Quote Originally Posted by MannyCalavera View Post
Excellent cheese.

From a "green" and efficient point of view, and if one accepts that fuel oil will always be burned en mass (more or less), the highest COP choice would seem to be the most logical. I guess if i were to start writing a report in it now (which i aint, dont worry) the objective would read

"Heat pump feasibility: investigation into significantly increasing air pre-heat temperatures using a heat pump to recover energy and boost the thermal quality of the hot water loop and therefore glycol runaround".

I just read - you are thinking of another setup? I suppose there will be a whole range of different options. In terms of utilising exhaust air, i dont think that's worth looking into - far away from glycol unit, high up, exhaust stack, all sorts of pish.
The air is an option, and you could use a stacked packed tower, but no I have not gone down this track.
Just better use of the energy available.
Your feasability statement would be incorrect.
"Heat pump feasibility: investigation into significantly increasing air pre-heat temperatures using a heat pump to recover energy"
would read correctly

I have given you all you need to come up with the process (just not in a single description) Giving you the direct answer does not help you learn (An argument i have with my wife when doing the kids homework, learn the method, not just the answer)
I will give you a clue, start with the air (even though I think your figures are wrong)and work backwards.
Keep up the good work, look at the process not the individual parts.