Oct 16 2008
The high price of fuel oil is bound to put a big dent in the pocketbooks of Long Islanders this heating season. Some homeowners may be thinking about replacing an old boiler for a more efficient one, but they are unsure if the expense of buying a new unit would be worthwhile in terms of fuel savings.
Tom Butcher, head of Brookhaven Lab's Energy Resources Division
Funded by the New York State Energy Research and Development Authority and the National Oil Heat Research Alliance (NORA), the U.S. Department of Energy’s Brookhaven National Laboratory has done extensive research on the efficiency of oil- and gas-fired hydronic home-heating systems — systems that provide both heat and hot water through baseboard radiators. The data from this recent research forms the basis of a web-based fuel-oil savings analysis calculator for consumers. The calculator will work on computers running Microsoft Windows and can be downloaded at NORA’s website: www.nora-oilheat.org.
“Along with the price of oil, the homeowner’s current heating system can be included in the calculator, and it can be compared with as many as three other systems chosen by the homeowner to determine which is most energy-efficient,” said Tom Butcher, head of Brookhaven Lab’s Energy Resources Division. “We tested 13 systems and compared their efficiency to that of a 22-year-old oil-fired, cast-iron boiler. We found that efficiency can be improved by 25 percent for one sample home by replacing older boilers with top-rated new ones, which can result in many thousands of dollars of savings over the lifetime of a new boiler. We can’t say what the exact savings will be because we don’t know what the price of oil will be in the future or the details of energy use at every home.”
While standard fuel-efficiency ratings that are used by most fuel-oil contractors are based on simple tests of space-heating efficiency only, the Brookhaven researchers used a more accurate method of measurement in their tests that takes into account the domestic hot water load, which is typically integrated with a boiler system, as well as new controls that increase efficiency.
“A lot of oil is used in the warm months just to keep the boiler hot in case hot water is needed,” Butcher said. “This was taken into account in our measurements. We imposed realistic heating loads on our test boilers, simulating use during all seasons to get accurate annual efficiency ratings. We found that summer performance of boilers has a big impact on overall fuel consumption.”
The researchers found that one oil-based non-condensing system tested — one that does not recover condensing gases to heat water — is equal in annual efficiency to the high-performance natural gas boiler that they tested – a surprising result. The BNL report that provides the basis for the calculator is also available for downloading on the NORA website.