As Engineering Supervisor at a New York elementary school, I have been doing research on boiler systems.  We all know that using a steam boiler system provides tons of benefits in limiting consumption while maintaining production.  I came across a company I had not heard much about, Miura (www.miuraboiler.com).  Have any of you heard of or use this brand?  I was most interested in their efficiency AFUE rating, small size, and production capabilities.  Their site also linked me to another interesting site which focused on using steam boilers in large industry buildings like schools and hospitals (www.steamboilersforhospitals.com).  As this is an important decision for my school, I was hoping I could get some feedback on efficient steam boilers someone else may be using, or their thoughts on Miura?  Thanks, look forward to your input...

We don't use steam in any of our commercial projects so I can't help, but you might try posting this to the geothermal forum.  I think there are some people there that have steam experience.

Bruce

Better yet, post it here:

http://www.boilerroom.com/forum.html

http://www.boilerroom.com/wwwboard/wwwboard4.html

Near as I can tell AFUE is nearly meaningless in most commercial & large facility apps, since system design and issues such as matching boilers to loads make a far greater impact on actual efficiency than a silly test around an arbitrary load-model. Assuming you have the boiler reasonably matched to the radiation, and the radiation is properly matched to the load, then it's all about the steady-state thermal efficiency of the boiler & distribution system. (I'm not a boiler engineer, not even close, but the system design & operation strategy is more important than any AFUE-type test number.

They're claiming steady-state thermal efficiencies in the low-mid 80s fuel-to-steam at the boiler output mid to high-80s in raw combustion effiency ((which may be close to theoretical limits? Seems VERY high for steam.) Getting it to operate near there in YOUR system surely involves real design. They must be relatively low mass at the heat exchange, since they're claiming ultra-fast startup times from cold-start. That has to help the average efficiency under partial load conditions and allow tighter control, lower overshoots, etc.

At least one poster on that forum ( dave canavarro) seems to like Miura boilers and has direct experience- you might email him for the particulars:

http://www.boilerroom.com/wwwboard/messages4/1934.shtml