Edit: Rads returns should be 60C, with 70C boiler temp, (I copied wrong cell) but calcs are basically quite correct.
DHW sheet attached
Actually I see that there are rads in the above system so I just inputted a few numbers in my spreadsheet which may (or may not) be interesting.
Assuming UFH demand only of 10kw only requires a boiler circ pump flowrate of 4.48LPM@70C, this means the boiler will run with a dT of 32C, maybe problematic for some makes?. the only other remarkable is if the boiler temp is either reduced to 45C or the point that you are all making, that it has fired up from cold and hasn't become > 45C so the boiler pump circ rate would have to be 44.4LPM v/vs 28.4LPM with boiler temp at 70C (all 3 systems calling), hence the slow cyl warm up time or whatever?.
DHW sheet attached
Actually I see that there are rads in the above system so I just inputted a few numbers in my spreadsheet which may (or may not) be interesting.
Assuming UFH demand only of 10kw only requires a boiler circ pump flowrate of 4.48LPM@70C, this means the boiler will run with a dT of 32C, maybe problematic for some makes?. the only other remarkable is if the boiler temp is either reduced to 45C or the point that you are all making, that it has fired up from cold and hasn't become > 45C so the boiler pump circ rate would have to be 44.4LPM v/vs 28.4LPM with boiler temp at 70C (all 3 systems calling), hence the slow cyl warm up time or whatever?.
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