When specifying and designing a high-efficiency boiler system, much attention is often given to the published efficiency ratings of units. However, it should not be the end-all in making that decision. There are several other factors that go into selecting the best boiler for optimal operation year-round to achieve the greatest return on investment (ROI). Doing so will also help improve maintenance schedules and life of the boiler system.
Plumbing engineers need to recognize how boiler efficiency ratings are determined. In an attempt to create a level playing field, industry standards were established based on certain criteria. These included a 30-minute heat soak, continuous firing at 100% of capacity and 80°F feed water.