Best Condesing Boiler

HydroMan

I'm looking at a few high efficiency mod-con boilers for commercial application. I need between 1,000MBH and 2,000MBH, and would like to pipe variable-primary instead of primary/secondary. Any thoughts or recommendations on which boilers, maybe even a Top 3, you would choose?

CMadatMe

Alot of Variables

That's a pretty umbrella question your asking. My first look would be at the Viessmann Vitodens 200 on a rack system or a Vitocrossal. But reality might send me elsewhere. If money is no object then the Vitocrossal with a Weishaupt burner is the best in my opinion hands down. 98% AFUE in a single boiler that would easily do your 2mil. If redundancy then 2 smaller ones.

http://www.viessmann-us.com/etc/medialib/internet-ca/pdfs/commercial.Par.56572.File.File.tmp/Vitocrossal_300_TDM.pdf

SpeyFitter

Cleaver-Brooks

I'd have a look at a Cleaver-Brooks Clearfire Condensing Boiler (Model CFC). This boiler has a 316 Titanium Stabilized downfiring fire tube heat exchanger for a lower head loss than many competing models (aka less pump power required).  Their boilers have a 5 to 1 turn down if I'm not mistaken, and they have 500 MBH, 750 MBH, 1000 MBH, 1500 MBH, 1800 MBH and 2500 MBH models.  If I were you, I'd consider redundancy by picking 2 or 3 smaller boilers instead of 1 larger boiler. This will give you a higher turn down ratio by teaming up the boilers to act as one, and if one should fail, you have some heat at the very least due to the redundancy.