Thanks for straightening me out on that low temperature efficiency thing. I sort of wondered about it after I wrote the comment, and what I'd said I realized didn't quite make sense. What you get for letting a steam guy talk about mod/cons, I guess.
I still wonder sometimes about figuring out a SIMPLE way to use a stack gas to return condensate heat exchanger to pick up some efficiency on steam systems -- it's what is done on power boilers, after all -- but everything I think of is so Heath Robinson that I just forget about it...
Anyway, thank you again -- I really appreciate it.
You're quite welcome Jamie. I didn’t mean to come off abrasive. Posts like that one always lead into an underlying circumstance as you saw. The fellow really can’t do a whole lot with out dialing in his ODR first, and then it is what it is. Unless he adds more emitter, or wants to sacrifice comfort. He really can’t run a 45 delta across the boiler, and run baseboard in that flow rate.
This whole higher gpm equals higher output is a bit of a quandary. As you saw in Rays post about his system not coming up to temp on commissioning until he reduced flow rate.
If we really extrapolate the hydronic formula we know that things become unrealistic yet they work out per the formula.
The GPM of condensate is really small. Without a large delta T there’s not much there without a very low approach heat exchanger, which would require an inducred draft. Best you’ll accomplish is gaining a fraction of a percent.
Only way to increase steam efficiency is go with a deep vacuum system.