The home heating oil industry has a long and proud history, and Fuel Oil News has been there supporting it since 1935. It is an industry that has faced many challenges during that time. In its 77th year, Fuel Oil News is doing more than just holding
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www.fueloilnews.com | FUEL OIL NEWS | MARCH 2016 39 Another advancement is 0-10 VDC output signal. This feature provides easy integration with older boilers, such as cast iron, that don't have sophisticated controls, and is especially valuable if a boiler fails in a facility with multiple boilers. With 0-10 VDC, instead of replacing all boilers, a facility can install one condensing boiler to improve efficiency and run that unit as the primary boiler. If more heat is needed, the output signal turns on an older boiler—which is most efficient at full capacity anyway—and then modulates the condensing boiler. This hybrid system improves the overall efficiency of the system and requires less initial investment for the customer. Programmable zone options also have advanced in design. In the past, boiler manufacturers offered zone pump or zone valve control- lers for maintaining separate conditions in different areas of a facility. The ease of cleaning and maintenance of condensing boilers varies based on the type of technology and material design. Stainless steel condensing boilers feature either a water tube or fire tube heat exchanger. The water tube stainless steel heat exchanger consists of water inside a spiral tube with the flue gases on the outside. These units can be more difficult to clean due to the spiral design. The fire tube, on the other hand, features the flue gases on the inside and water on the outside. These are typically straight tubes and a facil- ity manager can easily access and clean them. Aluminum condensing heat exchangers feature separate sec- tions bolted together and include a clean out plate. Inside the heat exchanger are pins to increase the heat transfer area. Maintenance personnel simply remove the front plate to access the inside of the heat exchanger. The areas between the pins can be easily cleaned and flushed with water. One new trend is predictive maintenance. With this new advancement, maintenance personnel can receive a predictive analysis of what may happen to a boiler over a specific length of time such as the next six to 12 months. Boiler Design Durability Condensing is a fairly new technology, so it's difficult to prove the durability of these units. With proper maintenance, it's likely that these units can last anywhere from 15 to 20 years. Annual efficiency monitoring of the heat transfer fluid in con- densing boilers with aluminum or stainless steel heat exchangers is recommended. Depending on the results, action can be taken to improve boiler efficiencies, resulting in lower annual operating costs. Standard, cast-iron boilers, on the other hand, can have a lon- gevity advantage. It's not uncommon for a cast iron boiler to have a useful life between 30 and 50 years. These conventional boilers are also designed to access tight spaces such as narrow hallways and small elevators, often a key factor in retrofit applications—which make up 90% of boiler installations. The installer can bring one cast iron section at a time. Another new development in improving the life of condensing heat exchangers is the development of a non-metallic condensate base, which greatly reduces heat exchanger corrosion. The Future of Boiler Design The future of boiler design is integration with renewable heat- ing sources such as solar energy, geothermal, wind and biomass. Solar energy, for example, is popular in western U.S. states to pre- heat water tanks. A solar water heater typically will not provide enough heated water by itself, but it can increase the energy efficiency of the sys- tem and work in tandem with a boiler. When water temperature drops below a certain level the boiler is activated to provide supplemental heat. In mild climates, such as on the East Coast or in the South, geothermal energy is becoming more prevalent. This applica- tion uses ground source heat pumps for heating and for cooling. Geothermal heat pumps use the natural warmth of the ground several feet below the soil to pre-heat water. A geothermal heating method can reduce the amount of natural gas, electricity or oil that a boiler uses to save energy. When more heat is needed, an electric or a conventional hydronic boiler is activated. The use of boilers installed in combination with renewable technologies and eco-friendly heating systems to improve efficien- cies is on the rise. Modern boilers have come a long way in design and technol- ogy. Today's boilers feature advanced controls, efficient heating and are easily integrated into existing boiler systems to provide lower energy costs for facility managers and building owners. l F O N John Kopf is senior product manager with Weil-McLain, based in Burr Ridge, Ill., with manufacturing in Michigan City, Ind. and Eden, N.C., and sales offices throughout the United States.