I am working with a property that has a 2 year old EGH-125. It is connected to a Moline system, which is by definition, fully orificed. The boiler fires at 495,000 BTU and ideally we would be firing at 299,000 to 334,000 BTU, assuming 82% efficiency.
My question, mainly to the pros on here, is to what extent can the current issue of the EGH (with baffles) be downfired? I was under the impression, that the old issue, the EGH-12 without baffles, would lose a great deal of efficiency if the firing rate was turned down. But, then WM down fired the boiler, added baffles, and increased the efficiency by a point or 2. Any insight would be greatly appreciated.
Dave in Quad Cities, America
Weil-McLain 680 with Riello 2-stage burner, December 2012. Firing rate=375MBH Low, 690MBH Hi.
System = Early Dunham 2-pipe Vacuo-Vapor (inlet and outlet both at bottom of radiators) Traps are Dunham #2 rebuilt w. Barnes-Jones Cage Units, Dunham-Bush 1E, Mepco 1E, and Armstrong TS-2. All valves haveTunstall orifices sized at 8 oz.
Current connected load EDR= 1,259 sq ft, Original system EDR = 2,100 sq ft Vaporstat, 13 oz cutout, 4 oz cutin - Temp. control Tekmar 279.http://grandviewdavenport.com