HEATING SYSTEM ADDITIVE STATED TO IMPROVE SYSTEM EFFICIENCY AND SAVE APPROX. 15% ON GAS BILLS

[johnduffell]

The other thing that occurred to me is that efficiency doesn't have a single meaning in science. It's very abstract in the same way that "percentages" or even "numbers" are.
So you could indeed improve the"efficiency" of a radiator or other heat exchanger by 15% (eg by directing a fan over it) but that would be efficiency of heat transfer between the fluids, not efficiency of turning gas into usable heat.

I suspect the technical department proved the former, and the marketing department wrote the latter.

 

[Ric2013]

I remember reading some QRL (Quinn Radiators LTD) literature in which they claimed their new radiator was more efficient: the small print showed that the new radiator was more efficient in terms of heat output per lb of steel used in the manufacture of the radiator (and therefore the newer design of radiator had less embodied energy for a given heat output), compared with the standard design. By that yardstick, re-using an old radiator would have been even more 'efficient'.
What we really are interested in in terms of efficiency is getting the maximum thermal comfort (minimum percentage of people dissatisfied with the room temperature) for the least possible amount of gas.

 

[fixitflav]

I remember reading some QRL (Quinn Radiators LTD) literature in which they claimed their new radiator was more efficient: the small print showed that the new radiator was more efficient in terms of heat output per lb of steel used in the manufacture of the radiator (and therefore the newer design of radiator had less embodied energy for a given heat output), compared with the standard design. By that yardstick, re-using an old radiator would have been even more 'efficient'.
What we really are interested in in terms of efficiency is getting the maximum thermal comfort (minimum percentage of people dissatisfied with the room temperature) for the least possible amount of gas.

As johnduffell said, it's worth making sure what somebody means by efficiency.
And if the higher heat output per kg of steel is achieved by using thinner steel hence shorter rad life, overall there might be no improvement