Boiler efficiency...

Jamie Hall

To satisfy my curiousity, are there data available for modulating gas boilers for the efficiency of a properly tuned boiler at various turn down levels? I saw a set of graphs recently for various return water temperatures, but did that also have various firing rates? Can someone point me to a source?

HVACNUT

I'm not sure theres anything that specific. A lot of manufacturers want separate tests at low and high fire within their parameters.

SuperJ

I'm doing a commercial job with 10 Aerco boilers in parallel.
Benchmark Platinum 6000's. Basically you want to run as many boilers as you can at as low a fire rate as possible for max efficiency.

http://aerco.com/sites/default/files/document/document/BMK 5000 Efficiency Curves.pdf

RayWohlfarth

@SuperJ I saw where Weil Mclain does that as well Not sure if it really saves as much as one boiler running while other is isolated
@Jamie Hall Here is a pic from PK Boilers where they show the various firing rates at different return temps

Jamie Hall

Perfect! Thanks guys -- exactly what I was looking for. Off for some more rumination here...