Boilers are defined by the American Society of Heating, Refrigerating and Air Conditioning Engineers (ASHRAE) as ‘a self-contained low-pressure appliance for supplying steam or hot water’, and in this article we’ll be discussing boilers that provide hot water for building space heating. This is one area of HVAC equipment that has come a long way in terms of efficiency.

Traditionally, boiler design required operation without condensing the flue gas in the boiler to prevent corrosion of the internal components. Hot-water boilers were operated at around 140°F minimum water temperature to prevent corrosion and reduce thermal shock. But the lower the water temperature, the more efficient the boiler becomes… condensation and all, that’s the way current manufacturers are moving. Full condensing boilers are now capable of operating at 98% thermal efficiency.

With those impressive improvements come increasingly stringent minimum efficiency requirements as dictated by ANSI/ASHRAE/IESNA Standard 90.1 – Energy Standard for Buildings Except Low-Rise Residential Buildings. Standard 90.1-2004 minimum thermal efficiency requirement listed for a gas-fired boiler (≥300,000 Btu/h and ≤2,500,000 Btu/h) was 75%. In the 2007 version of the standard, this minimum efficiency was increased to 80% thermal efficiency after 3/2/2010.

The 1,500 MBh AERCO Benchmark Low NOx Boiler can help reduce installation and lifecycle costs while delivering energy efficiency, quiet acoustics and easy maintenance – all in a small (28" W x 36" L x 79" H) footprint.

Ultimately the greatest asset of this product is its energy efficiency, through which it reduces environmental and economic impacts associated with energy usage. According to AHRI/IBR test data, the Aerco BMK 1.5 LN operates at a combustion efficiency of 93.9% with a thermal efficiency of 91.9% and delivers 20:1 burner turndown to match energy input based on system load to yield the highest possible efficiency. Coupled with high efficiencies, this high turndown ratio minimizes cycling losses and wasted energy.

The materials are advanced as well; the heat exchanger is designed to withstand thermal shock, and eliminates the need for boiler pumping equipment. Their forced draft, modulating burners operate with unmatched turndown to minimize cycling and maximize seasonal efficiency while simplifying the venting system. And all the adhesives, sealants paints and insulation used in the manufacturing of AERCO’s boilers is low-emitting and meets VOC limits established by Green Seal Standards and Green Guard.

Removable enclosure panels support easy access to all piping and simplify lifetime maintenance. And finally, the BMK minimizes emissions with a <16 ppm low-NOx burner (compared to typical low-NOx applications of <30 ppm).

 

Related Products:

• ConsERV: Energy Recovery Ventilator



• ClearEdge Power Fuel Cell Technology