BTU output of 1 1/4 copper

charliechicago

Hello to all,
I'm sizing a replacement STEAM boiler and wanted to know the BTU output of a 1 1/4 inch finned copper "radiator". Anyone know?
Thanks!
Michael.

Jamie Hall

How big are the fins? Spacing?

charliechicago

Not sure, will get back to you soon with info.
Thanks.

EdTheHeaterMan

Here is one brand that may get you close. Look at the ST 1200-3A at around 210° or somewhere between 210° and 220°



this is what it looks like. if your emitters are similar, then this will be close enough.



There are other configurations of 1-1/4 copper elements at this manufacturer web site
https://www.haydoncorp.com/catalog/category/commercial-baseboard

Yours truly,
Mr.Ed

charliechicago

Thanks

Alan (California Radiant) Forbes

Some more information here:

https://www.slantfin.com/wp-content/uploads/2016/04/Fin-Tube-Selection-Guide-820.pdf

mattmia2

Isn't knowing what sort of cabinet it is in and the pitch of the fins important here? So a picture would be good.

charliechicago

I’ll get a picture too. 

charliechicago

The fins are 5 per square inch.
They are 3 by 3.5

Jamie Hall

You can come reasonably close to the EDR if you remember that EDR is actually a measure of the effective radiating surface area.

So... each fin has about 10.5 square inches on each side, or 21 square inches per fin, but you need to subtract the area of the hole for the pipe -- a bit less than 2 square inches. But then add the surface area of the pipe between fins. And call it 20 square inches per fin. And you have 5 fins per inch length of pipe (I think that's what you meant to say). So call it 100 square inches per inch, or 1200 square inches per foot of pipe. So... a very close approximation of the EDR would be 8 for each foot of finned pipe.

charliechicago

Wow, thanks.
So if I have 86 feet of this piping I come out with 165,120 BTU?
86 times 8 times 240.

Jamie Hall

Looks about right -- always assuming that the air can circulate over those fins.