACTLY the same amount of heat.

What utter nonsense. You are embarrassing yourself and showing a fundamental lack of understanding.

I'll give you a clue, the law of thermodynanics applies only to isolated systems, which your examples are not, and whilst it says that energy can be neither created nor destroyed, it does not preclude that it can be transformed from one form to another.

It is clear to everone else, except you, that the household objects that you list are not all designed to convert energy to heat, some convert that energy to sound, motion etc.

Well I am a chartered electrical engineer. However I must conceed I studied many years ago and hadn't appreciated that the law of thermodynamics had changed in recent years and now only applies to isolated systems.

After further research I have discovered to my amazement that devices like a siren were designed to produce noise and not heat a room; so thank you for putting me on the right track in such a gentle manner. 

So your siren's primary function is to convert electrical energy into sound, only a small part of frictional losses is converted to heat. Therefore not all of the energy it consumes is being converted to heat.

Your assertion that all machnes comsuming the same energy will produce exactly the same amount of heat - this is clearly wrong.

[Deleted User]

bikeman said:

Cardew said:

bikeman said:

Cardew said:

If you place in a room any type of electrical device, for the same amount of electrical energy consumed, the heat generated will be exactly the same.

So place in this room an electrically heated radiator, a fan heater, light bulbs, an electric iron, a fridge, vacuum cleaner, a TV, a radio, toaster, an electric motor, siren, speakers etc etc. if they each consume, say, 1kWh then they will all produce EXACTLY the same amount of heat.

What utter nonsense. You are embarrassing yourself and showing a fundamental lack of understanding.

I'll give you a clue, the law of thermodynanics applies only to isolated systems, which your examples are not, and whilst it says that energy can be neither created nor destroyed, it does not preclude that it can be transformed from one form to another.

It is clear to everone else, except you, that the household objects that you list are not all designed to convert energy to heat, some convert that energy to sound, motion etc.

Well I am a chartered electrical engineer. However I must conceed I studied many years ago and hadn't appreciated that the law of thermodynamics had changed in recent years and now only applies to isolated systems.

After further research I have discovered to my amazement that devices like a siren were designed to produce noise and not heat a room; so thank you for putting me on the right track in such a gentle manner. 

So your siren's primary function is to convert electrical energy into sound, only a small part of frictional losses is converted to heat. Therefore not all of the energy it consumes is being converted to heat.

Your assertion that all machnes comsuming the same energy will produce exactly the same amount of heat - this is clearly wrong.

In the universal sense they are correct. The sound waves eventually get absorbed or dissipate in a material, raising the energy of that material. 

I wouldn’t suggest using the heat death of the universe for space heating though.

QrizB

bikeman said:

I just tested your theory with a bunch of fans and low and behold they cooled the room. I expect all that kinetic energy was heating up the bearings and air molecules but nope the room stayed cool no matter how long I left them on.

Evidence, please, with calibrated equipment and ideally a peer-reviewed report. You won't get your Nobel prize without it.
Otherwise, well, I don't believe you.

Ultrasonic

bikeman said:

I just tested your theory with a bunch of fans and low and behold they cooled the room. I expect all that kinetic energy was heating up the bearings and air molecules but nope the room stayed cool no matter how long I left them on.

The moving air blowing over your skin may have made you cooler but they categorically didn't make the room cooler. Simply feeling over where the motor in the fans are should tell you that he opposite is true.

(Another physicist passing though. This discussion actually reminds me of a university interview question I had when applying to be an undergraduate - they offered me a place.)