With all this talk about potentially switching from gas to hydrogen or even blending some hydrogen into the gas, does anyone know how this affects the dew point of the products of combustion? With natural gas I think it starts to condense around 57C or so, so the return temperature needs to be under that to get significant condensing in a modern boiler. If the gas was blended with say 10% hydrogen, does it change that temperature? Actually it would be nice to see a chart going from 0% 10%, 20% *** 100% hydrogen. Has anyone seen such a chart?