Technologies

Comparing Boiler Efficiencies

Comparing Boiler Efficiencies Whether you are comparing the performance of different equipment or seeking to estimate your potential fuel savings, it is imperative to gain a basic understanding of how manufacturers perform efficiency tests and how test conditions differ from real-world operations. Unfortunately, efficiency ratings will generally not translate directly to fuel savings, because similar performance is rarely, if ever, consistently achieved in typical installations. The following material provides an overview of the standard test procedure and outlines key questions to ask as you...

Condensing Flue Gases

Water vapor, which is a by-product of the gas-fired combustion process, contains significant energy. For every pound of water vapor that is forced into a liquid state, some 1,000 BTU of latent energy, in the form of heat, are released. This change of state is called "condensing." Effective condensing increases the efficiency of the boilers and water heaters by about 10% – turning more of the unit's fuel into usable heat. What's more, condensing occurs naturally – when the vapors cool below their dew point, which is typically 135°F. By flowing cold water (<130°F) into the heat exchanger,...

Seasonal Performance

What Do We Mean by Seasonal Efficiency? Heating plant size is dictated by the total capacity needed to fully heat a building on the very coldest day or night in a given climate zone. However, such extreme weather is rarely experienced throughout the year. While a few winter days may come close to "design conditions" with boilers firing nonstop at 100% capacity, during warmer fall and spring days, far less demand is placed on the boiler plant to maintain building heat. To accurately predict the efficiency and operating cost of your system, it is critical to consider how frequently you...

Self-descaling Coil

Scale buildup and cracked heat exchangers significantly reduce – and prematurely end – the useful life of most water heaters. Scale buildup on the surface of the heat exchanger diminishes its ability to absorb and transfer heat. Cracked heat exchangers typically result from thermal shock caused by a rapid expansion or contraction of the material, brought on by sudden, drastic temperature changes. Rather than leave customers to fend for themselves with water softeners, chemical treatments, and extensive annual maintenance and protective procedures, AERCO indirect-fired* equipment has been...

Sub-cooling Steam

The helical coil design of our WaterWizard family of products achieves thermal efficiencies in excess of 90% and ultimately requires less steam to perform a given duty when compared to any other steam-to-water heat exchanger design. In addition, recovering more energy (BTU/hour) from each pound of steam, the equipment is engineered to "subcool" condensate and offers these additional advantages over conventional products: Flash loss is eliminated. Energy use is reduced by up to 15%. Cost of makeup feed water and treatment chemicals is reduced. Heat loss from condensate return piping can be...

The Importance of Modulation

In general, modulation refers to the ability to adjust a boiler's or water heater's firing rate (input) to meet the heating demand (output) of the system. AERCO equipment utilizes a fully modulating design that precisely matches firing rate to actual building demand. A 2000 MBH capacity Benchmark boiler can run with as little as 100,000 BTU/hr., or 6.7%, input. Drawing only enough fuel to meet actual load changes, each unit will gradually increase its capacity – in precise 1% increments – up to 100% capacity. Not only is less fuel burned as a result of modulating input, but also heat transfer...

Turndown vs. Valve Position

The Meaning of “Fire Rate” on the C-More Controller AERCO boilers and water heaters feature turndown ratios up to 30:1, the highest of which are unmatched in the marketplace – far exceeding the 3:1, 4:1, 5:1, 6:1, 8:1, and 10:1 capabilities of competitive units. Competitive boiler designs typically rely upon variable speed blowers and off-the-shelf gas valves to drive BTU/hr. input. In contrast, AERCO units feature a unique air/fuel delivery system, including patented gas plate designs, which support stable combustion control over a far greater range of operations. Sometimes, competitive...