izentrop wrote:but the energy consumed will be about the same.
Pretty much, I agree but it's about 1% or 10% close? This is the subject of my question: quantify this roughly ...
If the boiler return is + 10-15 ° C higher than the recommended one, I think that the boiler efficiency (decrease of the exchanges focus, increase of the temperature of the fumes) can well fall of 5% ...Should find some formulas or curves ...
5% on 2000L annual fuel oil, it is 100L and 300kg of CO2 ... enough to justify a regular cleaning not?
izentrop wrote:Only when the outside temperature is low and the insulation is poor, the starting temperature will have to increase and in this case, there will be overconsumption for a condensing boiler.
Actually with a condensing boiler and a return too hot, there is no condensation at all.
But the condensing boilers are, logically, recommended for low temperature circuits (floors, mus or heated ceilings ...) so without radiators to clean ...