Alright guys, I could do with the help of some you clever people here.
For one of my college assignments, I had to design 2 heating systems right from the beginning; working out U-values, heat loss calculations, selecting emitters, sizing emitters, pipe sizing etc.
I've been pretty successful with this however, when selecting the boiler I need to analyse how closely it matches the requirement. Therein lies my problem; I have designed my system on a DeltaT of 30 (60/40/20), the boiler I have selected (Vaillant Ecotec 618) states outputs for:
80/60: 3.8 - 18.5kw50/30: 4.2 - 19.3kw
My requirement is 18.5kw at 60/40, is there any way to work out what kind of output the boiler would produce at this flow/return temperature? Also, on another note, the heat input is stated as 18.6w..so when it is working at 50/30, it is over 100% efficient?!