On-demand steam wasn’t the original plan, but it was just what the doctor ordered for performance and budget.
Selecting and purchasing equipment to supply heat and steam for essential services at Shelby Baptist Medical Center’s (SBMC) new $94 million South Tower and central energy plant was a big decision that required the input of many people, including engineers, contractors, facilities managers, and medical center administrators. Ultimately, however, the decision fell on facilities director Frank Hutchinson, who selected three Miura EXN-300SGO dual-fuel steam boilers for maximum steam generation efficiency at SBMC’s new facility, in Alabaster AL.
His initial interest in Miura was sparked by a magazine report about a recent Miura boiler installation at a major university hospital. The article referenced ways in which Miura’s highly efficient, modular design, and on-demand steam technology can dramatically reduce fuel costs compared with traditional firetube boilers. Intrigued by these possibilities, Hutchinson investigated further and, while attending a hospital trade show, met Craig Simons of Marspec Technical Products (Spanish Fort, AL), who was displaying information about Miura’s eco-friendly boilers.
Simons provided additional information and placed Hutchinson in contact with the facilities director at the university hospital featured in the article. The manager told Hutchinson of the tremendous fuel savings the new boilers brought to his facility.
“While I was checking references, I spoke with my counterpart at the other hospital,” said Hutchinson. “He told me that he was unfamiliar with Miura at first, but is now very glad he installed their boilers. He also said that after the first month of operation, the local gas company came by and replaced its meter because his gas consumption had dropped so much they assumed their meter was broken, which it wasn’t.”
Encouraged by this, Hutchinson spoke with several other current users of Miura boilers, including a manager at a local industrial laundry. During this conversation, Hutchinson learned that the laundry manager, who is currently using Miura boilers, was a former boiler operator at a regional medical center in Tuscaloosa that did not use Miura. The laundry manager provided Hutchinson with a firsthand comparison of the two boiler systems in terms relevant to a hospital facilities director. These comments confirmed his decision to choose Miura, even though an engineering firm consulting on the project had already committed to installing three older-style units from another manufacturer.
“I looked at the engineering plan and sat down with Marspec to do the numbers. We found that only three 300 bhp units were needed instead of the proposed three 400 bhp boiler configuration,” said Hutchinson. “I made them [the engineering firm] run the numbers again, and they agreed that I was right and acknowledged the projected $60,000 per year savings on natural gas costs revealed by the calculations.” Taking matters into his own hands, Hutchinson rejected the engineering firm’s plan and substituted three 300 bhp Miura EXN-300SGO dual-fuel boilers to replace the four proposed units.
“I really stuck my neck out on this one, but it was the right thing to do, and I’m very glad I did,” added Hutchinson.
ABOUT THE SBMC PROJECTThe recently completed SBMC South Tower Project consists of a new 167,712-sq-ft, four-story bed tower that houses 101 patient beds and provides additional space for other hospital services including a surgery center, clinical laboratory, central sterile supply department, an admitting/registration area, public space, and mechanical space. The new tower is powered by a new 15,000-sq-ft central energy plant, with three 300 bhp Miura EXN-300SGO dual-fuel boilers providing steam for heating the tower as well as powering a surgery center and the hospital’s central sterilization unit.
Installation of the Miura boilers was performed by Marspec Technical products, under the supervision of Craig Simons.
PATHS TO SAVINGSSince the opening of the South Tower in December 2009, the new Miura boilers have been proving their value. According to Hutchinson, “The new bed tower encompasses more square footage than the old hospital wing, and we have moved the surgery center, cath lab, and central sterilization into the new tower as well. Even with this substantially larger load, we are seeing a 35% to 50% reduction in fuel costs compared with running the old facility. And with annual fuel costs exceeding $400,000, these new Miura boilers can pay for themselves in just a few years' time.”
While the new tower’s design incorporates a number of energy-saving features in its design and construction, Hutchinson still attributes about 30% of the energy savings to the boilers.
Miura boilers save money in a number of ways. First, their unique on-demand steam technology employs a once-through design that eliminates the lengthy startup times associated with conventional firetube boilers. Miura boilers can produce usable steam output in five minutes, as opposed to the up to two hours conventional boilers require just to warm up. Miura’s boiler design translates into huge savings on fuel costs and eliminates the need for many hours of full-power operation each week.
Second, the rapid start-up of Miura on-demand steam boilers allows multiple installation (MI) users to turn off any boilers that are not in use. This eliminates the fuel expense involved in having boilers idling in standby mode.
Third, Miura’s modular design allows MI boilers to be switched on and off to match varying load demands throughout the day. The system is able to automatically respond within seconds to increased demand and then switch to standby once the demand has been met. Since Miura boilers heat much smaller quantities of water than larger firetube boilers, turning a boiler off results in far less radiant losses than that which occur with firetube units, since their larger volume pressure vessels have more surface area for heat to escape into the surrounding air.
Finally, Miura boilers can conserve water and save on water-treatment costs. In a hospital setting, rapid startup times allow Miura boilers not in use to remain off, while firetube boilers must remain idling in standby. When in standby mode, firetube boilers are still cycling, creating steam and blowing down. This cycling leads to increased water consumption and consequently increased water treatment costs.
SBMC has plans to eliminate two existing 200 bhp firetube boilers in the older section of the hospital, and connect the older section to the new Miura-powered central energy plant. Remarkably, the three Miura boilers can handle the additional load without needing to install additional units. Anticipating this move, Hutchinson reports that his water-treatment company has already reduced his upcoming water treatment contract by $20,000 per year to account for the loss of the older 200 bhp boilers.
REDUCED SPACE, REDUCED EMISSIONSAnother unique feature of Miura boilers is their compact design. When incorporated in the original design plans, Miura boilers can help reduce construction costs by taking up significantly less space than conventional boilers. At SBMC, however, original construction plans remained in place despite the substitution for Miura boilers.
“The Miura boilers take up a lot less space than the previously proposed firetube units,” said Hutchinson. “While we left the placement of them the same as what was specified in the engineering plan, the boilers are spaced comfortably far apart. We even have room to add additional boilers should the need arise.”
In addition to their money-saving design, Miura boilers produce fewer emissions than conventional boilers. Miura outputs reduced levels of nitrogen oxides (NOx), a major contributor to air pollution, as well as CO2, the most prevalent of greenhouse gases. Miura boilers accomplish this by reducing the temperature of the boiler’s flame, which in turn reduces the amount of excited nitrogen atoms available to bond with oxygen to form nitrogen oxides. As a result, NOx emissions are reduced to around one-quarter of what traditional boilers emit and comply with even the most stringent air quality regulations.
THE RIGHT DECISIONHutchinson and SBMC couldn’t be more pleased with the performance of their new Miura boilers and the savings they are achieving. They expect to realize even greater savings when boilers in the older section of the medical center are turned off for good.
“Being placed in charge of deciding what type of boiler SBMC would rely on for many years to come was a big responsibility, which I didn’t take lightly,” said Hutchinson. “In that position, the easiest thing to do would have been to go along with the engineers’ recommendations. But, I did my own research and discovered a better solution to SBMC’s needs.”
Because of this, SBMC is benefiting from reduced fuel costs and reduced use of water-treatment chemicals while the surrounding community also has cleaner air to breathe. “In my book, this is a win, win, win situation for everyone concerned,” concluded Hutchinson. TB