Used Boilers Key Terms

Understanding a few key terms will benefit you in your purchase of a refurbished boiler unit

By Loraine Degraff, Freelance Writer/Playwright

Boilers are used to heat air and water in homes and commercial buildings. They come in a variety of models and sizes and are designed with several energy-saving features. Most units are also environmentally friendly. Due to the ever increasing costs of raw materials, refurbished or used boilers are becoming a popular option for consumers today. Some used boilers can be reconstructed and returned to service for as little as 30% of the cost of a new unit. Many boiler manufacturers have recognized the value of adding refurbished units to their line of new products. Whether you are interested in purchasing a new or refurbished unit, understanding a few key terms will certainly be beneficial.

Steaming rate

The rate at which a boiler produces steam is called the steaming rate. This rate is usually expressed in terms of pounds per hour or kilograms per hour. A refurbished power boiler may supply about 320,000 pounds per hour of steam to generate a combined 65 megawatts of electricity.
Try: For more on steaming rate, go to Process Heating.

Condensing boiler

Unlike conventional boilers, a condensing boiler operates with infinitely variable temperature while utilizing the condensation heat contained in the flue gas. The condensing boiler cools the flue gases in such a way that the water vapor contained in the gas condenses. Used gas condensing boilers cost a little more than their non-condensing counterparts, but they do last longer when properly installed and maintained.
Try: For a description of a condensing boiler, go to The Encyclopedia of Alternative Energy and Sustainable Living.

AFUE

The Annual Fuel Utilization Efficiency rating is commonly used by all manufacturers of boilers. This rating measures how much the heat delivered to your house compares to the amount of fuel that is supplied to your heating appliance. Consumers can benefit from understanding this rating to compare the efficiency of different heating appliances, including used boilers.
Try: For an explanation of AFUE, go to Energy Kinetics.

Geothermal heating

Geothermal heating is the direct use by heating appliances of geothermal power. Geothermal power is produced from heat stored in the earth. Manufacturers of refurbished boilers are exploring the use of geothermal heating as a means of producing an eco-friendly product.
Try: Read more about geothermal heating at BoilersPrice.com.

Aquastats

An aquastat is a device used to control water temperature in hydrolic heating systems such as boilers. The aquastat uses a sensing bulb that is placed in boiler to determine the set temperature of the water. Aquastats should be tested for functionality before being replaced in refurbished units.
Try: FurnaceCompare.com discusses Aquastats.

Flue gas

Flue gas is gas that enters the atmosphere by way of a pipe or flue on a particular heating unit. Flue gases from boilers can sometimes contain pollutants, but these can be controlled or condensed. Flue dilution fans installed in used boilers will help alleviate excessive contaminates from entering the atmosphere.
Try: For more on flue gas, go to Flue Gas Analyzer. Read about flue gas condensers at The Boiler Burner Consortium.