Heat Output Difference Between Finned/Unfinned Rads?

[plumbandplumber]

As an approx percentage, how much less heat would a single panel non-finned rad give compared to one the same size with convecting fins?

Many thanks.

 

[albatross]

30% ish

 

[Ray Stafford]

It depends on what you are comparing.

To compare modern rads - look up the difference between a P1 and a K1 on [DLMURL="http://ukweb.stelrad.com/uk/resources/files/b9f4facf41064b974ee7dc716fd5ca26/elite.pdf"]this stelrad list[/DLMURL] Its a bigger difference than you would think.

Historically, this would be less. Originally, the fins were welded to the gaps between the waterways. When they shifted to welding them directly to the waterways, the output increased massively - IIRC it was about 15%.

 

[lame plumber]

It depends on what you are comparing.

To compare modern rads - look up the difference between a P1 and a K1 on [DLMURL="http://ukweb.stelrad.com/uk/resources/files/b9f4facf41064b974ee7dc716fd5ca26/elite.pdf"]this stelrad list[/DLMURL] Its a bigger difference than you would think.

Historically, this would be less. Originally, the fins were welded to the gaps between the waterways. When they shifted to welding them directly to the waterways, the output increased massively - IIRC it was about 15%.

need to rename you "Sheldon"

 

[plumbandplumber]

Thanks to you both.

Quite surprising to see the difference between finned and unfinned rads in that catalogue. Eg. a 600x1400 single goes from 3000BTU to almost 5000BTU just by welding on some fins.

 

[Howsie]

Surface area is king just like your guts.

 

[zzzjim]

This finned advantage may drop off with time ( 100s of dam spiders this year )

Is there a purpose made tool cleaning tool ?

 

[Howsie]

Yes. You can get them with or without bags.

 

[zzzjim]

Yes. You can get them with or without bags.

But who can find where attachments have gone !

( Drunkenly at m8s getting more heat from rad at XMAS , quietly late night with tissue and wooden dowel )

 

[Roger Welton]

This finned advantage may drop off with time ( 100s of dam spiders this year )

Is there a purpose made tool cleaning tool ?

Lots

https://www.google.co.uk/search?q=r...2&ie=UTF-8#q=radiator+cleaning+brush&tbm=shop

 

[doitmyself]

Surface area is king just like your guts.

The increase output due to the fins has nothing to do with the surface area. The channels improve the airflow over the rad surface, so the output due to convection increases.

 

[Howsie]

The increased surface area of the channels is what improves the air flow in the first place over all surfaces of the rad, including the fins.

Potato.

 

[doitmyself]

The increased surface area of the channels is what improves the air flow in the first place over all surfaces of the rad, including the fins.

No.

It's the fact that there are channels, which ensure that the airflow over the rad stays close to the heated surface. The size of the channel (cross section area), will be significant.

 

[Howsie]

And that the channel material conducts heat which is passed onto the air and speeds up the convection.

Yes.

 

[Ray Stafford]

Its both.

You can experiment, by taking a K1 and a P1 and mounting them sideways. You will get more output from the K1 because of the increased surface area, but only minimal convection.

However, your biggest change will come when you mount them the correct way up, as each convector column starts to work properly. The P1 will gain a bit, but the K1 will gain a lot.

Finally, the location of the fins on the waterways increased the temperature differential between rad and air - as the steel temp got closer to the water temp.

If you really want to maximise it - add a fan to make sure the air/steel temp differential stays as high as possible and that no "warm air blankets" form - oops, you have just invented a fan convector....

 

[zzzjim]

While we are getting all technical , does colour factor in at all ( ie white on back - less heat into wall ) Dark on front ?
( definitly NOT Chrome )

 

[Howsie]

Black radiates heat better better than white but it's a ting amount when compared to convection.

 

[Ermintrude]

Yes emissivity and absorption function of surface. Black body emitter best? Been a while.

 

[zzzjim]

Yes ......emissivity ...............

but is it going to make as much difference .. ie do we have lower flow , return temps than in the good old days
of cast iron monsters ?

 

[Ermintrude]

No about 1%

 

[Howsie]

Black radiates heat better better than white but it's a ting amount when compared to convection.

I must have been half asleep not to notice the spelling mistakes in that.

Should have read:

Black radiates heat better than white but it's a tiny amount when compared to convection.