Why difference in BTU for radiators of same size?

[Possom]

I noticed two different brands of 3-column radiators which are both of the same 1800mm x 470mm size.

https://www.bigbathroomshop.co.uk/m...n-radiator-1800mm-x-470mm-triple-column-59378
5193 BTU at Delta T50


https://www.radiatoroutlet.co.uk/18...quered-vertical-traditional-3-column-radiator
8218 BTU at Delta T50

Is it possible that two 3-column rads of the same size would genuinely have such a discrepancy in the BTU output when measured at the same Delta T? If this is genuinely possible, why is it that there would be such a discrepancy e.g. the material the rad is constructed from or the manufacturing process, or some additional design feature?

Thanks.

 

[denso13]

Hard to say. Apologies if I'm missing it but I cant see Delta T50 mentioned on the bottom link.

 

[Possom]

Apologies if I'm missing it but I cant see Delta T50 mentioned on the bottom link.

It doesn't appear to be stated on the webpage though that's what I was informed when I contacted them.

 

[denso13]

At Delta T65 the top one is 7400 BTU's making the bottom one 10% (ish) higher. The bottom one does claim they are 10% higher in some instances due to heavier materials.

Just a thought.