Worth paying extra aluminium radiators?

[easyas123Viessmann]

The rate of flow of both the water and air are a factor but you could assume these to be equal for this example. You can look up the answer on pocket engineer urging the site is called.

 

[JohnD]

so your guess that an aluminium radiator can be a smaller size than a steel one is unquantified and unsupported by evidence.

We are, of course, talking about the amout of heat delivered to the room, which is the only thing that matters.

 

[mordim]

I really appreciate these sort of discussions, so it is good to waffle at times to come to some of conclusion.

My apologies for using the american spelling of Aluminium.

Aluminium Aluminium Aluminium, there better

So no definitive answer on heat output yet.

second issue, corrosion someone mentioned corrosion at the valves?

So realy that could be the use of the type of valves, pipework and not the rad itself.

So for a virtually corrosive free system you could use:

Brass
Aly Rads
PB pipework

At that stage would you need any inhibitor at all ever? and save on man hour costs there.

 

[easyas123Viessmann]

You are like a bull dog every time I give more reference you just say it's a guess but provide no defence for you own upon. As a direct comparison a single panel ally rad will give ten percent more out put than the same size double panel double convector rad according to a selection of manufactures charts on the net. Collect some evidence this time. Don't just claim you know better.

 

[JohnD]

I have not made any claims so I have nothing to prove.

you asserted that "a smaller rad can do the same job"

I have seen no evidence of that. Have you?

 

[easyas123Viessmann]

If an ally rad gives out ten percent more heat it would be ten percent smaller if sized by output. I can lead you to water but you just won't drink.

 

[JohnD]

"If"

 

[GasBod]

every rad no matter what material or size has a kw rating....simples

 

[Dan Robinson]

every rad no matter what material or size has a kw rating....simples

Yep, and those by the manufacturers are a little dubious too .

John....

I have not made any claims so I have nothing to prove.

you asserted that "a smaller rad can do the same job"

I have seen no evidence of that. Have you?

That is the biggest case of a pot calling the kettle black I have seen on the open forum in a long time.


If we have two materials of the same surface area, colour and mean temperature input; in the same environment.... how can their output be any different given the same energy input?

 

[easyas123Viessmann]

Why in heat exchange calculations are the conductive values of the materials used. The theory is similar to heat loss calculations for buildings. If your correct then why adjust the thermal conductivity of a structure under your analysis it will still lose the same amount of heat. I am not sure that the fundamentals of heating are being understood. Please try to provide some defence for your claims as I have. For example a heat loss calculation or heat exchanger design calculation that has no reference to the thermal conductivity or resistance of the material it is made from. Please think and study before commenting on an open forum. Poor knowledge can undermine the status of so called heating engineers when ignorance is so publicly displayed.

 

[JohnD]

If, as you assert, a radiator can be smaller for the same heat output if it is made of aluminium, let's see some independent results, per size and with the same amount of finning.

As far as I can see there is no discernable difference between the inside skin and the outside skin of a radiator filled with hot water. Heat transfer from water to metal is far faster than heat transfer from metal to air. The insulating properties of the metal skin are negligible. If the outside of the (thick) aluminium radiator and the (thin) steel radiator are the same temperature, there is no reason for the heat output into the room to differ.

 

[dhutch]

Sorry I can’t reply to this thread fully, I’m too busy being stunned by the *******s that is being put forwards as science...

...oh go on then, i'll add my threepence worth....

1 ) Steel rads work very well and give out heat cheaply and effectively.
2 ) Ali rads can potentially be extruded into slightly fancier and look more pretentious.
3 ) Neither will affect the efficiency of the system, the heat out will be closely matched to the total surface area of whatever rad you choose, both should out last you if you used a suitable inhibitor.


Daniel